ZILLOW GROUP, INC., 10-K filed on 2/21/2019
Annual Report
v3.10.0.1
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2018
Feb. 15, 2019
Jun. 30, 2018
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Entity Emerging Growth Company false    
Entity Small Business false    
Entity Shell Company false    
Document Period End Date Dec. 31, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Trading Symbol ZG    
Entity Registrant Name ZILLOW GROUP, INC.    
Entity Central Index Key 0001617640    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 10,442,769,057
Class A Common Stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   58,111,740  
Class B Common Stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   6,217,447  
Class C Capital Stock      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   140,268,416  
v3.10.0.1
Consolidated Balance Sheets - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Current assets:    
Cash and cash equivalents $ 651,058 $ 352,095
Short-term investments 903,867 410,444
Accounts receivable, net of allowance for doubtful accounts of $4,838 and $5,341 at December 31, 2018 and 2017, respectively 66,083 54,396
Inventory 162,829 0
Mortgage loans held for sale 35,409 0
Prepaid expenses and other current assets 61,067 24,590
Restricted cash 12,385 0
Total current assets 1,892,698 841,525
Contract cost assets 45,819 0
Property and equipment, net 135,172 112,271
Goodwill 1,984,907 1,931,076
Intangible assets, net 215,904 319,711
Other assets 16,616 25,934
Total assets 4,291,116 3,230,517
Current liabilities:    
Accounts payable 7,471 3,587
Accrued expenses and other current liabilities 63,101 61,373
Accrued compensation and benefits 31,388 19,109
Revolving credit facility 116,700 0
Warehouse lines of credit 33,018 0
Deferred revenue 34,080 31,918
Deferred rent, current portion 1,740 2,400
Total current liabilities 287,498 118,387
Deferred rent, net of current portion 19,945 21,330
Long-term debt 699,020 385,416
Deferred tax liabilities and other long-term liabilities 17,474 44,561
Total liabilities 1,023,937 569,694
Commitments and contingencies (Note 19)
Shareholders’ equity:    
Preferred stock, $0.0001 par value; 30,000,000 shares authorized; no shares issued and outstanding 0 0
Additional paid-in capital 3,939,842 3,254,146
Accumulated other comprehensive loss (905) (1,100)
Accumulated deficit (671,779) (592,243)
Total shareholders’ equity 3,267,179 2,660,823
Total liabilities and shareholders’ equity 4,291,116 3,230,517
Class A Common Stock    
Shareholders’ equity:    
Common stock 6 6
Class B Common Stock    
Shareholders’ equity:    
Common stock 1 1
Class C Capital Stock    
Shareholders’ equity:    
Common stock $ 14 $ 13
v3.10.0.1
Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Accounts receivable, allowance for doubtful accounts $ 4,838 $ 5,341
Preferred stock, par value (usd per share) $ 0.0001 $ 0.0001
Preferred stock, shares authorized (in shares) 30,000,000 30,000,000
Preferred stock, shares issued (in shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Class A Common Stock    
Common stock, par value (usd per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 1,245,000,000 1,245,000,000
Common stock, shares issued (in shares) 58,051,448 56,629,103
Common stock, shares outstanding (in shares) 58,051,448 56,629,103
Class B Common Stock    
Common stock, par value (usd per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 15,000,000 15,000,000
Common stock, shares issued (in shares) 6,217,447 6,217,447
Common stock, shares outstanding (in shares) 6,217,447 6,217,447
Class C Capital Stock    
Common stock, par value (usd per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 600,000,000 600,000,000
Common stock, shares issued (in shares) 139,635,370 127,268,598
Common stock, shares outstanding (in shares) 139,635,370 127,268,598
v3.10.0.1
Consolidated Statements of Operations - USD ($)
shares in Thousands, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenue:      
Total revenue $ 1,333,554 $ 1,076,794 $ 846,589
Cost of revenue (exclusive of amortization):      
Cost of revenue (exclusive of amortization) [1] 153,590 85,203 69,262
Sales and marketing 552,621 448,201 382,419
Technology and development 410,818 319,985 255,583
General and administrative 262,153 210,816 332,007
Impairment costs 79,000 174,000 0
Acquisition-related costs 2,332 463 1,423
Integration costs 2,015 0 0
Gain on divestiture of business 0 0 (1,251)
Total costs and expenses 1,462,529 1,238,668 1,039,443
Loss from operations (128,975) (161,874) (192,854)
Loss on debt extinguishment 0 0 (22,757)
Other income 19,270 5,385 2,711
Interest expense (41,255) (27,517) (7,408)
Loss before income taxes (150,960) (184,006) (220,308)
Income tax benefit (expense) 31,102 89,586 (130)
Net loss $ (119,858) $ (94,420) $ (220,438)
Net loss per share-basic and diluted (usd per share) $ (0.61) $ (0.51) $ (1.22)
Weighted-average shares outstanding-basic and diluted (in shares) 197,944 186,453 180,149
Amortization of website development costs and intangible assets included in technology and development $ 79,309 $ 94,349 $ 87,060
IMT      
Revenue:      
Total revenue 1,281,189 1,076,794 846,589
Cost of revenue (exclusive of amortization):      
Cost of revenue (exclusive of amortization) [1] 104,330 85,203 69,262
Homes      
Revenue:      
Total revenue 52,365 0 0
Cost of revenue (exclusive of amortization):      
Cost of revenue (exclusive of amortization) [1] $ 49,260 $ 0 $ 0
[1] Amortization of website development costs and intangible assets included in technology and development was $79,309, $94,349 and $87,060 for the periods ended December 31, 2018, 2017 and 2016, respectively.
v3.10.0.1
Consolidated Statements of Comprehensive Loss - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Statement of Comprehensive Income [Abstract]      
Net loss $ (119,858) $ (94,420) $ (220,438)
Other comprehensive income (loss):      
Unrealized gains (losses) on investments 144 (858) 229
Currency translation adjustments 51 0 0
Total other comprehensive income (loss) 195 (858) 229
Comprehensive loss $ (119,663) $ (95,278) $ (220,209)
v3.10.0.1
Consolidated Statements of Shareholders' Equity - USD ($)
$ in Thousands
Total
Class A Common Stock, Class B Common Stock and Class C Capital Stock
Additional Paid-In Capital
Accumulated Deficit
Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2015 $ 2,679,053 $ 18 $ 2,956,111 $ (276,605) $ (471)
Beginning Balance (in shares) at Dec. 31, 2015   178,474,917      
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Issuance of common and capital stock upon exercise of stock options 31,211 $ 0 31,211    
Issuance of common and capital stock upon exercise of stock options (in shares)   2,518,172      
Vesting of restricted stock units 0   0    
Vesting of restricted stock units (in shares)   1,487,263      
Shares and value of restricted stock units withheld for tax liability (616)   (616)    
Shares and value of restricted stock units withheld for tax liability (in shares)   (21,634)      
Share-based compensation expense 116,979   116,979    
Portion of repurchase price recorded in additional paid-in capital in connection with partial repurchase/conversion of 2020 (127,615)   (127,615)    
Equity component of issuance of 2021 Notes, net of issuance costs of $2,494 91,400   91,400    
Premiums paid for Capped Call Confirmations (36,616)   (36,616)    
Net loss (220,438)   0 (220,438)  
Other comprehensive income (loss) 229     0 229
Ending Balance at Dec. 31, 2016 2,533,587 $ 18 3,030,854 (497,043) (242)
Ending Balance (in shares) at Dec. 31, 2016   182,458,718      
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Issuance of common and capital stock upon exercise of stock options 98,072 $ 2 98,070    
Issuance of common and capital stock upon exercise of stock options (in shares)   6,202,421      
Vesting of restricted stock units 0   0    
Vesting of restricted stock units (in shares)   1,463,825      
Shares and value of restricted stock units withheld for tax liability (365)   (365)    
Shares and value of restricted stock units withheld for tax liability (in shares)   (9,816)      
Share-based compensation expense 124,807   124,807    
Net loss (94,420)   0 (94,420)  
Other comprehensive income (loss) (858)       (858)
Ending Balance at Dec. 31, 2017 2,660,823 $ 20 3,254,146 (592,243) (1,100)
Ending Balance (in shares) at Dec. 31, 2017   190,115,148      
Increase (Decrease) in Stockholders' Equity [Roll Forward]          
Issuance of common and capital stock upon exercise of stock options 120,074   120,074    
Issuance of common and capital stock upon exercise of stock options (in shares)   5,472,728      
Vesting of restricted stock units 0        
Vesting of restricted stock units (in shares)   1,740,134      
Shares and value of restricted stock units withheld for tax liability (70)   (70)    
Shares and value of restricted stock units withheld for tax liability (in shares)   (1,489)      
Share-based compensation expense 157,674   157,674    
Portion of conversion recorded in additional paid-in-capital in connection with partial conversion of 2020 Notes 500   500    
Portion of conversion recorded in additional paid-in-capital in connection with partial conversion of 2020 Notes (in shares)   20,727      
Issuance of Class C capital stock in connection with equity offering, net of issuance costs 360,346 $ 1 360,345    
Issuance of Class C capital stock in connection with equity offering, net of issuance costs (in shares)   6,557,017      
Equity component of issuance of 2021 Notes, net of issuance costs of $2,494 76,587   76,587    
Premiums paid for Capped Call Confirmations (29,414)   (29,414)    
Net loss (119,858)     (119,858)  
Other comprehensive income (loss) 195       195
Ending Balance at Dec. 31, 2018 $ 3,267,179 $ 21 $ 3,939,842 $ (671,779) $ (905)
Ending Balance (in shares) at Dec. 31, 2018   203,904,265      
v3.10.0.1
Consolidated Statements of Shareholders' Equity (Parenthetical)
$ in Thousands
12 Months Ended
Dec. 31, 2018
USD ($)
Statement of Stockholders' Equity [Abstract]  
Senior notes, issuance costs $ 2,047
Capital stock, issuance costs $ 13,425
v3.10.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Operating activities      
Net loss $ (119,858) $ (94,420) $ (220,438)
Adjustments to reconcile net loss to net cash provided by operating activities, net of amounts assumed in connection with acquisitions:      
Depreciation and amortization 99,391 110,155 100,590
Share-based compensation expense 149,084 113,571 106,918
Amortization of contract cost assets 36,013 0 0
Gain on debt extinguishment 0 0 22,757
Amortization of discount and issuance costs on 2021 and 2023 Notes 26,672 18,012 883
Impairment costs 79,000 174,000 0
Deferred income taxes (31,102) (89,586) (1,370)
Loss on disposal of property and equipment 3,617 5,678 3,689
Gain on divestiture of businesses, net 0 0 (1,360)
Bad debt expense 869 7,349 2,681
Deferred rent (2,045) 7,085 1,730
Amortization (accretion) of bond premium (discount) (4,313) 431 1,489
Changes in operating assets and liabilities:      
Accounts receivable (12,556) (21,203) (13,324)
Inventory (162,829) 0 0
Mortgage loans held for sale (1,161) 0 0
Prepaid expenses and other assets (34,068) 10,807 (13,260)
Contract cost assets (41,510) 0 0
Accounts payable 1,311 (373) 856
Accrued expenses and other current liabilities 1,920 19,000 (5,065)
Accrued compensation and benefits 11,291 (4,948) 12,463
Deferred revenue 2,162 2,633 7,794
Other long-term liabilities 1,962 0 1,612
Net cash provided by operating activities 3,850 258,191 8,645
Investing activities      
Proceeds from maturities of investments 399,228 259,227 199,369
Proceeds from maturities of investments (901,761) (407,032) (175,210)
Proceeds from sales of investments 13,567 0 4,963
Purchases of property and equipment (66,054) (66,728) (62,060)
Purchases of intangible assets (12,481) (11,907) (9,662)
Purchases of cost method investments 0 (10,000) (10,000)
Proceeds from divestiture of businesses 0 579 3,200
Cash paid for acquisitions, net (55,138) (11,533) (16,319)
Net used in investing activities (622,639) (247,394) (65,719)
Financing activities      
Proceeds from issuance of 2021 Notes, net of issuance costs 364,020 0 447,784
Premiums paid for Capped Call Confirmations (29,414) 0 (36,616)
Proceeds from issuance of Class C Capital Stock, net of issuance costs 360,345 0 0
Proceeds from borrowing on revolving credit facility 116,700 0 0
Proceeds from borrowing on warehouse lines of credit 482 0 0
Partial repurchase of 2020 Notes 0 0 (370,235)
Proceeds from exercise of stock options 120,074 98,071 31,211
Value of equity awards withheld for tax liability (70) (365) (616)
Contingent merger consideration (2,000) 0 0
Net cash provided by financing activities 930,137 97,706 71,528
Net increase in cash and cash equivalents during period 311,348 108,503 14,454
Cash and cash equivalents at beginning of period 352,095 243,592 229,138
Cash, cash equivalents and restricted cash at end of period 663,443 352,095 243,592
Supplemental disclosures of cash flow information      
Cash paid for interest 15,473 9,198 6,325
Noncash transactions:      
Capitalized share-based compensation 8,590 11,236 10,061
Write-off of fully depreciated property and equipment 22,364 15,004 14,564
Write-off of fully amortized intangible assets $ 12,999 $ 5,473 $ 9,293
v3.10.0.1
Organization and Description of Business
12 Months Ended
Dec. 31, 2018
Accounting Policies [Abstract]  
Organization and Description of Business Organization and Description of Business
Zillow Group, Inc. operates the largest portfolio of real estate and home-related brands on mobile and the web which focus on all stages of the home lifecycle: renting, buying, selling and financing. Zillow Group is committed to empowering consumers with unparalleled data, inspiration and knowledge around homes and connecting them with great real estate professionals. The Zillow Group portfolio of consumer brands includes Zillow, Trulia, Mortgage Lenders of America, L.L.C. (“MLOA”), StreetEasy, HotPads, Naked Apartments, RealEstate.com and Out East. In addition, Zillow Group provides a comprehensive suite of marketing software and technology solutions to help real estate professionals maximize business opportunities and connect with millions of consumers. Beginning in April 2018, Zillow Offers provides homeowners in certain metropolitan areas with the opportunity to receive offers to purchase their home from Zillow. When Zillow buys a home, it makes certain repairs and lists the home for resale on the open market. Beginning in October 2018, Zillow also provides consumers with the opportunity to receive mortgage financing through MLOA, a licensed mortgage lender. Zillow Group operates a number of business brands for real estate, rental and mortgage professionals, including Mortech, dotloop, Bridge Interactive and New Home Feed. Zillow, Inc. was incorporated as a Washington corporation in December 2004, and we launched the initial version of our website, Zillow.com, in February 2006. Zillow Group, Inc. was incorporated as a Washington corporation in July 2014 in connection with our acquisition of Trulia, Inc. (“Trulia”). Upon the closing of the Trulia acquisition in February 2015, each of Zillow, Inc. and Trulia became wholly owned subsidiaries of Zillow Group.
Certain Significant Risks and Uncertainties
We operate in a dynamic industry and, accordingly, can be affected by a variety of factors. For example, we believe that changes in any of the following areas could have a significant negative effect on us in terms of our future financial position, results of operations or cash flows: rates of revenue growth; our ability to manage advertising inventory or pricing; engagement and usage of our products; our investment of resources to pursue strategies that may not prove effective; competition in our market; the stability of the residential real estate market and the impact of interest rate changes; changes in government regulation affecting our business; outcomes of legal proceedings; natural disasters and catastrophic events; scaling and adaptation of existing technology and network infrastructure; management of our growth; our ability to attract and retain qualified employees and key personnel; our ability to successfully integrate and realize the benefits of our past or future strategic acquisitions or investments; protection of customers’ information and other privacy concerns; protection of our brand and intellectual property; and intellectual property infringement and other claims, among other things.
v3.10.0.1
Summary of Significant Accounting Policies
12 Months Ended
Dec. 31, 2018
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies Summary of Significant Accounting Policies
Basis of Presentation
The accompanying consolidated financial statements include Zillow Group, Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. These consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”).
Use of Estimates
The preparation of financial statements in conformity with GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. On an ongoing basis, we evaluate our estimates, including those related to the net realizable value of inventory, amortization period and recoverability of contract cost assets, website and software development costs, recoverability of long-lived assets and intangible assets with definite lives, share-based compensation, income taxes, business combinations, and the recoverability of goodwill and indefinite-lived intangible assets, among others. To the extent there are material differences between these estimates, judgments, or assumptions and actual results, our financial statements will be affected.
Concentrations of Credit Risk
Financial instruments, which potentially subject us to concentrations of credit risk, consist primarily of cash and cash equivalents, investments, accounts receivable and mortgage loans held for sale. We place cash and cash equivalents and investments with major financial institutions, which management assesses to be of high credit quality, in order to limit exposure of our investments.
Credit risk with respect to accounts receivable is dispersed due to the large number of customers. There were no customers that comprised 10% or more of our total accounts receivable as of December 31, 2018 and 2017. Further, our credit risk on accounts receivable is mitigated by the relatively short payment terms that we offer. Collateral is not required for accounts receivable. We maintain an allowance for doubtful accounts such that receivables are stated at net realizable value.
Similarly, our credit risk on mortgage loans held for sale is dispersed due to a large number of customers. Further, our credit risk on mortgage loans held for sale is mitigated by the fact that we typically sell mortgages on the secondary market within a relatively short period of time after the loan is originated.
Cash and Cash Equivalents
Cash includes demand deposits with banks or financial institutions. Cash equivalents include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Our cash equivalents include only investments with original maturities of three months or less. We regularly maintain cash in excess of federally insured limits at financial institutions.
Short-term Investments
Our investments consist of fixed income securities, which include U.S. and foreign government agency securities, corporate notes and bonds, commercial paper, municipal securities and certificates of deposit, and are classified as available-for-sale securities. As the investments are available to support current operations, our available-for-sale securities are classified as short-term investments. Available-for-sale securities are carried at fair value with unrealized gains and losses reported as a component of accumulated other comprehensive loss in shareholders’ equity, while realized gains and losses and other-than-temporary impairments are reported as a component of net loss based on specific identification. An impairment charge is recorded in the consolidated statements of operations for declines in fair value below the cost of an individual investment that are deemed to be other than temporary. We assess whether a decline in value is temporary based on the length of time that the fair market value has been below cost, the severity of the decline and the intent and ability to hold or sell the investment. We did not identify any investments as other-than-temporarily impaired as of December 31, 2018 or 2017.
Restricted Cash
Restricted cash consists of amounts funded to the reserve and collection accounts related to our Revolving Credit Facility (see Note 14) and amounts held in escrow related to funding home purchases in our mortgage originations business.
Accounts Receivable and Allowance for Doubtful Accounts
Accounts receivable represent our unconditional right to consideration. Accounts receivable are generally due within 30 days and are recorded net of the allowance for doubtful accounts. We consider accounts outstanding longer than the contractual terms past due. We review accounts receivable on a regular basis and estimate an amount of losses for uncollectible accounts based on our historical collections experience, age of the receivable, knowledge of the customer and the condition of the general economy and industry as a whole. We record changes in our estimate to the allowance for doubtful accounts through bad debt expense and relieve the allowance when accounts are ultimately determined to be uncollectible. Bad debt expense is included in general and administrative expenses.
Mortgage Loans Held for Sale
Mortgage loans held for sale includes residential mortgages originated for sale in the secondary market in connection with our October 2018 acquisition of MLOA. We have elected the fair value option for all mortgage loans held for sale as election of this option allows for a better offset of the changes in fair values of the loans and the derivative instruments used to economically hedge them without having to apply complex hedge accounting provisions. Mortgage loans held for sale are initially recorded at fair value based on either sale commitments or current market quotes and are adjusted for subsequent changes in fair value until the loans are sold. Net origination costs and fees associated with mortgage loans are recognized at the time of origination. We sell substantially all of the mortgages we originate and the related servicing rights to third-party purchasers. Interest income is earned from the date a mortgage loan is originated until the loan is sold and is classified within other income in the consolidated statements of operations.
Substantially all of the mortgage loans originated are sold within a short period of time in the secondary mortgage market on a servicing released, nonrecourse basis, which limits exposure to nonperformance by loan buyer counterparties although we remain liable for certain limited representations and warranties related to loan sales, such as non-compliance with defined loan origination or documentation standards, including misstatement in the loan documents, early payoff or default on payments. Mortgage investors could seek to have us buy back loans or compensate them for losses incurred on mortgages we have sold based on claims that we breached our limited representations and warranties. We have established reserves for probable losses.
Loan Commitments and Related Derivatives
We are party to interest rate lock commitments (“IRLCs”), which are extended to borrowers who have applied for loan funding and meet defined credit and underwriting criteria in connection with our October 2018 acquisition of MLOA. IRLCs are accounted for as derivative instruments recorded at fair value with gains and losses recognized in revenue in the consolidated statements of operations. We manage our interest rate risk related to IRLCs and mortgage loans held for sale through the use of derivative instruments, generally forward contracts on mortgage-backed securities (“MBS”), which are commitments to either purchase or sell a specified financial instrument at a specified future date for a specified price, and mandatory loan commitments, which are an obligation by an investor to buy loans at a specified price within a specified time period. We do not enter into or hold derivatives for trading or speculative purposes and our derivatives are not designated as hedging instruments. Changes in the fair value of our derivative financial instruments are recognized in revenues in our consolidated statements of operations, and the fair values are reflected in other assets or other liabilities, as applicable. The net change in fair value was not significant for the year ended December 31, 2018.
There are no credit-risk-related contingent features within our derivative agreements, and counterparty risk is considered minimal. Gains and losses on IRLCs are substantially offset by corresponding gains or losses on forward contracts on mortgage-backed securities and mandatory loan commitments. We are generally not exposed to variability in cash flows of derivative instruments for more than approximately 90 days.
Inventory
Inventory is comprised of homes acquired through our Zillow Offers program and is stated at the lower of cost or net realizable value. Homes are removed from inventory on a specific identification basis when they are resold. Stated cost includes consideration paid to acquire and update each home including associated allocated overhead costs. Work-in-progress inventory includes homes undergoing updates and finished goods inventory includes homes ready for resale. Unallocated overhead costs are expensed as incurred and included in cost of revenue. Selling costs, including commissions, escrow and title fees, staging, and holding costs, including utilities, taxes and maintenance, are expensed as incurred and included in sales and marketing expenses.
Each quarter we review the value of homes held in inventory for indicators that net realizable value is lower than cost. When evidence exists that the net realizable value of inventory is lower than its cost, the difference is recognized in cost of revenue.
Contract Cost Assets
We capitalize certain incremental costs of obtaining contracts with customers which we expect to recover. These costs relate to commissions paid to sales personnel, primarily for our Premier Agent and Premier Broker programs. As a practical expedient, we recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that we otherwise would have recognized is one year or less. Capitalized commission costs are recorded as contract cost assets in our consolidated balance sheets. Contract cost assets are amortized to expense on a straight-line basis over a period that is consistent with the transfer to the customer of the products or services to which the asset relates, generally the estimated life of the customer relationship. Amortization expense related to contract cost assets is included in sales and marketing expenses in our consolidated statements of operations. In determining the estimated life of our customer relationships, we consider quantitative and qualitative data, including, but not limited to, historical customer data, recent changes or expected changes in product or service offerings, and changes in how we monetize our products and services. The amortization period for capitalized contract costs related to our Premier Agent and Premier Broker programs ranges from two to three years.
Property and Equipment
Property and equipment is recorded at cost and depreciated using the straight-line method over the estimated useful lives of the related assets. The useful lives are as follows:
 
Computer equipment
  
2 to 3 years
Office equipment, furniture and fixtures
  
5 to 7 years
Leasehold improvements
  
Shorter of expected useful life or lease term

Maintenance and repair costs are charged to expense as incurred. Major improvements, which extend the useful life of the related asset, are capitalized. Upon disposal of a fixed asset, we record a gain or loss based on the difference between the proceeds received and the net book value of the disposed asset.
Website and Software Development Costs
The costs incurred in the preliminary stages of development are expensed as incurred. Once an application has reached the development stage, internal and external costs, if direct and incremental and deemed by management to be significant, are capitalized in property and equipment and amortized on a straight-line basis over their estimated useful lives. Maintenance and enhancement costs, including those costs in the post-implementation stages, are typically expensed as incurred, unless such costs relate to substantial upgrades and enhancements to the website or software that result in added functionality, in which case the costs are capitalized and amortized on a straight-line basis over the estimated useful lives. Amortization expense related to capitalized website and software development costs is included in technology and development expense.
Capitalized development activities placed in service are amortized over the expected useful lives of those releases, currently estimated at one to three years. The estimated useful lives of website and software development activities are reviewed frequently and adjusted as appropriate to reflect upcoming development activities that may include significant upgrades and/or enhancements to the existing functionality.
Construction-in-progress primarily consists of website development costs that are capitalizable, but for which the associated applications had not been placed in service.
Recoverability of Goodwill and Indefinite-Lived Intangible Assets
Goodwill represents the excess of the cost of an acquired business over the fair value of the assets acquired at the date of acquisition, and is not amortized. We assess the impairment of goodwill on an annual basis, in our fourth quarter, or whenever events or changes in circumstances indicate that goodwill may be impaired. Typically, we choose to forgo the initial qualitative assessment and perform a quantitative analysis to assist in our annual evaluation. If impairment exists, the carrying value of the goodwill is reduced to fair value through an impairment charge recorded in our statements of operations.
Our indefinite-lived intangible asset is not amortized, and we assess the asset for impairment on an annual basis, in our fourth quarter, or whenever events or changes in circumstances indicate that the asset may be impaired. On an interim basis we consider if there are any events and circumstances that could affect the significant inputs used to determine the fair value of the indefinite-lived intangible asset, including, but not limited to, costs that could have a negative effect on future expected earnings and cash flows, changes in certain key performance metrics, and changes in management, key personnel, strategy or customers. In our evaluation of our trade names and trademarks indefinite-lived intangible asset, we typically first perform a qualitative assessment to determine whether the fair value of the indefinite-lived intangible asset is more likely than not impaired. If so, we perform a quantitative assessment and an impairment charge is recorded in our statements of operations for the excess of the carrying value of the indefinite-lived intangible asset over its fair value.
During the years ended December 31, 2018 and December 31, 2017, we recorded non-cash impairments for $69.0 million and $174.0 million related to the indefinite-lived Trulia trade names and trademarks intangible asset. For additional information about the non-cash impairments, see Note 11 to our consolidated financial statements.
Intangible Assets
We purchase and license data content from multiple data providers. This data content consists of U.S. county data about home details (e.g., the number of bedrooms, bathrooms, square footage) and other information relating to the purchase price of homes, both current and historical, as well as imagery, mapping and parcel data that is displayed on our mobile applications and websites. Our home details data not only provides information about a home and its related transactions which is displayed on our mobile applications and websites, but is also used in our proprietary valuation algorithms to produce Zestimates, Rent Zestimates and Zillow Home Value Indexes. License agreement terms vary by vendor. In some instances, we retain perpetual rights to this information after the contract ends; in other instances, the information and data are licensed only during the fixed term of the agreement. Additionally, certain data license agreements provide for uneven payment amounts throughout the contract term.
We capitalize payments made to third parties for data licenses that we expect to provide future economic benefit through the recovery of the costs of these arrangements via the generation of our revenue and margins. For data license contracts that include uneven payment amounts, we capitalize the payments as they are made as an intangible asset and the total contract value is typically amortized on a straight-line basis over the term of the contract, which is equivalent to the estimated useful life of the asset. We evaluate data content contracts for potential capitalization at the inception of the arrangement as well as each time periodic payments to third parties are made.
The amortization period for the capitalized purchased content is based on our best estimate of the useful life of the asset, which is approximately five years. The determination of the useful life includes consideration of a variety of factors including, but not limited to, our assessment of the expected use of the asset and contractual provisions that may limit the useful life, as well as an assessment of when the data is expected to become obsolete based on our estimates of the diminishing value of the data over time. We evaluate the useful life of the capitalized purchased data content each reporting period to determine whether events and circumstances warrant a revision to the remaining useful life. If we determine the estimate of the asset’s useful life requires modification, the carrying amount of the asset is amortized prospectively over the revised useful life. The capitalized purchased data content is amortized on a straight-line basis as the pattern of delivery of the economic benefits of the data cannot reliably be determined because we do not have the ability to reliably predict future traffic to our mobile applications and websites.
Under certain other data agreements, the underlying data is obtained on a subscription basis with consistent monthly or quarterly recurring payment terms over the contractual period. Upon the expiration of such arrangements, we no longer have the right to access the related data, and therefore, the costs incurred under such contracts are not capitalized and are expensed as payments are made. We would immediately lose rights to data under these arrangements if we were to cancel the subscription and/or cease making payments under the subscription arrangements.
We also capitalize costs related to the license of certain internal-use software from third parties, including certain licenses of software in cloud computing arrangements. Additionally, we capitalize costs incurred during the application development stage related to the development of internal-use software and enterprise cloud computing services. We expense costs as incurred related to the planning and post-implementation phases of development. Capitalized internal-use software costs are amortized over the estimated useful life of the asset, which is currently one to 3 years, on a straight-line basis.
Intangibles-in-progress consist of purchased content and software that are capitalizable but have not been placed in service.
We also have intangible assets for developed technology, customer relationships, trade names and trademarks and advertising relationships which we recorded in connection with acquisitions. Purchased intangible assets with a determinable economic life are carried at cost, less accumulated amortization. These intangible assets are amortized over the estimated useful life of the asset on a straight-line basis.
Recoverability of Intangible Assets with Definite Lives and Other Long-Lived Assets
We evaluate intangible assets and other long-lived assets for impairment whenever events or circumstances indicate that they may not be recoverable. Recoverability is measured by comparing the carrying amount of an asset group to future undiscounted net cash flows expected to be generated. We group assets for purposes of such review at the lowest level for which identifiable cash flows of the asset group are largely independent of the cash flows of the other groups of assets and liabilities. If this comparison indicates impairment, the amount of impairment to be recognized is calculated as the difference between the carrying value and the fair value of the asset group.
Deferred Revenue
Deferred revenue consists of prepaid advertising fees received or billed in advance of satisfying our performance obligations and prepaid but unrecognized subscription revenue. Deferred revenue is recognized when or as we satisfy our obligations under contracts with customers.
Deferred Rent
For our operating leases, we recognize rent expense on a straight-line basis over the terms of the leases and, accordingly, we record the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. For office space under an operating lease that is subleased to a third party for which we intend to reoccupy the space at a future date, rent expense is recognized net of sublease income. Landlord-funded leasehold improvements are also recorded as deferred rent liabilities and are amortized as a reduction of rent expense over the non-cancelable term of the related operating lease.
Business Combinations
We recognize identifiable assets acquired and liabilities assumed at their acquisition date fair values. Goodwill as of the acquisition date is measured as the excess of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. While we use our best estimates and assumptions for the purchase price allocation process to value assets acquired and liabilities assumed at the acquisition date, our estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, we record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill to the extent that we identify adjustments to the preliminary purchase price allocation. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to our consolidated statements of operations. We recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined.
Revenue Recognition
We recognize revenue when (or as) we satisfy our performance obligations by transferring control of the promised products or services to our customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those products or services.
As a practical expedient, we do not adjust the promised amount of consideration for the effects of a significant financing component as the period between our transfer of a promised product or service to a customer and when the customer pays for that product or service is one year or less.
We do not disclose the transaction price related to remaining performance obligations for (i) contracts with an original expected duration of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for performance completed to date. The remaining duration of our performance obligations is generally less than one year.
In our Internet, Media & Technology (“IMT”) segment, we generate revenue from the sale of advertising services and our suite of marketing software and technology solutions to businesses and professionals primarily associated with the residential real estate, rental and mortgage industries. These professionals include real estate, rental and mortgage professionals and brand advertisers. Our four primary revenue categories within our IMT segment are Premier Agent, Rentals, Mortgages and Other.
In our Homes segment, we generate revenue from the resale of homes on the open market through our Zillow Offers program.
Premier Agent Revenue. Premier Agent revenue is derived from our Premier Agent and Premier Broker programs. Our Premier Agent and Premier Broker programs offer a suite of marketing and business technology products and services to help real estate agents and brokers achieve their advertising goals, while growing and managing their businesses and brands. All Premier Agents and Premier Brokers receive access to a dashboard portal on our mobile application or website that provides individualized program performance analytics, our customer relationship management, or CRM, tool that captures detailed information about each contact made with a Premier Agent or Premier Broker through our mobile and web platforms and our account management tools. We have concluded that the marketing and business technology products and services promised to Premier Agents and Premier Brokers represent distinct performance obligations.
We primarily offer our Premier Agent and Premier Broker advertising products on a cost per impression basis. Payment is received prior to the delivery of impressions. Impressions are delivered when a sold advertisement appears on pages viewed by users of our mobile applications and websites. We determine the cost per impression delivered in each zip code using an auction-based pricing method in consideration of the total amount spent by Premier Agents and Premier Brokers to purchase impressions in the zip code during the month. A Premier Agent’s or Premier Broker’s share of voice in a zip code is determined by their proportional monthly budgeted spend in that zip code as a percentage of the total monthly budgeted spend of all Premier Agents and Premier Brokers in that zip code. The cost per impression that we charge is dynamic - as demand for impressions in a zip code increases or decreases, the cost per impression in that zip code may be increased or decreased accordingly. The price paid for each impression is representative of the price at which we would sell an impression separately to a customer, or the stand-alone selling price.
We have not allocated the transaction price to each performance obligation as the amounts recognized would be the same irrespective of any allocation. As such, we recognize revenue related to the Premier Agent and Premier Broker products and services based on the contractual spend recognized on a straight-line basis during the contractual period over which the
products and services are provided. This methodology best depicts how we satisfy our performance obligations to customers, as we continuously transfer control of the performance obligations to the customer throughout the contractual period.
In October 2018, we began testing a new Flex Pricing model for Premier Broker and Premier Agent advertising services in limited markets. With the Flex Pricing model, Premier Brokers and Premier Agents are provided with validated leads at no upfront cost, and they pay a performance advertising fee only when a real estate transaction is closed with one of their leads. With this pricing model, the transaction price represents variable consideration as the amount to which we expect to be entitled varies based on the number of validated leads that convert into real estate transactions.
Rentals Revenue. Rentals revenue includes our rentals marketplace and suite of tools for rental professionals. Rentals revenue primarily includes revenue generated by advertising sold to property managers and other rental professionals on a cost per lead, cost per click or cost per lease generated basis. We recognize revenue as leads or clicks are provided to rental professionals, which is the amount for which we have the right to invoice. The number of leases generated through our rentals marketplace during the period is accounted for as variable consideration, and we estimate these amounts based on the expected number of qualified leases secured during the period. We do not believe that a significant reversal in the amount of cumulative revenue recognized will occur once the uncertainty related to the number of leases secured is subsequently resolved.
Beginning in 2018, rentals revenue also includes revenue generated from Zillow’s rental applications product through which potential renters can submit applications to multiple rental properties over a 30-day period for a flat service fee. We recognize revenue for the rental applications product on a straight-line basis during the contractual period over which the customer has the right to access and submit the rental application.
Mortgages Revenue. Mortgages revenue primarily includes marketing products sold to mortgage professionals on a cost per lead basis, including our Custom Quote and a portion of our Connect (formerly known as Long Form) services, and on a subscription basis, including a portion of our Connect service. For our Connect and Custom Quote cost per lead mortgage marketing products, participating qualified mortgage professionals typically make a prepayment to gain access to consumers interested in connecting with mortgage professionals. Mortgage professionals who exhaust their initial prepayment prepay additional funds to continue to participate in the marketplace. For our Connect subscription mortgage marketing product, participating qualified mortgage professionals generally prepay a monthly subscription fee, which they then allocate to desired geographic counties. In Zillow Group’s Connect platform, consumers answer a series of questions to find a local lender, and mortgage professionals receive consumer contact information, or leads, when the consumer chooses to share their information with a lender. Consumers who request rates for mortgage loans in Custom Quotes are presented with customized quotes from participating mortgage professionals.
For our cost per lead mortgages products, we recognize revenue when a user contacts a mortgage professional through Zillow Group’s mortgages platform, which is the amount for which we have the right to invoice. For our Connect subscription product, the opportunity to receive a consumer contact is based on the mortgage professional’s relative share of voice in a geographic county. When a consumer submits a contact, Zillow Group contacts a group of subscription mortgage professionals via text message, and the first mortgage professional to respond receives the consumer contact information. We recognize revenue based on the contractual spend recognized on a straight-line basis during the contractual period over which the service is provided. This methodology best depicts how we satisfy our performance obligation to subscription customers, as we continuously transfer control of the performance obligation to the customer throughout the contractual period.
Beginning in October 2018, mortgages revenue also includes revenue generated from our mortgage originations business. We elect the fair value option for our mortgage loans held for sale, which are initially recorded at fair value based on either sale commitments or current market quotes and are adjusted for subsequent changes in fair value until the loans are closed.
Mortgages revenue also includes revenue generated by Mortech, which provides subscription-based mortgage software solutions, including a product and pricing engine and lead management platform, for which we recognize revenue on a straight-line basis during the contractual period over which the services are provided.
Other Revenue. Other revenue primarily includes revenue generated by new construction and display, as well as revenue from the sale of various other marketing and business products and services to real estate professionals. Our new construction marketing solutions allow home builders to showcase their available inventory to home shoppers. New construction revenue primarily includes revenue generated by advertising sold to builders on a cost per residential community basis, and revenue is recognized on a straight-line basis during the contractual period over which the communities are advertised on our mobile applications and websites. Consideration is billed in arrears. Display revenue primarily consists of graphical mobile and web advertising sold on a cost per thousand impressions or cost per click basis to advertisers promoting their brands on our mobile
applications and websites. We recognize display revenue as clicks occur or as impressions are delivered to users interacting with our mobile applications or websites, which is the amount for which we have the right to invoice.
Homes Revenue. Homes revenue is derived from the resale of homes on the open market through our Zillow Offers program. Homes revenue is recognized at the time of the closing of the home sale when title to and possession of the property are transferred to the buyer.
There were no customers that generated 10% or more of our total revenue in the years ended December 31, 2018, 2017 or 2016.
Cost of Revenue
For our IMT segment, our cost of revenue consists of expenses related to operating our mobile applications and websites, including associated headcount expenses, such as salaries and benefits and share-based compensation expense and bonuses, as well as credit card fees, ad serving costs paid to third parties, revenue-sharing costs related to our commercial business relationships, depreciation expense and costs associated with the operation of our data center and mobile applications and websites. Beginning in the fourth quarter of 2018, cost of revenue within the IMT segment also includes expenses associated with our mortgage originations business, such as origination costs and fees, lead acquisition costs and expenses related to systems used directly in the origination of mortgages. For our Homes segment, our cost of revenue also consists of the consideration paid to acquire and make necessary updates to each home including associated overhead costs.
Technology and Development
Technology and development expenses consist of headcount expenses, including salaries, benefits, share-based compensation expense and bonuses for salaried employees and contractors engaged in the design, development and testing of our mobile applications and websites and the tools and applications that support our products, and equipment and maintenance costs. Technology and development expenses also include amortization costs related to capitalized website and development activities, amortization of software, amortization of certain intangibles and other data agreement costs related to the purchase of data used to populate our mobile applications and websites, amortization of intangible assets recorded in connection with acquisitions, including developed technology and customer relationships, amongst others, and depreciation expense.
Research and development costs are expensed as incurred and are recorded in technology and development expenses. For the years ended December 31, 2018, 2017 and 2016, expenses attributable to research and development for our business totaled $298.1 million, $193.0 million and $170.1 million, respectively.
Share-Based Compensation
We measure compensation expense for all share-based awards at fair value on the date of grant and recognize compensation expense over the service period on a straight-line basis for awards expected to vest.
We use the Black-Scholes-Merton option-pricing model to determine the fair value for option awards. In valuing our option awards, we make assumptions about risk-free interest rates, dividend yields, volatility, and weighted-average expected lives. In addition, through December 31, 2016, we made assumptions about estimated forfeiture rates. Beginning on January 1, 2017, we elected to account for forfeitures as they occur. Risk-free interest rates are derived from U.S. Treasury securities as of the option award grant date. Expected dividend yield is based on our historical cash dividend payments, which have been zero to date. The expected volatility for our Class A common stock and Class C capital stock is estimated using our historical volatility. The weighted-average expected life of the option awards is estimated based on our historical exercise data. Prior to January 1, 2017, forfeiture rates were estimated using historical actual forfeiture trends as well as our judgment of future forfeitures. These rates were evaluated at least quarterly and any change in share-based compensation expense was recognized in the period of the change. We considered many factors when estimating expected forfeitures, including employee class and historical experience.
For issuances of restricted stock units and restricted units, we determine the fair value of the award based on the market value of our Class A common stock or Class C capital stock, as applicable, at the date of grant.
Advertising Costs
Advertising costs are expensed as incurred. For the years ended December 31, 2018, 2017 and 2016, expenses attributable to advertising totaled $177.3 million, $156.5 million and $120.2 million, respectively. Advertising costs are recorded in sales and marketing expenses.
Income Taxes
We use the asset and liability approach for accounting and reporting income taxes, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement and tax bases of assets and liabilities at the applicable enacted tax rates. A valuation allowance against deferred tax assets would be established if, based on the weight of available evidence, it is more likely than not (a likelihood of more than 50%) that some or all of the deferred tax assets are not expected to be realized.
We establish reserves for tax-related uncertainties based on estimates of whether, and the extent to which, additional taxes will be due. We adjust these reserves in light of changing facts and circumstances, such as the closing of a tax audit, new tax legislation or the change of an estimate. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will affect the provision for income taxes in the period in which such determination is made. Interest and penalties related to unrecognized tax benefits are recorded as income tax expense.
On December 22, 2017, the U.S. government enacted comprehensive tax legislation under the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code, including but not limited to: (1) reducing the U.S. federal corporate tax rate from 35 percent to 21 percent; (2) requiring companies to pay a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries; (3) generally eliminating U.S. federal income taxes on dividends from foreign subsidiaries; (4) eliminating the corporate alternative minimum tax (“AMT”) and how AMT credits are utilized; (5) the additional limitations on deducting executive compensation under IRC Section 162(m); and (6) changing rules related to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017. Shortly after enactment, implementation guidance was released by the Securities and Exchange Commission that requires a company to reflect the income tax effects of those aspects of the Tax Act for which the accounting under the accounting rules is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete but the company is able to determine a reasonable estimate, it should record a provisional estimate in the financial statements. Further, the implementation guidance also provides for a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete their accounting pursuant to the accounting rules.
Recently Adopted Accounting Standards
In December 2016, the Financial Accounting Standards Board (“FASB”) issued guidance to narrow the definition of a business. This guidance assists entities with evaluating when a set of transferred assets and activities is a business. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, and early adoption is permitted. This guidance must be applied prospectively to transactions occurring within the period of adoption. We adopted this guidance on January 1, 2018. The adoption of this guidance did not have an impact on our financial position, results of operations or cash flows.
In January 2016, the FASB issued guidance on the recognition and measurement of financial instruments. This guidance generally requires equity investments, except those accounted for under the equity method of accounting or those that result in consolidation of the investee, to be measured at fair value with changes in fair value recognized in net income (loss). An entity may elect to measure equity securities that do not have readily determinable fair values and do not qualify for the net asset value per share practical expedient at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The guidance also requires the separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, early adoption is permitted, and the guidance must be applied prospectively to equity investments that exist as of the adoption date. We adopted this guidance, and the February 2018 amendment to this guidance, effective January 1, 2018. The adoption of this guidance did not have any impact on our financial position, results of operations or cash flows.
In May 2014, the FASB issued guidance on revenue from contracts with customers. The guidance states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those products or services. It also states that an entity should recognize as an asset the incremental costs of obtaining a contract that the entity expects to recover and amortize the costs consistent with the transfer to the customer of the products or services to which the asset relates. The guidance requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. We adopted this guidance effective January 1, 2018 using the modified retrospective transition approach applied to all contracts at the date of initial application. We recorded an adjustment of $40.3 million to decrease accumulated deficit as of January 1, 2018 related to the accounting for the cost of sales commissions, primarily related to sales commissions for our Premier Agent and Premier Broker advertising products.
Historically, we expensed these sales commission costs as incurred, but under the new guidance, the cost of certain sales commissions is recorded as a contract cost asset and recognized as an operating expense over the period that we expect to recover the costs.
The amount by which each financial statement line item is affected by the application of this guidance as of and for the year ended December 31, 2018 is as follows (in thousands, except per share data):
 
 
New Guidance
 
Prior Guidance
 
Change
Consolidated Statement of Operations:
 
 
 
 
 
 
Sales and marketing
 
$
552,621

 
$
558,118

 
$
(5,497
)
Total costs and expenses
 
1,462,529

 
1,468,026

 
(5,497
)
Loss from operations
 
(128,975
)
 
(134,472
)
 
5,497

Loss before income taxes
 
(150,960
)
 
(156,457
)
 
5,497

Income tax benefit
 
31,102

 
32,024

 
(922
)
Net loss
 
(119,858
)
 
(124,433
)
 
4,575

Net loss per share — basic and diluted
 
(0.61
)
 
(0.63
)
 
0.02

Consolidated Balance Sheet:
 
 
 
 
 

Contract cost assets
 
45,819

 

 
45,819

Total assets
 
4,291,116

 
4,245,297

 
45,819

Deferred tax liabilities and other long-term liabilities
 
17,474

 
16,552

 
922

Total liabilities
 
1,023,937

 
1,023,015

 
922

Accumulated deficit
 
(671,779
)
 
(716,676
)
 
44,897

Total shareholders’ equity
 
3,267,179

 
3,222,282

 
44,897

Total liabilities and shareholders’ equity
 
$
4,291,116

 
$
4,245,297

 
$
45,819


Recently Issued Accounting Standards Not Yet Adopted
In August 2018, the FASB issued guidance related to a customer’s accounting for implementation costs incurred in hosting arrangements. The guidance aligns the requirements for capitalizing implementation costs incurred in cloud computing arrangements with the requirements for capitalizing costs to develop or obtain internal-use software. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, and early adoption is permitted. This guidance may be applied either retrospectively or prospectively. We expect to adopt this guidance on January 1, 2020. We have not yet determined the impact the adoption of this guidance will have on our financial position, results of operations or cash flows.
In August 2018, the FASB issued guidance related to disclosure requirements for fair value measurements. This guidance removes, modifies and adds disclosures related to fair value measurements. This guidance is effective for interim and annual periods beginning after December 15, 2019, and early adoption is permitted. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim and annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. We expect to adopt this guidance on January 1, 2020. We have not yet determined the impact the adoption of this guidance will have on our financial statement disclosures.
In June 2018, the FASB issued guidance related to contributions received and made. This guidance assists entities with evaluating whether a transfer of assets is considered a contribution or an exchange transaction. This guidance is effective for interim and annual reporting periods beginning after June 15, 2018 for contributions received and after December 15, 2018 for contributions made, and early adoption is permitted. The guidance should be applied on a modified prospective basis, though retrospective application is permitted. We adopted this guidance on January 1, 2019. The adoption of this guidance is not expected to have a material impact on our financial position, results of operations or cash flows.
In February 2018, the FASB issued guidance on income tax accounting related to the Tax Act. This guidance permits a reclassification from accumulated other comprehensive income (loss) to accumulated deficit for the adjustment of deferred taxes due to the reduction of the historical corporate income tax rate to the newly enacted corporate income tax rate under the Tax Act. It also requires certain disclosures regarding these reclassifications. The guidance is effective for interim and annual reporting periods beginning after December 15, 2018, and early adoption is permitted. This guidance must be applied either on a prospective basis in the period of adoption or retrospectively to each period in which the effect of the change in the corporate income tax rate is recognized. We adopted this guidance on January 1, 2019. The adoption of this guidance is not expected to have a material impact on our financial position, results of operations or cash flows.
In March 2017, the FASB issued guidance related to the premium amortization on purchased callable debt securities. This guidance shortens the amortization period for certain callable debt securities purchased at a premium by requiring that the premium be amortized to the earliest call date. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, and early adoption is permitted. This guidance must be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. We adopted this guidance on January 1, 2019. The adoption of this guidance is not expected to have a material impact on our financial position, results of operations or cash flows.
In June 2016, the FASB issued guidance on the measurement of credit losses on financial instruments. This guidance requires the use of an expected loss impairment model for instruments measured at amortized cost. For available-for-sale debt securities, an entity is required to recognize credit losses through an allowance for credit losses rather than as a write-down. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, and early adoption is permitted for interim and annual reporting periods beginning after December 15, 2018. The adoption of this guidance requires a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. We expect to adopt this guidance on January 1, 2020. We have not yet determined the impact the adoption of this guidance will have on our financial position, results of operations or cash flows.
In February 2016, the FASB issued guidance on leases. This guidance requires the recognition of a right-of-use asset and lease liability on the balance sheet for all leases. This guidance also requires more detailed disclosures to enable users of financial statements to understand the amount, timing, and uncertainty of cash flows arising from leases. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018. In July 2018, the FASB issued certain targeted improvements to the accounting and disclosure requirements for leases, including an additional optional transition method that allows entities to initially apply the new standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption without restating prior periods. When adopting the lease guidance, an entity may elect a practical expedient package, under which it need not reassess (a) whether any expired or existing contracts are or contain leases; (b) the lease classification for any expired or existing leases; and (c) initial direct costs for any existing leases. These three practical expedients must be elected as a package and must be consistently applied to all existing leases at the date of adoption. We adopted the new guidance on leases on January 1, 2019 using the optional transition method and electing to adopt the practical expedient package. Under this approach, we will not restate the prior financial statements presented. Based on our lease portfolio as of December 31, 2018, we anticipate recording on our consolidated balance sheet right-of-use assets of approximately $90 million as well as operating lease liabilities of approximately $115 million with no material impact to our consolidated statements of operations or cash flows.
v3.10.0.1
Fair Value Measurements
12 Months Ended
Dec. 31, 2018
Fair Value Disclosures [Abstract]  
Fair Value Measurements Fair Value Measurements
Accounting standards define fair value as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. The standards also establish a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value:
 
Level 1—Quoted prices in active markets for identical assets or liabilities.
Level 2—Assets and liabilities valued based on observable market data for similar instruments, such as quoted prices for similar assets or liabilities.
Level 3—Unobservable inputs that are supported by little or no market activity; instruments valued based on the best available data, some of which is internally developed, and considers risk premiums that a market participant would require.
We applied the following methods and assumptions in estimating our fair value measurements:
Cash equivalents—The fair value measurement of money market funds is based on quoted market prices in active markets. The fair value measurement of corporate notes and bonds, commercial paper, U.S. government agency securities and certificates of deposit is based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means.
Short-term investments—The fair value measurement of our short-term investments is based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means.
Restricted cash—The carrying value of restricted cash approximates fair value due to the short period of time amounts borrowed on the Revolving Credit Facility (see Note 14) are outstanding. Further, the carrying value of restricted cash related to escrow amounts held as part of the mortgage originations business also approximates fair value due to the short period of time amounts are held in escrow before they are transferred to the appropriate party, typically a home seller or bank.
Mortgage loans held for sale—The fair value of mortgage loans held for sale is generally calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics.
Interest rate lock commitments—The fair value of interest rate lock commitments is calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics. Any expired commitments are excluded from the fair value measurement. We generally only issue IRLCs for products that meet specific purchaser guidelines. Since not all IRLCs will become closed loans, we adjust our fair value measurements for the estimated amount of IRLCs that will not close.
Forward contracts—The fair value of mandatory loan sales commitments and derivative instruments such as forward sales of MBS that are utilized as hedging instruments are calculated by reference to quoted prices for similar assets.
The following tables present the balances of assets measured at fair value on a recurring basis, by level within the fair value hierarchy, as of the dates presented (in thousands):
 
December 31, 2018
 
Total
 
Level 1
 
Level 2
Cash equivalents:
 
 
 
 
 
Money market funds
$
541,575

 
$
541,575

 
$

Commercial paper
3,999

 

 
3,999

Short-term investments:
 
 
 
 
 
U.S. government agency securities
646,496

 

 
646,496

Corporate notes and bonds
112,933

 

 
112,933

Commercial paper
85,506

 

 
85,506

Municipal securities
39,306

 

 
39,306

Foreign government securities
14,915

 

 
14,915

Certificates of deposit
4,711

 

 
4,711

Mortgage origination-related:
 
 
 
 
 
Mortgage loans held for sale
35,409

 

 
35,409

Interest rate lock commitments
847

 

 
847

Forward contracts
(125
)
 

 
(125
)
Total
$
1,485,572

 
$
541,575

 
$
943,997

 
December 31, 2017
 
Total
 
Level 1
 
Level 2
Cash equivalents:
 
 
 
 
 
Money market funds
$
233,508

 
$
233,508

 
$

Corporate notes and bonds
6,199

 

 
6,199

Commercial paper
3,987

 

 
3,987

U.S. government agency securities
1,748

 

 
1,748

Certificates of deposit
249

 

 
249

Short-term investments:
 
 
 
 
 
U.S. government agency securities
298,758

 

 
298,758

Corporate notes and bonds
44,607

 

 
44,607

Commercial paper
39,325

 

 
39,325

Municipal securities
11,459

 

 
11,459

Certificates of deposit
10,297

 

 
10,297

Foreign government securities
5,998

 

 
5,998

Total
$
656,135

 
$
233,508

 
$
422,627


At December 31, 2018, the notional amounts of the hedging instruments related to our mortgage loans held for sale were $26.7 million and $28.8 million for our interest rate lock commitments and forward contracts, respectively.
See Note 14 for the carrying amount and estimated fair value of the Company’s Convertible Senior Notes due in 2023, Convertible Senior Notes due in 2021 and Trulia’s Convertible Senior Notes due in 2020.
We did not have any Level 3 assets as of December 31, 2018 or 2017. There were no material liabilities measured at fair value as of December 31, 2018 or 2017.
v3.10.0.1
Cash and Cash Equivalents, Short-term Investments and Restricted Cash
12 Months Ended
Dec. 31, 2018
Cash and Cash Equivalents [Abstract]  
Cash and Cash Equivalents, Short-term Investments and Restricted Cash Cash and Cash Equivalents, Short-term Investments and Restricted Cash
The following tables present the amortized cost, gross unrealized gains and losses and estimated fair market value of our cash and cash equivalents, available-for-sale investments and restricted cash as of the dates presented (in thousands):
 
December 31, 2018
 
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Estimated
Fair
Market
Value
Cash
$
105,484

 
$

 
$

 
$
105,484

Cash equivalents:
 
 
 
 
 
 
 
Money market funds
541,575

 

 

 
541,575

Commercial paper
3,999

 

 

 
3,999

Short-term investments:
 
 
 
 
 
 
 
U.S. government agency securities
647,266

 
51

 
(821
)
 
646,496

Corporate notes and bonds
113,109

 
1

 
(177
)
 
112,933

Commercial paper
85,506

 

 

 
85,506

Municipal securities
39,316

 
23

 
(33
)
 
39,306

Foreign government securities
14,929

 

 
(14
)
 
14,915

Certificates of deposit
4,711

 
1

 
(1
)
 
4,711

Restricted cash
12,385

 

 

 
12,385

Total
$
1,568,280

 
$
76

 
$
(1,046
)
 
$
1,567,310

 
December 31, 2017
 
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Estimated
Fair
Market
Value
Cash
$
106,404

 
$

 
$

 
$
106,404

Cash equivalents:
 
 
 
 
 
 
 
Money market funds
233,508

 

 

 
233,508

Corporate notes and bonds
6,200

 

 
(1
)
 
6,199

Commercial paper
3,987

 

 

 
3,987

U.S. government agency securities
1,748

 

 

 
1,748

Certificates of deposit
249

 

 

 
249

Short-term investments:
 
 
 
 
 
 
 
U.S. government agency securities
299,814

 

 
(1,056
)
 
298,758

Corporate notes and bonds
44,661

 
1

 
(55
)
 
44,607

Commercial paper
39,325

 

 

 
39,325

Municipal securities
11,494

 

 
(35
)
 
11,459

Certificates of deposit
10,296

 
2

 
(1
)
 
10,297

Foreign government securities
6,000

 

 
(2
)
 
5,998

Total
$
763,686

 
$
3

 
$
(1,150
)
 
$
762,539


The following table presents available-for-sale investments by contractual maturity date as of December 31, 2018 (in thousands):
 
Amortized
Cost
 
Estimated Fair Market Value
Due in one year or less
$
801,828

 
$
800,827

Due after one year through two years
103,009

 
103,040

Total
$
904,837

 
$
903,867

v3.10.0.1
Accounts Receivable, Net
12 Months Ended
Dec. 31, 2018
Receivables [Abstract]  
Accounts Receivable, Net Accounts Receivable, Net
The following table presents the detail of accounts receivable as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Accounts receivable
$
61,134

 
$
51,334

Unbilled accounts receivable
9,787

 
8,403

Less: allowance for doubtful accounts
(4,838
)
 
(5,341
)
Accounts receivable, net
$
66,083

 
$
54,396


The following table presents the changes in the allowance for doubtful accounts for the periods presented (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Allowance for doubtful accounts:
 
 
 
 
 
Balance, beginning of period
$
5,341

 
$
1,337

 
$
3,378

Additions charged to expense
869

 
7,349

 
2,681

Less: write-offs, net of recoveries and other adjustments
(1,372
)
 
(3,345
)
 
(4,722
)
Balance, end of period
$
4,838

 
$
5,341

 
$
1,337

v3.10.0.1
Inventory
12 Months Ended
Dec. 31, 2018
Inventory Disclosure [Abstract]  
Inventory Inventory
The components of inventory, net of applicable lower of cost or net realizable value write-downs, were as follows for the periods presented (in thousands):
 
December 31,
 
2018
 
2017
Work-in-progress
$
45,943

 
$

Finished goods
116,886

 

Inventory
$
162,829

 
$


We have not recorded any inventory write-downs for the years ended December 31, 2018 and 2017.
v3.10.0.1
Contract Cost Assets
12 Months Ended
Dec. 31, 2018
Revenue from Contract with Customer [Abstract]  
Contract Cost Assets Contract Cost AssetsAs of December 31, 2018, we had $45.8 million of contract cost assets. During the year ended December 31, 2018, we recorded no impairment losses to contract cost assets. During the year ended December 31, 2018, we recorded $36.0 million of amortization expense related to contract cost assets.Deferred Revenue
The following table presents the change in deferred revenue for the period presented (in thousands):
 
Year Ended December 31, 2018
Balance as of January 1, 2018
$
31,918

Deferral of revenue
982,647

Less: Revenue recognized
(980,485
)
Balance as of December 31, 2018
$
34,080


During the year ended December 31, 2018, we recognized as revenue a total of $28.8 million pertaining to amounts that were recorded in deferred revenue as of December 31, 2017.
v3.10.0.1
Property and Equipment, Net
12 Months Ended
Dec. 31, 2018
Property, Plant and Equipment [Abstract]  
Property and Equipment, Net Property and Equipment, Net
The following table presents the detail of property and equipment as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Website development costs
$
149,891

 
$
130,072

Computer equipment
22,477

 
30,071

Leasehold improvements
65,012

 
47,321

Construction-in-progress
29,037

 
28,150

Office equipment, furniture and fixtures
39,510

 
22,887

Property and equipment
305,927

 
258,501

Less: accumulated amortization and depreciation
(170,755
)
 
(146,230
)
Property and equipment, net
$
135,172

 
$
112,271


We recorded depreciation expense related to property and equipment (other than website development costs) of $19.5 million, $15.6 million and $13.5 million, respectively, during the years ended December 31, 2018, 2017 and 2016.
We capitalized $34.1 million, $49.9 million and $49.5 million, respectively, in website development costs during the years ended December 31, 2018, 2017 and 2016. Amortization expense for website development costs included in technology and development expenses was $28.6 million, $40.0 million and $40.0 million, respectively, for the years ended December 31, 2018, 2017 and 2016.
v3.10.0.1
Acquisitions and Equity Investments
12 Months Ended
Dec. 31, 2018
Business Combinations [Abstract]  
Acquisitions and Equity Investments Acquisitions and Equity Investments
Acquisition of Mortgage Lenders of America
On October 31, 2018, Zillow Group’s wholly owned subsidiary, ZGM Holdco, Inc., acquired the outstanding equity of Mortgage Lenders of America, L.L.C., a national mortgage lender headquartered in Overland Park, Kansas for approximately $66.7 million in cash.
Our acquisition of MLOA has been accounted for as a business combination, and assets acquired and liabilities assumed were recorded at their estimated fair values as of October 31, 2018. Goodwill, which represents the expected synergies from combining the acquired assets and the operations of the acquirer, as well as intangible assets that do not qualify for separate recognition, is measured as of the acquisition date as the excess of consideration transferred, which is also measured at fair value, and the net of the fair values of the assets acquired and the liabilities assumed as of the acquisition date. The goodwill recognized in conjunction with this business combination has been allocated to our IMT segment.
The total purchase price has been allocated to the assets acquired and liabilities assumed, including identifiable intangible assets, based on their respective fair values at the acquisition date. Based upon the fair values determined by us, in which we considered or relied in part upon a valuation report of a third-party expert, the total purchase price was allocated as follows (in thousands):
Cash and cash equivalents
$
10,796

Restricted cash
753

Mortgage loans available for sale
34,248

Property, plant and equipment
1,315

Intangible assets
2,600

Goodwill
53,831

Other acquired assets
3,079

Accounts payable
(1,953
)
Accrued expenses
(2,591
)
Warehouse lines of credit
(32,536
)
Other assumed liabilities
(2,855
)
Total purchase price
$
66,687


Acquisition-related costs incurred, which primarily included legal, accounting, regulatory and other external costs directly related to the acquisition, are included within Acquisition-related costs within our consolidated statements of operations and were expensed as incurred.
The results of operations related to the acquisition of MLOA have been included in our consolidated financial statements since the date of acquisition, and are not significant. On an unaudited pro forma basis, revenue would have been approximately 3.0% higher for the year ended December 31, 2018 and 5.0% higher for the year-ended December 31, 2017 if the acquisition would have been consummated as of January 1, 2017. Unaudited pro forma earnings information has not been presented as the effects were not material to our consolidated financial statements.
Acquisition of New Home Feed
On September 6, 2017, Zillow, Inc. acquired New Home Feed, Inc. (formerly known as Graphic Language, Inc.), a California corporation which operates the New Home Feed business, pursuant to an Agreement and Plan of Merger for an immaterial amount. New Home Feed is a listing management technology that allows builders to input, manage and syndicate their listings across Zillow Group and partner sites. Our acquisition of New Home Feed has been accounted for as a business combination, and assets acquired and liabilities assumed were recorded at their estimated fair values as of September 6, 2017. We acquired goodwill of $3.6 million and an identifiable intangible asset of $1.9 million.
Acquisition-related costs incurred related to the acquisition of New Home Feed, which primarily included legal and accounting fees and other external costs directly related to the acquisition, were expensed as incurred and were not material.
The results of operations related to the acquisition of New Home Feed have been included in our consolidated financial statements since the date of acquisition and are not significant. Pro forma financial information for the acquisition accounted for as a business combination has not been presented, as the effects were not material to our consolidated financial statements.
Acquisition of Hamptons Real Estate Online
On January 11, 2017, Zillow, Inc. acquired substantially all of the operating assets of RealNet Solutions, Inc., a New York corporation, RealNetDB, LLC, a New York limited liability company, Hamptons Real Estate Online, Inc., a New York corporation, and HREO.com, LLC, a New York limited liability company (collectively, “HREO”), pursuant to an Asset Purchase Agreement entered into by Zillow, Inc., HREO, each of the equity owners of HREO, and an individual acting as representative of the HREO equity holders. HREO is a Hamptons-focused real estate portal which provides buyers and renters with a specialized search experience and access to the area’s most comprehensive for-sale, for-rent, and vacant land listings. HREO’s listing entry and distribution software, RealNet and Open RealNet Exchange, provides real estate professionals with tools to manage and market their listings. Our acquisition of HREO has been accounted for as a business combination, and assets acquired and liabilities assumed were recorded at their estimated fair values as of January 11, 2017. We acquired goodwill of $4.0 million, identifiable intangible assets of $2.1 million and net liabilities of approximately $0.1 million.
Acquisition-related costs incurred related to the acquisition of HREO, which primarily included legal and accounting fees and other external costs directly related to the acquisition, were expensed as incurred and were not material.
The results of operations related to the acquisition of HREO have been included in our consolidated financial statements since the date of acquisition and are not significant. Pro forma financial information for the acquisition accounted for as a business combination has not been presented, as the effects were not material to our consolidated financial statements.
Acquisition of Bridge Interactive Group
In July 2016, Zillow, Inc., Bridge Interactive Group, LLC, a Georgia limited liability company (“Bridge Interactive”), each of the members of Bridge Interactive, and an individual acting as the seller representative, entered into a Securities Purchase Agreement pursuant to which Zillow, Inc. acquired all of the outstanding ownership interests of Bridge Interactive on August 1, 2016. Bridge Interactive is a creator of broker and multiple listing service (MLS) back-office software. Our acquisition of Bridge Interactive has been accounted for as a business combination, and assets acquired and liabilities assumed were recorded at their estimated fair values as of August 1, 2016.
Acquisition-related costs incurred, which primarily included legal and accounting fees and other external costs directly related to the acquisition, were expensed as incurred and were not material.
The results of operations related to the acquisition of Bridge Interactive have been included in our consolidated financial statements since the date of acquisition and are not significant. Pro forma financial information for the acquisition accounted for as a business combination has not been presented, as the effects were not material to our consolidated financial statements.
Acquisition of Naked Apartments
In February 2016, Zillow, Inc., Nectarine Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Zillow, Inc. (“Merger Sub”), Naked Apartments, Inc., a Delaware corporation (“Naked Apartments”), and an individual acting as the stockholder representative, entered into an Agreement and Plan of Merger (the “Naked Apartments Merger Agreement”), pursuant to which Zillow, Inc. acquired Naked Apartments on February 22, 2016 for approximately $13.2 million in cash. Under the terms and subject to the conditions of the Naked Apartments Merger Agreement, Merger Sub merged with and into Naked Apartments, with Naked Apartments remaining as the surviving company and a wholly owned subsidiary of Zillow, Inc. Naked Apartments is New York City’s largest rentals-only platform.
Our acquisition of Naked Apartments has been accounted for as a business combination, and assets acquired and liabilities assumed were recorded at their estimated fair values as of February 22, 2016. Goodwill, which represents the expected synergies from combining the acquired assets and the operations of the acquirer, as well as intangible assets that do not qualify for separate recognition, is measured as of the acquisition date as the excess of consideration transferred, which is also measured at fair value, and the net of the fair values of the assets acquired and the liabilities assumed as of the acquisition date.
The total purchase price has been allocated to the assets acquired and liabilities assumed, including identifiable intangible assets, based on their respective fair values at the acquisition date. Based upon the fair values determined by us, in which we considered or relied in part upon a valuation report of a third-party expert, the total purchase price was allocated as follows (in thousands):
Current assets
$
371

Identifiable intangible assets
3,700

Goodwill
10,610

Current liabilities
(101
)
Deferred tax liabilities
(1,416
)
Total purchase price
$
13,164


Acquisition-related costs incurred, which primarily included legal and accounting fees and other external costs directly related to the acquisition, were expensed as incurred and were not material.
The results of operations related to the acquisition of Naked Apartments have been included in our consolidated financial statements since the date of acquisition and are not significant. Pro forma financial information for the acquisition accounted for as a business combination has not been presented, as the effects were not material to our consolidated financial statements.
Equity Investments
In June 2017, we purchased an equity interest in a privately held corporation for approximately $10.0 million.
In October 2016, we purchased a 10% equity interest in a privately held variable interest entity within the real estate industry for $10.0 million. The entity is financed through its business operations. We are not the primary beneficiary of the entity, as we do not direct the activities that most significantly impact the entity’s economic performance. Therefore, we do not consolidate the entity. Our maximum exposure to loss is $10.0 million, the carrying amount of the investment as of December 31, 2018.
These investments are equity securities without readily determinable fair values which we account for at cost minus any impairment, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same issuer. During the year ended December 31, 2018, we recognized a non-cash impairment charge of $10.0 million related to our June 2017 investment. The impairment charge is included in Impairment costs within our consolidated statements of operations. During the third quarter of 2018, in connection with our quarterly qualitative assessment of this investment for impairment indicators, we identified factors that led us to conclude that the investment was impaired and the fair value of the investment was less than the carrying value. The most significant of such factors was related to the business prospects of the investee. Accordingly, we performed an analysis to determine the fair value of the investment and concluded that our best estimate of its fair value was $0.0 million. This is considered a Level 3 measurement under the fair value hierarchy.
There has been no impairment or upward or downward adjustments for our October 2016 equity investment as of December 31, 2018 that would impact the carrying amount of the investment. The October 2016 investment is classified within other assets in the consolidated balance sheet.
v3.10.0.1
Goodwill
12 Months Ended
Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill Goodwill
The goodwill balance as of December 31, 2018 and 2017 is fully attributable to our IMT segment. The following table presents the change in goodwill from December 31, 2017 through December 31, 2018 (in thousands):
Balance as of December 31, 2017
$
1,931,076

Goodwill recorded in connection with acquisition of MLOA
53,831

Balance as of December 31, 2018
$
1,984,907


The goodwill recorded in connection with the acquisition of MLOA, which includes intangible assets that do not qualify for separate recognition, is not deductible for tax purposes.
v3.10.0.1
Intangible Assets
12 Months Ended
Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]  
Intangible Assets Intangible Assets
The following tables present the detail of intangible assets subject to amortization as of the dates presented (in thousands):
 
December 31, 2018
 
Cost
 
Accumulated
Amortization
 
Net
Purchased content
$
42,110

 
$
(30,477
)
 
$
11,633

Software
24,296

 
(13,925
)
 
10,371

Customer relationships
103,900

 
(60,733
)
 
43,167

Developed technology
111,980

 
(72,788
)
 
39,192

Trade names and trademarks
4,900

 
(4,683
)
 
217

MLOA lender licenses
400

 
(17
)
 
383

Intangibles-in-progress
2,941

 

 
2,941

Total
$
290,527

 
$
(182,623
)
 
$
107,904

 
December 31, 2017
 
Cost
 
Accumulated
Amortization
 
Net
Purchased content
$
35,260

 
$
(20,480
)
 
$
14,780

Software
18,957

 
(8,899
)
 
10,058

Customer relationships
103,900

 
(46,365
)
 
57,535

Developed technology
113,380

 
(56,664
)
 
56,716

Trade names and trademarks
4,900

 
(3,943
)
 
957

Advertising relationships
9,000

 
(8,525
)
 
475

Intangibles-in-progress
2,190

 

 
2,190

Total
$
287,587

 
$
(144,876
)
 
$
142,711


Amortization expense recorded for intangible assets for the years ended December 31, 2018, 2017 and 2016 was $50.8 million, $54.3 million and $47.0 million, respectively, and these amounts are included in technology and development expenses.
Estimated future amortization expense for intangible assets, including amortization related to future commitments (see Note 19), as of December 31, 2018 is as follows (in thousands):
2019
$
42,648

2020
39,420

2021
33,908

2022
5,480

2023
373

Total future amortization expense
$
121,829


We have an indefinite-lived intangible asset that we recorded in connection with our February 2015 acquisition of Trulia for Trulia’s trade names and trademarks that is not subject to amortization. The carrying value of the Trulia trade names and trademarks intangible asset was $108.0 million and $177.0 million, respectively, as of December 31, 2018 and 2017.
During the year ended December 31, 2018, we recognized a non-cash impairment charge of $69.0 million related to our indefinite-lived Trulia trade names and trademarks intangible asset. The impairment charge is included in Impairment costs within our IMT segment. In connection with our annual budgeting process that was substantially completed during the three months ended December 31, 2018, we identified factors that led us to conclude it was more likely than not that the $177.0 million carrying value of the asset exceeded its fair value. The most significant of such factors was a shortfall in projected revenue related to the Trulia brand compared to projections at the time the intangible asset was remeasured as of October 1, 2017. Accordingly, with the assistance of a third-party valuation specialist, we performed a quantitative analysis to determine the fair value of the intangible asset and concluded that our best estimate of its fair value was $108.0 million. The valuation was prepared using an income approach based on the relief-from-royalty method and relied on inputs with unobservable market
prices including the assumed revenue growth rates, royalty rate, discount rate, and estimated tax rate, and therefore is considered a Level 3 measurement under the fair value hierarchy. In connection with this impairment analysis, we evaluated our planned future use of the Trulia trade names and trademarks intangible asset and concluded that it remains appropriate to consider this asset to have an indefinite life.
During the year ended December 31, 2017, we recognized a non-cash impairment charge of $174.0 million related to our indefinite-lived Trulia trade names and trademarks intangible asset. The impairment charge is included in Impairment costs within our consolidated statements of operations. In connection with our qualitative assessment of the recoverability of this asset during our annual impairment test as of October 1, 2017, we identified factors that led us to conclude it was more likely than not that the $351.0 million carrying value of the asset exceeded its fair value. The most significant of such factors was a shortfall in projected revenue related to the Trulia brand compared to projections at the time the intangible asset was initially recorded in February 2015. Accordingly, with the assistance of a third-party valuation specialist, we performed a quantitative analysis to determine the fair value of the intangible asset and concluded that our best estimate of its fair value was $177.0 million. The valuation was prepared using an income approach based on the relief-from-royalty method and relied on inputs with unobservable market prices including the assumed revenue growth rates, royalty rate, discount rate, and estimated tax rate, and therefore is considered a Level 3 measurement under the fair value hierarchy. In connection with this impairment analysis, we evaluated our planned future use of the Trulia trade names and trademarks intangible asset and concluded that it remains appropriate to consider this asset to have an indefinite life.
v3.10.0.1
Accrued Expenses and Other Current Liabilities
12 Months Ended
Dec. 31, 2018
Payables and Accruals [Abstract]  
Accrued Expenses and Other Current Liabilities Accrued Expenses and Other Current Liabilities
The following table presents the detail of accrued expenses and other current liabilities as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Accrued marketing and advertising
$
18,559

 
$
17,180

Accrued purchased content
4,256

 
5,984

Accrued estimated legal liabilities and legal fees
7,305

 
9,052

Merger consideration payable to former stockholders of certain acquired entities
5,904

 
5,904

Other accrued expenses and other current liabilities
27,077

 
23,253

Total accrued expenses and other current liabilities
$
63,101

 
$
61,373

v3.10.0.1
Deferred Revenue
12 Months Ended
Dec. 31, 2018
Revenue from Contract with Customer [Abstract]  
Deferred Revenue Contract Cost AssetsAs of December 31, 2018, we had $45.8 million of contract cost assets. During the year ended December 31, 2018, we recorded no impairment losses to contract cost assets. During the year ended December 31, 2018, we recorded $36.0 million of amortization expense related to contract cost assets.Deferred Revenue
The following table presents the change in deferred revenue for the period presented (in thousands):
 
Year Ended December 31, 2018
Balance as of January 1, 2018
$
31,918

Deferral of revenue
982,647

Less: Revenue recognized
(980,485
)
Balance as of December 31, 2018
$
34,080


During the year ended December 31, 2018, we recognized as revenue a total of $28.8 million pertaining to amounts that were recorded in deferred revenue as of December 31, 2017.
v3.10.0.1
Debt
12 Months Ended
Dec. 31, 2018
Debt Disclosure [Abstract]  
Debt Debt
Revolving Credit Facility
On July 31, 2018, certain wholly owned subsidiaries of Zillow Group entered into a revolving credit agreement with Credit Suisse AG, Cayman Islands Branch, as the directing lender, and certain other parties thereto (the “Revolving Credit Facility”). The Revolving Credit Facility initially provided for a maximum borrowing capacity of $250.0 million, and this borrowing capacity was increased to $500.0 million effective December 31, 2018 (the “Maximum Amount”) and has a current borrowing capacity of $126.7 million as of December 31, 2018, which amount may be increased up to the Maximum Amount
subject to the satisfaction of certain conditions, through a non-recourse credit facility secured by a pledge of the equity of certain Zillow Group subsidiaries that purchase and sell select residential properties through Zillow Offers. In certain circumstances Zillow Group may be obligated to fund some or all of the payment obligations under the Revolving Credit Facility. Zillow Group formed certain special purpose entities to effectuate the transactions contemplated by the agreement underlying the Revolving Credit Facility. Each special purpose entity is a wholly owned subsidiary of Zillow Group and a separate legal entity, and neither the assets nor credit of any such entity are available to satisfy the debts and other obligations of any affiliate or other entity.
The Revolving Credit Facility has an initial term of one year which may be extended for up to two additional years subject to agreement by the directing lender. The Revolving Credit Facility includes customary representations and warranties, covenants (including financial covenants applicable to Zillow Group), and provisions regarding events of default. As of December 31, 2018, Zillow Group was in compliance with all financial covenants and no event of default had occurred. Availability of funds under the Revolving Credit Facility is limited by a formula equal to the lower of 85% of the aggregate acquisition cost of financed residential properties or 85% of the aggregate market value, which for each residential property is the sum of the value established by an independent broker-pricing opinion and renovation costs paid.
Pursuant to the terms of the Revolving Credit Facility, we are required to establish, maintain, and in certain circumstances fund, certain specified reserve accounts. These reserve accounts include, but are not limited to, interest reserves, insurance, tax reserves, renovation cost reserves and special reserves. The credit facility reserve accounts and the collection account into which funds are deposited upon the resale of financed residential properties, which funds are used to repay amounts borrowed on the Revolving Credit Facility, are under the sole control of Credit Suisse AG, New York Branch, as defined in the agreement governing the Revolving Credit Facility. Amounts funded to these reserve accounts and the collection account have been classified within our consolidated balance sheets as restricted cash. Borrowings on our Revolving Credit Facility bear interest at the one-month London Interbank Offered Rate (“LIBOR”) plus the applicable margin, as defined in the credit agreement governing the Revolving Credit Facility. We are also required to pay a funding fee for each financed residential property and certain other fees to certain other parties to the agreement. Interest, funding fees and other fees, including the amortization of deferred issuance costs, are classified within interest expense in our consolidated statements of operations.
As of December 31, 2018, we have outstanding $116.7 million of borrowings on the Revolving Credit Facility. The facility has a maximum borrowing capacity of $500.0 million with a current borrowing capacity of $126.7 million. Approximately $383.3 million is available for future borrowings. The weighted average interest rate related to the Revolving Credit Facility from July 31, 2018 through December 31, 2018 was 5.86%.
Warehouse Lines of Credit
As part of the acquisition of MLOA, Zillow Group acquired two warehouse lines of credit. Each line of credit provides for a current and maximum borrowing capacity of $50.0 million, or $100.0 million in total. The lines of credit mature on July 15, 2019 and March 31, 2019 and include customary representations and warranties, covenants and provisions regarding events of default. As of December 31, 2018, Zillow Group was in compliance with all financial covenants and no event of default had occurred. Availability under the lines of credit is limited depending on the types of loans originated. Borrowings on the lines of credit bear interest at either the one-month LIBOR or the daily adjusting LIBOR, plus an applicable margin, as defined in the credit agreements governing the warehouse lines of credit. The weighted average interest rates on each of the lines of credit from the acquisition of MLOA through December 31, 2018 were 4.88% and 4.73%.
Convertible Senior Notes due in 2023
On July 3, 2018, Zillow Group issued $373.8 million aggregate principal amount of Convertible Senior Notes due 2023 (the “2023 Notes”), which includes $48.8 million principal amount of 2023 Notes sold pursuant to the underwriters’ option to purchase additional 2023 Notes. The 2023 Notes bear interest at a fixed rate of 1.50% per year, payable semi-annually in arrears on January 1 and July 1 of each year, beginning on January 1, 2019. The 2023 Notes are convertible into cash, shares of Class C capital stock or a combination thereof, at our election. The 2023 Notes will mature on July 1, 2023, unless earlier repurchased, redeemed, or converted in accordance with their terms.
The net proceeds from the issuance of the 2023 Notes were approximately $364.0 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. We used approximately $29.4 million of the net proceeds from the issuance of the 2023 Notes to pay the cost of the Capped Call Confirmations described below. The Company intends to use the remainder of the net proceeds for general corporate purposes.
Prior to the close of business on the business day immediately preceding April 1, 2023, the 2023 Notes are convertible at the option of the holders only under certain conditions. On or after April 1, 2023, until the close of business on the second
scheduled trading day immediately preceding the maturity date, holders may convert their 2023 Notes at their option at the conversion rate then in effect, irrespective of these conditions. The Company may settle conversions of the 2023 Notes by paying or delivering, as the case may be, cash, shares of the Company’s Class C capital stock, or a combination of cash and shares of Class C capital stock, at its election. The conversion rate will initially be 12.7592 shares of Class C capital stock per $1,000 principal amount of 2023 Notes (equivalent to an initial conversion price of approximately $78.37 per share of Class C capital stock). The conversion rate is subject to customary adjustments upon the occurrence of certain events. The Company may redeem for cash all or part of the 2023 Notes, at its option, on or after July 6, 2021, under certain circumstances at a redemption price equal to 100% of the principal amount of the 2023 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date (as defined in the indenture governing the 2023 Notes). The conversion option does not meet the criteria for separate accounting as a derivative as it is indexed to our own stock.
If the Company undergoes a fundamental change (as defined in the indenture governing the 2023 Notes), holders may require the Company to repurchase for cash all or part of their 2023 Notes at a repurchase price equal to 100% of the principal amount of the 2023 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date (as defined in the indenture governing the 2023 Notes). In addition, if certain fundamental changes occur, the Company may be required in certain circumstances to increase the conversion rate for any Notes converted in connection with such fundamental changes by a specified number of shares of its Class C capital stock. Certain events are also considered “Events of Default,” which may result in the acceleration of the maturity of the 2023 Notes, as described in the indenture governing the 2023 Notes. There are no financial covenants associated with the 2023 Notes.
We may not redeem the 2023 Notes prior to July 6, 2021. We may redeem for cash all or any portion of the 2023 Notes, at our option, in whole or in part on or after July 6, 2021 if the last reported sale price per share of our Class C capital stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period.
In accounting for the issuance of the 2023 Notes, the Company separated the 2023 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The carrying amount of the equity component, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the 2023 Notes. The difference between the principal amount of the 2023 Notes and the liability component represents the debt discount, which is recorded as a direct deduction from the related debt liability in the consolidated balance sheet and amortized to interest expense using the effective interest method over the term of the 2023 Notes. The equity component of the 2023 Notes of approximately $78.6 million is included in additional paid-in capital in the consolidated balance sheet and is not remeasured as long as it continues to meet the conditions for equity classification.
Interest expense related to the 2023 Notes for the year ended December 31, 2018 was $10.1 million, which is comprised of approximately $7.3 million related to the amortization of debt discount and debt issuance costs and $2.8 million for the contractual coupon interest.
The effective interest rate on the liability component of the 2023 Notes for the year ended December 31, 2018 is 6.99%. Accrued interest related to the 2023 Notes as of December 31, 2018 was not material. Accrued interest is recorded in accrued expenses and other current liabilities in our consolidated balance sheet.
The following table presents the outstanding principal amount and carrying value of the 2023 Notes as of the date presented (in thousands):
 
Outstanding
Principal
Amount
 
Unamortized
Debt Discount
and Debt
Issuance Costs
 
Carrying
Value
December 31, 2018
$
373,750

 
$
(79,012
)
 
$
294,738


As of December 31, 2018, the unamortized debt discount and debt issuance costs for the 2023 Notes will be amortized to interest expense over a remaining period of approximately 54 months.
The estimated fair value of the 2023 Notes was $321.9 million as of December 31, 2018. The estimated fair value of the 2023 Notes was determined through consideration of quoted market prices. The fair value is classified as Level 3 due to the limited trading activity for the 2023 Notes.
The Capped Call Confirmations are expected generally to reduce the potential dilution of our Class C capital stock upon any conversion of 2023 Notes and/or offset the cash payments the Company is required to make in excess of the principal amount of the 2023 Notes in the event that the market price of the Class C capital stock is greater than the strike price of the Capped Call Confirmations (which initially corresponds to the initial conversion price of the 2023 Notes and is subject to certain adjustments under the terms of the Capped Call Confirmations), with such reduction and/or offset subject to a cap based on the cap price of the Capped Call Confirmations. The Capped Call Confirmations have an initial cap price of $105.45 per share, which represents a premium of approximately 85% over the public offering price of the Company’s Class C capital stock in the concurrent share offering of $57.00, and is subject to certain adjustments under the terms of the Capped Call Confirmations. The Capped Call Confirmations will cover, subject to anti-dilution adjustments substantially similar to the 2023 Notes, the number of shares of Class C capital stock that will underlie the 2023 Notes. The Capped Call Confirmations do not meet the criteria for separate accounting as a derivative as they are indexed to our own stock. The premiums paid for the Capped Call Confirmations have been included as a net reduction to additional paid-in-capital within shareholders’ equity.
Convertible Senior Notes due in 2021
On December 12, 2016, Zillow Group issued $460.0 million aggregate principal amount of 2.00% Convertible Senior Notes due 2021 (the “2021 Notes”), which amount includes the exercise in full of the $60.0 million over-allotment option, to Citigroup Global Markets Inc. as the initial purchaser of the 2021 Notes in a private offering to the initial purchaser in reliance on the exemption from the registration requirements provided by Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”) for resale to qualified institutional buyers as defined in, and pursuant to, Rule 144A under the Securities Act. The 2021 Notes bear interest at a fixed rate of 2.00% per year, payable semi-annually in arrears on June 1 and December 1 of each year. The 2021 Notes are convertible into cash, shares of our Class C capital stock or a combination thereof, at the Company’s election. The 2021 Notes will mature on December 1, 2021, unless earlier repurchased, redeemed, or converted in accordance with their terms.
The net proceeds from the issuance of the 2021 Notes were approximately $447.8 million, after deducting fees and expenses. The Company used approximately $370.2 million of the net proceeds from the issuance of the 2021 Notes to repurchase a portion of the outstanding 2020 Notes (see additional information below under “Trulia’s Convertible Senior Notes due 2020”) in privately negotiated transactions. In addition, the Company used approximately $36.6 million of the net proceeds from the issuance of the 2021 Notes to pay the cost of the capped call transactions with the initial purchaser of the 2021 Notes and two additional financial institutions (“Capped Call Confirmations”) as discussed further below. The Company used the remainder of the net proceeds for general corporate purposes.
Prior to the close of business on the business day immediately preceding September 1, 2021, the 2021 Notes are convertible at the option of the holders of the 2021 Notes only under certain conditions, none of which conditions have been satisfied as of December 31, 2018. On or after September 1, 2021, until the close of business on the second scheduled trading day immediately preceding the maturity date, holders of the 2021 Notes may convert their 2021 Notes at their option at the conversion rate then in effect, irrespective of these conditions. The Company may settle conversions of the 2021 Notes by paying or delivering, as the case may be, cash, shares of Class C capital stock, or a combination of cash and shares of Class C capital stock, at its election. The conversion rate will initially be 19.0985 shares of Class C capital stock per $1,000 principal amount of 2021 Notes (equivalent to an initial conversion price of approximately $52.36 per share of Class C capital stock). The conversion rate is subject to customary adjustments upon the occurrence of certain events. The Company may redeem for cash all or part of the 2021 Notes, at its option, on or after December 6, 2019, under certain circumstances at a redemption price equal to 100% of the principal amount of the 2021 Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date (as defined in the indenture governing the 2021 Notes). The conversion option does not meet the criteria for separate accounting as a derivative as it is indexed to our own stock.
If the Company undergoes a fundamental change (as defined in the indenture governing the 2021 Notes), holders of the 2021 Notes may require the Company to repurchase for cash all or part of their 2021 Notes at a repurchase price equal to 100% of the principal amount of the 2021 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date (as defined in the indenture governing the 2021 Notes). In addition, if certain fundamental changes occur, the Company may be required in certain circumstances to increase the conversion rate for any 2021 Notes converted in connection with such fundamental changes by a specified number of shares of its Class C capital stock. Certain events are also considered “Events of Default,” which may result in the acceleration of the maturity of the 2021 Notes, as described in the indenture governing the notes. There are no financial covenants associated with the 2021 Notes.
We may not redeem the 2021 Notes prior to December 6, 2019. We may redeem the 2021 Notes for cash, at our option, in whole or in part on or after December 6, 2019, if the last reported sale price per share of our Class C capital stock has been at
least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period.
In accounting for the issuance of the 2021 Notes, the Company separated the 2021 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated conversion feature. The carrying amount of the equity component, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the 2021 Notes. The difference between the principal amount of the 2021 Notes and the liability component represents the debt discount, which is recorded as a direct deduction from the related debt liability in the consolidated balance sheet and amortized to interest expense using the effective interest method over the term of the 2021 Notes. The equity component of the 2021 Notes of approximately $91.4 million is included in additional paid-in capital in the consolidated balance sheet and is not remeasured as long as it continues to meet the conditions for equity classification.
The Company incurred transaction costs of approximately $12.2 million related to the issuance of the 2021 Notes, including approximately $11.5 million in fees to the initial purchaser, which amount was paid out of the gross proceeds from the note offering. In accounting for the transaction costs, the Company allocated the total amount incurred to the liability and equity components using the same proportions as the proceeds from the 2021 Notes. Transaction costs attributable to the liability component were recorded as a direct deduction from the related debt liability in the consolidated balance sheet and amortized to interest expense over the term of the 2021 Notes, and transaction costs attributable to the equity component were netted with the equity component in shareholders’ equity.
Interest expense related to the 2021 Notes for the year ended December 31, 2018 was $28.6 million, which is comprised of approximately $19.4 million related to the amortization of debt discount and debt issuance costs and $9.2 million for the contractual coupon interest. Interest expense related to the 2021 Notes for the year ended December 31, 2017 was $27.2 million, which is comprised of approximately $18.0 million related to the amortization of debt discount and debt issuance costs and $9.2 million for the contractual coupon interest. Interest expense related to the 2021 Notes for the year ended December 31, 2016 was $1.3 million, which is comprised of approximately $0.9 million related to the amortization of debt discount and debt issuance costs and $0.5 million for the contractual coupon interest. The effective interest rate on the liability component of the 2021 Notes is 7.44% for the years ended December 31, 2018, 2017 and 2016. Accrued interest related to the 2021 Notes was $0.8 million as of December 31, 2018 and 2017 and is recorded in accrued expenses and other current liabilities in the consolidated balance sheet.
The following table presents the outstanding principal amount and carrying value of the 2021 Notes as of the dates presented (in thousands):
 
Outstanding
Principal
Amount
 
Unamortized
Debt Discount
and Debt
Issuance Costs
 
Carrying
Value
December 31, 2018
$
460,000

 
$
(65,355
)
 
$
394,645

December 31, 2017
$
460,000

 
$
(84,721
)
 
$
375,279


As of December 31, 2018, the unamortized debt discount and debt issuance costs for the 2021 Notes will be amortized to interest expense over a remaining period of approximately 35 months.
The estimated fair value of the 2021 Notes was $446.2 million and $509.0 million, respectively, as of December 31, 2018 and 2017. The estimated fair value of the 2021 Notes was determined through consideration of quoted market prices. The fair value is classified as Level 3 due to the limited trading activity for the 2021 Notes.
The Capped Call Confirmations are expected generally to reduce the potential dilution of our Class C capital stock upon any conversion of 2021 Notes and/or offset the cash payments the Company is required to make in excess of the principal amount of the 2021 Notes in the event that the market price of the Class C capital stock is greater than the strike price of the Capped Call Confirmations (which initially corresponds to the initial conversion price of the 2021 Notes and is subject to certain adjustments under the terms of the Capped Call Confirmations), with such reduction and/or offset subject to a cap based on the cap price of the Capped Call Confirmations. The Capped Call Confirmations have an initial cap price of $69.19 per share, which represents a premium of approximately 85% over the closing price of the Company’s Class C capital stock on The Nasdaq Global Select Market on December 6, 2016, and is subject to certain adjustments under the terms of the Capped Call Confirmations. The Capped Call Confirmations will cover, subject to anti-dilution adjustments substantially similar to those applicable to the 2021 Notes, the number of shares of Class C capital stock that will underlie the 2021 Notes. In addition, the
Capped Call Confirmations provide for the Company to elect, subject to certain conditions, for the Capped Call Confirmations to remain outstanding (with certain modifications) following its election to redeem the 2021 Notes, notwithstanding any conversions of 2021 Notes in connection with such redemption. The Capped Call Confirmations do not meet the criteria for separate accounting as a derivative as they are indexed to our own stock. The premiums paid for the Capped Call Confirmations have been included as a net reduction to additional paid-in capital within shareholders’ equity.
Trulia’s Convertible Senior Notes due in 2020
In connection with the February 2015 acquisition of Trulia, a portion of the total purchase price was allocated to Trulia’s Convertible Senior Notes due in 2020 (the “2020 Notes”), which are unsecured senior obligations. Pursuant to and in accordance with the Merger Agreement, Zillow Group entered into a supplemental indenture in respect of the 2020 Notes in the aggregate principal amount of $230.0 million, which supplemental indenture provides, among other things, that, at the effective time of the Trulia Merger, (i) each outstanding 2020 Note is no longer convertible into shares of Trulia common stock and is convertible solely into shares of Zillow Group Class A common stock, pursuant to, and in accordance with, the terms of the indenture governing the 2020 Notes, and (ii) Zillow Group guaranteed all of the obligations of Trulia under the 2020 Notes and related indenture. In December 2016, the Company used approximately $370.2 million of the net proceeds from the issuance of the 2021 Notes discussed above to repurchase $219.9 million aggregate principal of the 2020 Notes in privately negotiated transactions. The aggregate principal amount of the 2020 Notes is due on December 15, 2020 if not earlier converted or redeemed. Interest is payable on the 2020 Notes at the rate of 2.75% semi-annually on June 15 and December 15 of each year.
Holders of the 2020 Notes may convert all or any portion of their notes, in multiples of $1,000 principal amount, at their option at any time prior to the close of business on the business day immediately preceding the maturity date. Regarding the supplemental indenture in respect of the 2020 Notes, the conversion ratio immediately prior to the effective time of the Trulia Merger of 27.8303 shares of Trulia common stock per $1,000 principal amount of notes was adjusted to 12.3567 shares of our Class A common stock per $1,000 principal amount of notes based on the exchange ratio of 0.444 per the Merger Agreement. This was equivalent to an initial conversion price of approximately $80.93 per share of our Class A common stock. Regarding the August 2015 distribution of shares of our Class C capital stock as a dividend to our Class A and Class B common shareholders, the conversion ratio has been further adjusted to 41.4550 shares of Class A common stock per $1,000 principal amount of notes, which is equivalent to a conversion price of approximately $24.12 per share of our Class A common stock. The conversion ratio will be adjusted for certain dilutive events and will be increased in the case of corporate events that constitute a “Make-Whole Fundamental Change” (as defined in the indenture governing the notes). The conversion option of the 2020 Notes has no cash settlement provisions. The conversion option does not meet the criteria for separate accounting as a derivative as it is indexed to our own stock.
The holders of the 2020 Notes will have the ability to require us to repurchase the notes in whole or in part upon the occurrence of an event that constitutes a “Fundamental Change” (as defined in the indenture governing the notes, including such events as a “change in control” or “termination of trading”, subject to certain exceptions). In such case, the repurchase price would be 100% of the principal amount of the 2020 Notes plus accrued and unpaid interest, if any, to, but excluding, the Fundamental Change repurchase date. Certain events are also considered “Events of Default,” which may result in the acceleration of the maturity of the 2020 Notes, as described in the indenture governing the notes. There are no financial covenants associated with the 2020 Notes.
The 2020 Notes are redeemable, at our option, in whole or in part as of December 20, 2018, if the last reported sale price per share of our Class A common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period.
Interest expense related to the 2020 Notes for the years ended December 31, 2018 and 2017 was $0.3 million, and for the year ended December 31, 2016 was $6.1 million. Accrued interest related to the 2020 Notes as of December 31, 2018 and 2017 was not material. Accrued interest is recorded in accrued expenses and other current liabilities in our consolidated balance sheet.
The carrying value of the 2020 Notes was $9.6 million and $10.1 million, respectively, as of December 31, 2018 and 2017. The estimated fair value of the 2020 Notes was $16.7 million and $17.6 million, respectively, as of December 31, 2018 and 2017. The estimated fair value of the 2020 Notes was determined through consideration of quoted market prices. The fair value is classified as Level 3 due to the limited trading activity for the 2020 Notes.
v3.10.0.1
Income Taxes
12 Months Ended
Dec. 31, 2018
Income Tax Disclosure [Abstract]  
Income Taxes Income Taxes
We are subject to federal and state income taxes in the United States and in Canada. For the years ended December 31, 2018, 2017 and 2016, we did not have a material amount of current taxable income.
We recorded an income tax benefit of $31.1 million for the year ended December 31, 2018. Approximately $15.4 million of the income tax benefit relates to a $69.0 million non-cash impairment we recorded during the year ended December 31, 2018 related to the indefinite-lived Trulia trade names and trademarks intangible asset. The remaining portion of our income tax benefit is primarily the result of net operating losses generated after December 31, 2017 with an indefinite carryforward period due to the Tax Act. Current year net operating losses can now offset against the indefinite-lived deferred tax liabilities which resulted in a release of the valuation allowance and a resulting income tax benefit.
During the year ended December 31, 2018, we completed our accounting for the income tax effects related to the deduction limitations on compensation under the Tax Act. The Internal Revenue Service provided further guidance in applying the written binding contracts requirement under the Tax Act, and we believe certain of our executive compensation previously eligible to be deductible for tax purposes under Section 162(m) of the Internal Revenue Code will be considered grandfathered and, therefore, will continue to be deductible. Based on the clarification of these rules, the accounting related to the Section 162(m) limitation of the Internal Revenue Code is considered complete and as a result we recorded a $5.9 million tax benefit for the year ended December 31, 2018.
We recorded an income tax benefit of $89.6 million for the year ended December 31, 2017. Approximately $66.0 million of the income tax benefit relates to a $174.0 million non-cash impairment we recorded during the year ended December 31, 2017 related to the $351.0 million indefinite-lived intangible asset that we recorded in connection with our February 2015 acquisition of Trulia for Trulia’s trade names and trademarks. For additional information about the non-cash impairment, see Note 11 to our consolidated financial statements. The remaining $23.6 million of the income tax benefit primarily relates to our initial analysis of the impact of the rate decrease included in the Tax Act for the impact of the reduction in our net deferred tax liability related to our indefinite-lived intangible asset.
The following table summarizes the components of our income tax (benefit) expense for the periods presented (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Current income tax expense
 
 
 
 
 
     Foreign
$
161

 
$

 
$

Total current income tax expense
161

 

 

Deferred income tax (benefit) expense
 
 
 
 
 
     Federal
(28,502
)
 
(84,238
)
 
(1,248
)
     State
(2,441
)
 
(5,348
)
 
1,378

     Foreign
(320
)
 

 

Total deferred income tax (benefit) expense
(31,263
)
 
(89,586
)
 
130

Total income tax (benefit) expense
$
(31,102
)
 
$
(89,586
)
 
$
130


The following table presents a reconciliation of the federal statutory rate and our effective tax rate for the periods presented:
 
Year Ended December 31,
 
2018
 
2017
 
2016
Tax expense at federal statutory rate
(21.0
)%
 
(35.0
)%
 
(35.0
)%
State income taxes, net of federal tax benefit
(5.9
)
 
(4.4
)
 
(1.9
)
Nondeductible expenses

 
0.8

 
4.9

Share-based compensation
(16.5
)
 
(20.6
)
 
(0.2
)
IRC section 162(m)
1.0

 

 

Research and development credits
(8.4
)
 
(6.3
)
 
(1.5
)
Meals and entertainment
1.8

 

 

Return to provision adjustments
(4.2
)
 

 

Enactment of Tax Act
(1.9
)
 
(13.1
)
 

Other
0.4

 
2.2

 
(0.9
)
Valuation allowance
34.0

 
27.7

 
34.7

Effective tax rate
(20.7
)%
 
(48.7
)%
 
0.1
 %

Deferred federal, state and foreign income taxes reflect the net tax impact of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and such amounts for tax purposes. The following table presents the significant components of our deferred tax assets and liabilities as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Deferred tax assets:
 
 
 
Federal and state net operating loss carryforwards
$
259,629

 
$
234,316

Share-based compensation
55,280

 
47,655

Start-up and organizational costs
99

 
146

Research and development credits
48,805

 
35,793

Other tax credits
910

 
910

Accruals and reserves
3,000

 
2,729

Deferred rent
4,842

 
5,484

Other deferred tax assets
14,267

 
8,342

Total deferred tax assets
386,832

 
335,375

Deferred tax liabilities:
 
 
 
Website and software development costs
(14,685
)
 
(13,202
)
Goodwill
(598
)
 
(688
)
Intangible assets
(45,035
)
 
(69,241
)
Discount on 2021 Notes and 2023 Notes not deductible for tax
(31,450
)
 
(19,374
)
Depreciation and amortization
(888
)
 
(2,425
)
Total deferred tax liabilities
(92,656
)
 
(104,930
)
Net deferred tax assets before valuation allowance
294,176

 
230,445

Less: valuation allowance
(307,599
)
 
(274,810
)
Net deferred tax liabilities
$
(13,423
)
 
$
(44,365
)

Realization of deferred tax assets is dependent upon the generation of future taxable income, if any, the timing and amount of which are uncertain. We have provided a full valuation allowance against the net deferred tax assets as of December 31, 2018 and 2017 because, based on the weight of available evidence, it is more likely than not (a likelihood of more than 50%) that some or all of the deferred tax assets will not be realized. The valuation allowance increased by $32.8 million and $57.5 million, respectively, during the years ended December 31, 2018 and 2017.
We have accumulated federal tax losses of approximately $1,081.7 million and $1,014.0 million, respectively, as of December 31, 2018 and 2017, which are available to reduce future taxable income. We have accumulated state tax losses of approximately $32.5 million and $21.4 million (tax effected), respectively, as of December 31, 2018 and 2017. Additionally, we have net research and development credit carryforwards of $48.8 million and $35.8 million, respectively, as of December 31, 2018 and 2017, which are available to reduce future tax liabilities. The tax loss and research and development credit
carryforwards begin to expire in 2025. Under Sections 382 and 383 of the Internal Revenue Code, if a corporation undergoes an ownership change, the corporation’s ability to use its pre-change net operating loss carryforwards and other pre-change tax attributes, such as research tax credits, to offset its post-change income or income tax liability may be limited. In connection with our August 2013 public offering of our Class A Common stock, we experienced an ownership change that triggered Sections 382 and 383, which may limit our ability to utilize net operating loss and tax credit carryforwards. In connection with our February 2015 acquisition of Trulia, Trulia experienced an ownership change that triggered Section 382 and 383, which may limit Zillow Group’s ability to utilize Trulia’s net operating loss and tax credit carryforwards.
We are currently not under audit in any tax jurisdiction. Tax years from 2015 through 2018 are currently open for audit by federal and state taxing authorities.
Changes for unrecognized tax benefits for the periods presented are as follows (in thousands):
Balance at January 1, 2016
$
13,980

Gross increases—prior and current period tax positions
2,619

Gross decreases—prior period tax positions
(1,204
)
Balance at December 31, 2016
$
15,395

Gross increases—current period tax positions
5,216

Gross increases—prior period tax positions
1,002

Balance at December 31, 2017
$
21,613

Gross increases—current period tax positions
6,421

Gross increases—prior period tax positions
591

Balance at December 31, 2018
$
28,625


At December 31, 2018, the total amount of unrecognized tax benefits of $28.6 million is recorded as a reduction to our deferred tax asset. We do not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease within the next 12 months. Accrued interest and penalties related to unrecognized tax benefits are recorded as income tax expense and are zero.
v3.10.0.1
Shareholders' Equity
12 Months Ended
Dec. 31, 2018
Equity [Abstract]  
Shareholders' Equity Shareholders’ Equity
Preferred Stock
Our board of directors has the authority to fix and determine and to amend the number of shares of any series of preferred stock that is wholly unissued or to be established and to fix and determine and to amend the designation, preferences, voting powers and limitations, and the relative, participating, optional or other rights, of any series of shares of preferred stock that is wholly unissued or to be established, subject in each case to certain approval rights of holders of our outstanding Class B common stock. There was no preferred stock issued and outstanding as of December 31, 2018 or December 31, 2017.
Common and Capital Stock
Our Class A common stock has no preferences or privileges and is not redeemable. Holders of Class A common stock are entitled to one vote for each share.
Our Class B common stock has no preferences or privileges and is not redeemable. At any time after the date of issuance, each share of Class B common stock, at the option of the holder, may be converted into one share of Class A common stock, or automatically converted into Class A common stock upon the affirmative vote by or written consent of holders of a majority of the shares of the Class B common stock. During the years ended December 31, 2018, 2017 and 2016, no shares of Class B common stock were converted into Class A common stock at the option of the holders. Holders of Class B common stock are entitled to 10 votes for each share.
Our Class C capital stock has no preferences or privileges, is not redeemable and, except in limited circumstances, is non-voting. On July 3, 2018, Zillow Group issued and sold 6,557,017 shares (of which 855,263 shares were related to the exercise of the underwriters’ option to purchase additional shares) of our Class C capital stock at a public offering price of $57.00 per share. We received net proceeds of $360.3 million after deducting underwriting discounts and commissions and offering expenses payable by us.
The following shares of common and capital stock have been reserved for future issuance as of the dates presented:
 
December 31, 2018
 
December 31, 2017
Option awards outstanding
27,310,110

 
26,645,206

Restricted stock units outstanding
5,266,324

 
4,016,405

Class A common stock and Class C capital stock available for grant under 2011 Plan
3,675,082

 
5,076,898

Shares issuable upon conversion of outstanding Class B common stock
6,217,447

 
6,217,447

Total
42,468,963

 
41,955,956

v3.10.0.1
Share-Based Awards
12 Months Ended
Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Share-Based Awards Share-Based Awards
In connection with our February 2015 acquisition of Trulia, we assumed the obligations of Zillow and Trulia outstanding under pre-existing stock plans. We intend that future equity grants will be made under Zillow Group’s 2011 Amended and Restated Incentive Plan (as amended and/or restated from time to time, the “2011 Plan”) only (or a successor thereto).
Zillow Group, Inc. Amended and Restated 2011 Incentive Plan
On July 19, 2011, the 2011 Plan became effective. In addition to the share reserve of 18,400,000 shares, the number of shares available for issuance under the 2011 Plan automatically increases on the first day of each of our fiscal years by a number of shares equal to the least of (a) 3.5% of our outstanding Class A common stock, Class B common stock, and Class C capital stock on a fully diluted basis as of the end of our immediately preceding fiscal year, (b) 10,500,000 shares, and (c) a lesser amount determined by our board of directors; provided, however, that any shares from any increases in previous years that are not actually issued will continue to be available for issuance under the 2011 Plan. In addition, shares previously available for grant under Zillow, Inc.’s 2005 Equity Incentive Plan (the “2005 Plan”), but not issued or subject to outstanding awards under the 2005 Plan as of July 19, 2011, and shares subject to outstanding awards under the 2005 Plan that subsequently cease to be subject to such awards (other than by reason of exercise of the awards) are available for grant under the 2011 Plan. The 2011 Plan is administered by the compensation committee of the board of directors. Under the terms of the 2011 Plan, the compensation committee may grant equity awards, including incentive stock options, nonqualified stock options, restricted stock, restricted stock units or restricted units to employees, officers, directors, consultants, agents, advisers and independent contractors. The board of directors has also authorized certain senior executive officers to grant equity awards under the 2011 Plan, within limits prescribed by our board of directors. The 2011 Plan provides that in the event of a stock dividend, stock split or similar event, the maximum number and kind of securities available for issuance under the plan will be proportionally adjusted.
Options under the 2011 Plan are granted with an exercise price per share not less than 100% of the fair market value of our stock on the date of grant, with the exception of substituted option awards granted in connection with acquisitions, and are exercisable at such times and under such conditions as determined by the compensation committee. Any portion of an option that is not vested and exercisable on the date of a participant’s termination of service expires on such date. Employees generally forfeit their rights to exercise vested options 3 months following their termination of employment or 12 months following termination by reason of death, disability or retirement. Options granted under the 2011 Plan typically expire seven or ten years from the grant date and typically vest either 25% after 12 months and ratably thereafter over the next 36 months or quarterly over a period of four years, though certain options have been granted with alternative vesting schedules.
Restricted stock units granted under the 2011 Plan typically vest either 25% after 12 months and quarterly thereafter over the next three years, quarterly over a period of four years, or 12.5% after 6 months and quarterly thereafter for the next 3.5 years. Any portion of a restricted stock unit that is not vested on the date of a participant’s termination of service expires on such date.
In March 2016, Zillow Group established an equity choice program pursuant to which Zillow Group grants restricted stock units and option awards to acquire shares of Class C capital stock to certain employees to retain and recognize their efforts on behalf of Zillow Group.
Trulia 2005 Stock Incentive Plan
Trulia granted options under its 2005 Stock Incentive Plan (as amended, “the 2005 Plan”) until September 2012 when the 2005 Plan was terminated. Stock options issued prior to the plan termination remained outstanding in accordance with their terms. Under the terms of the 2005 Plan, Trulia had the ability to grant incentive and nonqualified stock options, stock appreciation rights, restricted stock awards and restricted stock units. Options granted under the 2005 Plan generally vest at a rate of 25% after 12 months and ratably thereafter over the next 36 months and expire 10 years from the grant date. Certain options vest monthly over two to four years.
Trulia 2012 Equity Incentive Plan, as Amended and Restated
On September 19, 2012, Trulia’s 2012 Equity Incentive Plan (the “2012 Plan”) became effective. The 2012 Plan provides for the grant of incentive and nonqualified stock options, restricted stock, restricted stock units, stock appreciation rights, performance units and performance shares to employees, directors and consultants. Under the 2012 Plan, stock options are granted at a price per share not less than 100% of the fair market value per share of the underlying stock at the grant date. The plan administrator determines the vesting period for each option award on the grant date, and the options generally expire 10 years from the grant date or such shorter term as may be determined for the options. As noted above, we intend that future equity grants will be made under the 2011 Plan only.
Option Awards
The following table summarizes option award activity for the year ended December 31, 2018:
 
Number
of Shares
Subject to
Existing
Options
 
Weighted-
Average
Exercise
Price Per
Share
 
Weighted-
Average
Remaining
Contractual
Life (Years)
 
Aggregate
Intrinsic
Value
(in
thousands)
Outstanding at January 1, 2018
26,645,206

 
$
27.70

 
5.72
 
$
355,739

Granted
6,963,320

 
48.95

 

 

Exercised
(5,472,728
)
 
21.94

 

 

Forfeited or cancelled
(825,688
)
 
35.32

 

 

Outstanding at December 31, 2018
27,310,110

 
34.04

 
6.23
 
97,941

Vested and exercisable at December 31, 2018
15,287,932

 
29.73

 
4.72
 
75,867


The fair value of options granted is estimated at the date of grant using the Black-Scholes-Merton option-pricing model, assuming no dividends and with the following assumptions for the periods presented: 
 
Year Ended December 31,
 
2018
 
2017
 
2016
Expected volatility
42% – 45%
 
45% – 49%
 
49% – 51%
Expected dividend yield
 
 
Risk-free interest rate
2.52% – 2.84%
 
1.67% – 2.06%
 
0.89% – 1.89%
Weighted-average expected life
4.50 – 5.00 years
 
4.25 – 4.75 years
 
3.75 – 4.25 years
Weighted-average fair value of options granted
$19.11
 
$14.51
 
$9.42

As of December 31, 2018, there was a total of $176.7 million in unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted-average period of 2.7 years.
The total intrinsic value of options exercised during the years ended December 31, 2018, 2017 and 2016 was $161.4 million, $156.1 million and $51.7 million, respectively. The fair value of options vested for the years ended December 31, 2018, 2017 and 2016 was $87.7 million, $84.8 million and $87.9 million, respectively.
Restricted Stock Units
The following table summarizes activity for restricted stock units for the year ended December 31, 2018:
 
Restricted
Stock Units
 
Weighted-
Average Grant-
Date Fair
Value
Unvested outstanding at January 1, 2018
4,016,405

 
$
33.22

Granted
3,725,726

 
48.26

Vested
(1,740,134
)
 
35.63

Forfeited or cancelled
(735,673
)
 
39.59

Unvested outstanding at December 31, 2018
5,266,324

 
42.19


The total fair value of vested restricted stock units was $62.0 million, $43.7 million and $46.5 million, respectively, for the years ended December 31, 2018, 2017 and 2016.
The fair value of the outstanding restricted stock units will be recorded as share-based compensation expense over the vesting period. As of December 31, 2018, there was $204.9 million of total unrecognized compensation cost related to restricted stock units, which is expected to be recognized over a weighted-average period of 2.9 years.
Share-Based Compensation Expense
The following table presents the effects of share-based compensation expense in our consolidated statements of operations during the periods presented (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Cost of revenue
$
4,127

 
$
3,884

 
$
3,550

Sales and marketing
22,942

 
22,735

 
23,320

Technology and development
56,673

 
39,938

 
31,466

General and administrative
65,342

 
47,014

 
48,582

 
$
149,084

 
$
113,571

 
$
106,918

v3.10.0.1
Net Loss Per Share
12 Months Ended
Dec. 31, 2018
Earnings Per Share [Abstract]  
Net Loss Per Share Net Loss Per Share
Basic net loss per share is computed by dividing net loss by the weighted-average number of shares (including Class A common stock, Class B common stock and Class C capital stock) outstanding during the period. In the calculation of basic net loss per share, undistributed earnings are allocated assuming all earnings during the period were distributed.
Diluted net loss per share is computed by dividing net loss by the weighted-average number of shares (including Class A common stock, Class B common stock and Class C capital stock) outstanding during the period and potentially dilutive Class A common stock and Class C capital stock equivalents, except in cases where the effect of the Class A common stock or Class C capital stock equivalent would be antidilutive. Potential Class A common stock and Class C capital stock equivalents consist of Class A common stock and Class C capital stock issuable upon exercise of stock options and Class A common stock and Class C capital stock underlying unvested restricted stock awards and unvested restricted stock units using the treasury stock method. Potential Class A common stock equivalents also include Class A common stock issuable upon conversion of the 2020 Notes using the if-converted method.
Since the Company expects to settle the principal amount of the outstanding 2021 Notes and 2023 Notes in cash, the Company uses the treasury stock method for calculating any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. For the 2021 Notes, the conversion spread of approximately 8.8 million shares has a dilutive impact on diluted net income per share when the market price of the Company’s Class C capital stock at the end of a period exceeds the conversion price of $52.36 per share. For the 2023 Notes, the conversion spread of approximately 4.8 million shares has a dilutive impact on diluted net income per share when the market price of the Company’s Class C capital stock at the end of a period exceeds the conversion price of $78.37 per share.
For the periods presented, the following Class A common stock and Class C capital stock equivalents were excluded from the calculations of diluted net loss per share because their effect would have been antidilutive (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Weighted-average Class A common stock and Class C capital stock option awards outstanding
22,736

 
27,998

 
19,993

Weighted-average Class A common stock and Class C capital stock restricted stock units outstanding
4,949

 
4,262

 
3,607

Class A common stock issuable upon conversion of the 2020 Notes
400

 
435

 
440

Total Class A common stock and Class C capital stock equivalents
28,085

 
32,695

 
24,040


In the event of liquidation, dissolution, distribution of assets or winding-up of the Company, the holders of all classes of common and capital stock have equal rights to receive all the assets of the Company after the rights of the holders of preferred stock have been satisfied. We have not presented net loss per share under the two-class method for our Class A common stock, Class B common stock and Class C capital stock because it would be the same for each class due to equal dividend and liquidation rights for each class.
v3.10.0.1
Commitments and Contingencies
12 Months Ended
Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies Commitments and Contingencies
Lease Commitments
We have contractual obligations in the form of operating leases for office space and office equipment. The largest of these leases relates to our headquarters in Seattle, Washington, as well as our other offices in San Francisco, California, Denver, Colorado, Overland Park, Kansas, Irvine, California and New York, New York. Each of these leases contain periodic rent escalation adjustments and renewal options. Rent expense related to these leases is recorded on a straight-line basis. Our operating lease obligations expire at various dates with the latest maturity in 2024.
Future minimum payments for all operating leases as of December 31, 2018 are as follows (in thousands): 
2019
$
29,085

2020
38,060

2021
40,099

2022
37,721

2023
36,458

All future years
85,462

Total future minimum lease payments
$
266,885


Rent expense for the years ended December 31, 2018, 2017 and 2016, was $23.7 million, $21.4 million and $16.6 million, respectively.
Purchase Commitments
Purchase commitments primarily included non-cancelable agreements to purchase content related to our mobile applications and websites as well as homes that the Company is under contract to purchase through Zillow Offers but that have not closed as of the respective date. The amounts due for these non-cancelable purchase commitments and homes under contract as of December 31, 2018 are as follows (in thousands):
 
Purchase Obligations
 
Homes Under Contract
2019
$
64,124

 
$
88,943

2020
64,007

 

2021
32,735

 

Total future purchase commitments
$
160,866

 
$
88,943


Surety Bonds
In the course of business, we are required to provide financial commitments in the form of surety bonds to third parties as a guarantee of our performance on and our compliance with certain obligations. If we were to fail to perform or comply with these obligations, any draws upon surety bonds issued on our behalf would then trigger our payment obligation to the surety
bond issuer. We have outstanding surety bonds issued for our benefit of approximately $8.9 million and $3.7 million as of December 31, 2018 and 2017, respectively.
Legal Proceedings
We are involved in a number of legal proceedings concerning matters arising in connection with the conduct of our business activities, some of which are at preliminary stages and some of which seek an indeterminate amount of damages. We regularly evaluate the status of legal proceedings in which we are involved to assess whether a loss is probable or there is a reasonable possibility that a loss or additional loss may have been incurred to determine if accruals are appropriate. We further evaluate each legal proceeding to assess whether an estimate of possible loss or range of loss can be made if accruals are not appropriate. For certain cases described below, management is unable to provide a meaningful estimate of the possible loss or range of possible loss because, among other reasons, (i) the proceedings are in preliminary stages; (ii) specific damages have not been sought; (iii) damages sought are, in our view, unsupported and/or exaggerated; (iv) there is uncertainty as to the outcome of pending appeals or motions; (v) there are significant factual issues to be resolved; and/or (vi) there are novel legal issues or unsettled legal theories presented. For these cases, however, management does not believe, based on currently available information, that the outcomes of these proceedings will have a material effect on our financial position, results of operations or cash flow.
In July 2015, VHT, Inc. (“VHT”) filed a complaint against us in the U.S. District Court for the Western District of Washington alleging copyright infringement of VHT’s images on the Zillow Digs site. In January 2016, VHT filed an amended complaint alleging copyright infringement of VHT’s images on the Zillow Digs site as well as the Zillow listing site. In December 2016, the court granted a motion for partial summary judgment that dismissed VHT’s claims with respect to the Zillow listing site. A federal jury trial began on January 23, 2017, and on February 9, 2017, the jury returned a verdict finding that the Company had infringed VHT’s copyrights in images displayed or saved to the Digs site. The jury awarded VHT $79,875 in actual damages and approximately $8.2 million in statutory damages. In March 2017, the Company filed motions in the district court seeking judgment for the Company on certain claims that are the subject of the verdict, and for a new trial on others. On June 20, 2017, the judge ruled and granted in part our motions, finding that VHT failed to present sufficient evidence to prove direct copyright infringement for a portion of the images, reducing the total damages to approximately $4.1 million. On October 26, 2017, the Company filed an appeal with the Ninth Circuit Court of Appeals seeking review of the final judgment and certain prior rulings entered by the district court. The oral hearing for the appeal took place on August 28, 2018. We have recorded an estimated liability for approximately $4.1 million as of December 31, 2018 and December 31, 2017. We do not believe there is a reasonable possibility that a material loss in excess of amounts accrued may be incurred.
In August and September 2017, two purported class action lawsuits were filed against us and certain of our executive officers, alleging, among other things, violations of federal securities laws on behalf of a class of those who purchased our common stock between February 12, 2016 and August 8, 2017. One of those purported class actions, captioned Vargosko v. Zillow Group, Inc. et al, was brought in the U.S. District Court for the Central District of California. The other purported class action lawsuit, captioned Shotwell v. Zillow Group, Inc. et al, was brought in the U.S. District Court for the Western District of Washington. The complaints allege, among other things, that during the period between February 12, 2016 and August 8, 2017, we issued materially false and misleading statements regarding our business practices. The complaints seek to recover, among other things, alleged damages sustained by the purported class members as a result of the alleged misconduct. In November 2017, an amended complaint was filed against us and certain of our executive officers in the Shotwell v. Zillow Group class action lawsuit, extending the beginning of the class period to November 17, 2014. In January 2018, the Vargosko v. Zillow Group class action lawsuit was transferred to the U.S. District Court for the Western District of Washington and consolidated with the Shotwell v. Zillow Group class action lawsuit, and the court appointed lead plaintiffs in the consolidated lawsuit. In February 2018, lead plaintiffs filed a consolidated amended complaint, and in April 2018, we filed our motion to dismiss the consolidated amended complaint. Our motion to dismiss the consolidated amended complaint was fully briefed in June 2018. On October 2, 2018, the court granted our motion to dismiss, although the court gave lead plaintiffs 45 days, or until November 16, 2018, to file a second consolidated amended complaint and attempt to cure the defects in their consolidated amended complaint. On November 16, 2018, lead plaintiffs filed a second consolidated amended complaint, which we moved to dismiss on December 17, 2018. We anticipate that briefing on our motion to dismiss the second consolidated amended complaint will be complete by February 6, 2019. We have denied the allegations of wrongdoing and intend to vigorously defend the claims in this lawsuit. We have not recorded an accrual related to this lawsuit as of December 31, 2018 and December 31, 2017, as we do not believe a loss is probable.
In October and November 2017 and January and February 2018, four shareholder derivative lawsuits were filed in the U.S. District Court for the Western District of Washington and the Superior Court of the State of Washington, against certain of our executive officers and directors seeking unspecified damages on behalf of the Company and certain other relief, such as reform to corporate governance practices. The plaintiffs in the derivative lawsuits (in which the Company is a nominal
defendant) allege, among other things, that the defendants breached their fiduciary duties in connection with oversight of public statements and legal compliance, and as a result of the breach of such fiduciary duties, the Company was damaged, and defendants were unjustly enriched. Certain of the plaintiffs also allege, among other things, violations of Section 14(a) of the Securities Exchange Act of 1934 and waste of corporate assets. All four of the shareholder derivative lawsuits have been stayed until after final resolution of the pending motion to dismiss and related appeals, if any, in the consolidated securities class action lawsuit discussed above. The defendants intend to deny the allegations of wrongdoing and vigorously defend the claims in these lawsuits. We have not recorded an accrual related to these lawsuits as of December 31, 2018 and December 31, 2017, as we do not believe a loss is probable.
In addition to the matters discussed above, from time to time, we are involved in litigation and claims that arise in the ordinary course of business. Although we cannot be certain of the outcome of any such litigation or claims, nor the amount of damages and exposure that we could incur, we currently believe that the final disposition of such matters will not have a material effect on our business, financial position, results of operations or cash flow. Regardless of the outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources and other factors.
Indemnifications
In the ordinary course of business, we enter into contractual arrangements under which we agree to provide indemnification of varying scope and terms to business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of the breach of such agreements and out of intellectual property infringement claims made by third parties. In addition, we have agreements that indemnify certain issuers of surety bonds against losses that they may incur as a result of executing surety bonds on our behalf. For our indemnification arrangements, payment may be conditional on the other party making a claim pursuant to the procedures specified in the particular contract. Further, our obligations under these agreements may be limited in terms of time and/or amount, and in some instances, we may have recourse against third parties for certain payments. In addition, we have indemnification agreements with certain of our directors and executive officers that require us, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The terms of such obligations may vary.
v3.10.0.1
Related Party Transactions
12 Months Ended
Dec. 31, 2018
Related Party Transactions [Abstract]  
Related Party Transactions Related Party Transactions
In February 2016, we paid a total of approximately $0.2 million and $0.2 million, respectively, to Mr. Lloyd Frink, our Vice Chairman and President, and Mr. Richard Barton, our Executive Chairman, for reimbursement of costs incurred by Mr. Frink and Mr. Barton for use of private planes by certain of the Company’s employees and Mr. Frink and Mr. Barton for business travel in prior years.
In April 2016, we paid approximately $0.1 million for a tax “gross-up” payment to Mr. Richard Barton, our Executive Chairman, to cover the imputed income associated with a 2015 Federal Trade Commission filing made on behalf of Mr. Barton under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, which filing was required due to Mr. Barton’s ownership of Zillow, Inc.’s common stock.
v3.10.0.1
Self-Insurance
12 Months Ended
Dec. 31, 2018
Insurance [Abstract]  
Self-Insurance Self-InsuranceWe are self-insured for medical benefits, and beginning on January 1, 2018 for dental benefits, for all qualifying Zillow Group employees. The medical plan carries a stop-loss policy which will protect when cumulative medical claims exceed 125% of expected claims for the plan year with a limit of $1.0 million and from individual claims during the plan year exceeding $150,000. We record estimates of the total costs of claims incurred based on an analysis of historical data and independent estimates. Our liability for self-insured claims is included within accrued compensation and benefits in our consolidated balance sheet and was $3.9 million and $2.0 million, respectively, as of December 31, 2018 and 2017.
v3.10.0.1
Employee Benefit Plan
12 Months Ended
Dec. 31, 2018
Retirement Benefits [Abstract]  
Employee Benefit Plan Employee Benefit PlanWe have a defined contribution 401(k) retirement plan covering Zillow Group employees who have met certain eligibility requirements (the “Zillow Group 401(k) Plan”). Eligible employees may contribute pretax compensation up to a maximum amount allowable under the Internal Revenue Service limitations. Employee contributions and earnings thereon vest immediately. We currently match up to 4% of employee contributions under the Zillow Group 401(k) Plan. The total expense related to the Zillow Group 401(k) Plan was $16.0 million, $12.3 million and $10.1 million, respectively, for the years ended December 31, 2018, 2017 and 2016.
v3.10.0.1
Segment Information and Revenue
12 Months Ended
Dec. 31, 2018
Segment Reporting [Abstract]  
Segment Information and Revenue Segment Information and Revenue
Beginning in the second quarter of 2018, we have two operating and reportable segments, which have been identified based on the way in which our chief operating decision-maker manages our business, makes operating decisions and evaluates operating performance. Our chief executive officer acts as the chief operating decision-maker and reviews financial and operational information of the IMT and Homes segments.
The IMT segment includes the financial results for the Premier Agent, Rentals, Mortgages and new construction marketplaces, dotloop, and display, as well as revenue from the sale of various other marketing and business products and services to real estate professionals. The Homes segment includes the financial results from Zillow Group’s buying and selling of homes directly.
Revenue and costs are generally directly attributed to our segments. However, due to the integrated structure of our business, certain costs incurred by one segment may benefit the other segment. These costs are generally headcount-related and are allocated to each segment based on the estimated effort attributable to each segment.
Our chief executive officer reviews information about our revenue categories as well as statement of operations data inclusive of loss before income taxes by segment. This information is included in the following table for the period presented (in thousands): 
 
Year Ended December 31, 2018
 
IMT
 
Homes
 
Consolidated
Revenue:
 
 
 
 
 
Premier Agent
$
898,332

 
$

 
$
898,332

Rentals
134,587

 

 
134,587

Mortgages
80,046

 

 
80,046

Other
168,224

 

 
168,224

Homes

 
52,365

 
52,365

Total revenue
1,281,189

 
52,365

 
1,333,554

Costs and expenses:
 
 
 
 
 
Cost of revenue
104,330

 
49,260

 
153,590

Sales and marketing
534,038

 
18,583

 
552,621

Technology and development
389,539

 
21,279

 
410,818

General and administrative
238,727

 
23,426

 
262,153

Impairment costs
79,000

 

 
79,000

Acquisition-related costs
2,332

 

 
2,332

Integration costs
2,015

 

 
2,015

Total costs and expenses
1,349,981

 
112,548

 
1,462,529

Income (loss) from operations
(68,792
)
 
(60,183
)
 
(128,975
)
Other income
19,270

 

 
19,270

Interest expense
(39,078
)
 
(2,177
)
 
(41,255
)
Loss before income taxes
$
(88,600
)
 
$
(62,360
)
 
$
(150,960
)

We have not presented the comparable 2017 or 2016 periods in the table above because we had one operating and reportable segment prior to 2018.
v3.10.0.1
Subsequent Events
12 Months Ended
Dec. 31, 2018
Subsequent Events [Abstract]  
Subsequent Events Subsequent Events
Entry into Revolving Credit Agreement
On January 31, 2019, certain of Zillow Group’s wholly owned subsidiaries entered into a revolving credit agreement with Citibank, N.A., as the directing lender, and certain other parties thereto (the “Credit Agreement”). The Credit Agreement provides for a maximum borrowing capacity of $500.0 million (the “Maximum Amount”) with an initial borrowing capacity
of $50.0 million, which amount may be increased up to the Maximum Amount subject to the satisfaction of certain conditions, through a non-recourse credit facility secured by a pledge of the equity of certain subsidiaries that purchase and sell select residential properties through Zillow Offers. The Credit Agreement has an initial term of two years which may be extended for up to one year, subject to the satisfaction of certain conditions. The Credit Agreement includes customary representations and warranties, covenants (including financial covenants applicable to the Company), and provisions regarding events of default.
Appointment of CEO; Compensatory Arrangements
On February 21, 2019, Zillow Group announced the appointment of Richard N. Barton as Zillow Group’s Chief Executive Officer, effective February 21, 2019. Mr. Barton will succeed Spencer Rascoff, who has served as Zillow Group’s Chief Executive Officer since 2010 and who will remain a member of Zillow Group’s board of directors. Mr. Barton also will remain a member of Zillow Group’s board of directors. In connection with Mr. Rascoff’s resignation as Chief Executive Officer, which occurred on February 21, 2019, Zillow Group entered into an Executive Departure Agreement and Release (the “Agreement”) with Mr. Rascoff. Pursuant to the Agreement, Mr. Rascoff will remain a full-time employee of Zillow Group at his current level of compensation and benefits until March 22, 2019 (the “Departure Date”) in order to provide transition services until such date. Mr. Rascoff will remain a member of Zillow Group’s board of directors.
Pursuant to the Agreement, Mr. Rascoff will be eligible to receive, among other things, accelerated vesting of outstanding stock options held by Mr. Rascoff as of the Departure Date by an additional eighteen months from the Departure Date. Options not vested as of the Departure Date, taking into account the foregoing vesting acceleration, will terminate. Each of Mr. Rascoff’s vested stock options that are outstanding as of the Departure Date will remain exercisable until, except for any later date contemplated by the following proviso, the later of (x) the third anniversary of the Departure Date and (y) the latest day upon which the option would have expired by its original terms under any circumstances (the “Option Expiration Outside Date”); provided, however, that the options will remain exercisable for so long as Mr. Rascoff serves on Zillow Group’s board of directors (but not later than any applicable Option Expiration Outside Date), and if Mr. Rascoff ceases to serve on Zillow Group’s board of directors on or after the third anniversary of the Departure Date, each option will remain exercisable until the earlier of (i) ninety days from the final date of Mr. Rascoff’s service on Zillow Group’s board of directors and (ii) the applicable Option Expiration Outside Date. The vesting acceleration pursuant to the Agreement will be accounted for as a modification, and we expect to record a material amount of share-based compensation expense associated with this modification in the three months ended March 31, 2019.
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Summary of Significant Accounting Policies (Policies)
12 Months Ended
Dec. 31, 2018
Accounting Policies [Abstract]  
Basis of Presentation Basis of PresentationThe accompanying consolidated financial statements include Zillow Group, Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. These consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”).
Use of Estimates Use of EstimatesThe preparation of financial statements in conformity with GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. On an ongoing basis, we evaluate our estimates, including those related to the net realizable value of inventory, amortization period and recoverability of contract cost assets, website and software development costs, recoverability of long-lived assets and intangible assets with definite lives, share-based compensation, income taxes, business combinations, and the recoverability of goodwill and indefinite-lived intangible assets, among others. To the extent there are material differences between these estimates, judgments, or assumptions and actual results, our financial statements will be affected.
Concentrations of Credit Risk Concentrations of Credit Risk
Financial instruments, which potentially subject us to concentrations of credit risk, consist primarily of cash and cash equivalents, investments, accounts receivable and mortgage loans held for sale. We place cash and cash equivalents and investments with major financial institutions, which management assesses to be of high credit quality, in order to limit exposure of our investments.
Credit risk with respect to accounts receivable is dispersed due to the large number of customers. There were no customers that comprised 10% or more of our total accounts receivable as of December 31, 2018 and 2017. Further, our credit risk on accounts receivable is mitigated by the relatively short payment terms that we offer. Collateral is not required for accounts receivable. We maintain an allowance for doubtful accounts such that receivables are stated at net realizable value.
Similarly, our credit risk on mortgage loans held for sale is dispersed due to a large number of customers. Further, our credit risk on mortgage loans held for sale is mitigated by the fact that we typically sell mortgages on the secondary market within a relatively short period of time after the loan is originated.
Cash and Cash Equivalents/Restricted Cash Restricted CashRestricted cash consists of amounts funded to the reserve and collection accounts related to our Revolving Credit Facility (see Note 14) and amounts held in escrow related to funding home purchases in our mortgage originations business.Cash and Cash EquivalentsCash includes demand deposits with banks or financial institutions. Cash equivalents include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Our cash equivalents include only investments with original maturities of three months or less. We regularly maintain cash in excess of federally insured limits at financial institutions.
Short-term Investments Short-term InvestmentsOur investments consist of fixed income securities, which include U.S. and foreign government agency securities, corporate notes and bonds, commercial paper, municipal securities and certificates of deposit, and are classified as available-for-sale securities. As the investments are available to support current operations, our available-for-sale securities are classified as short-term investments. Available-for-sale securities are carried at fair value with unrealized gains and losses reported as a component of accumulated other comprehensive loss in shareholders’ equity, while realized gains and losses and other-than-temporary impairments are reported as a component of net loss based on specific identification. An impairment charge is recorded in the consolidated statements of operations for declines in fair value below the cost of an individual investment that are deemed to be other than temporary. We assess whether a decline in value is temporary based on the length of time that the fair market value has been below cost, the severity of the decline and the intent and ability to hold or sell the investment.
Accounts Receivable and Allowance for Doubtful Accounts Accounts Receivable and Allowance for Doubtful Accounts
Accounts receivable represent our unconditional right to consideration. Accounts receivable are generally due within 30 days and are recorded net of the allowance for doubtful accounts. We consider accounts outstanding longer than the contractual terms past due. We review accounts receivable on a regular basis and estimate an amount of losses for uncollectible accounts based on our historical collections experience, age of the receivable, knowledge of the customer and the condition of the general economy and industry as a whole. We record changes in our estimate to the allowance for doubtful accounts through bad debt expense and relieve the allowance when accounts are ultimately determined to be uncollectible. Bad debt expense is included in general and administrative expenses.
Mortgage Loans Held for Sale Mortgage Loans Held for Sale
Mortgage loans held for sale includes residential mortgages originated for sale in the secondary market in connection with our October 2018 acquisition of MLOA. We have elected the fair value option for all mortgage loans held for sale as election of this option allows for a better offset of the changes in fair values of the loans and the derivative instruments used to economically hedge them without having to apply complex hedge accounting provisions. Mortgage loans held for sale are initially recorded at fair value based on either sale commitments or current market quotes and are adjusted for subsequent changes in fair value until the loans are sold. Net origination costs and fees associated with mortgage loans are recognized at the time of origination. We sell substantially all of the mortgages we originate and the related servicing rights to third-party purchasers. Interest income is earned from the date a mortgage loan is originated until the loan is sold and is classified within other income in the consolidated statements of operations.
Substantially all of the mortgage loans originated are sold within a short period of time in the secondary mortgage market on a servicing released, nonrecourse basis, which limits exposure to nonperformance by loan buyer counterparties although we remain liable for certain limited representations and warranties related to loan sales, such as non-compliance with defined loan origination or documentation standards, including misstatement in the loan documents, early payoff or default on payments. Mortgage investors could seek to have us buy back loans or compensate them for losses incurred on mortgages we have sold based on claims that we breached our limited representations and warranties. We have established reserves for probable losses.
Loan Commitments and Related Derivatives Loan Commitments and Related Derivatives
We are party to interest rate lock commitments (“IRLCs”), which are extended to borrowers who have applied for loan funding and meet defined credit and underwriting criteria in connection with our October 2018 acquisition of MLOA. IRLCs are accounted for as derivative instruments recorded at fair value with gains and losses recognized in revenue in the consolidated statements of operations. We manage our interest rate risk related to IRLCs and mortgage loans held for sale through the use of derivative instruments, generally forward contracts on mortgage-backed securities (“MBS”), which are commitments to either purchase or sell a specified financial instrument at a specified future date for a specified price, and mandatory loan commitments, which are an obligation by an investor to buy loans at a specified price within a specified time period. We do not enter into or hold derivatives for trading or speculative purposes and our derivatives are not designated as hedging instruments. Changes in the fair value of our derivative financial instruments are recognized in revenues in our consolidated statements of operations, and the fair values are reflected in other assets or other liabilities, as applicable. The net change in fair value was not significant for the year ended December 31, 2018.
There are no credit-risk-related contingent features within our derivative agreements, and counterparty risk is considered minimal. Gains and losses on IRLCs are substantially offset by corresponding gains or losses on forward contracts on mortgage-backed securities and mandatory loan commitments. We are generally not exposed to variability in cash flows of derivative instruments for more than approximately 90 days.
Inventory Inventory
Inventory is comprised of homes acquired through our Zillow Offers program and is stated at the lower of cost or net realizable value. Homes are removed from inventory on a specific identification basis when they are resold. Stated cost includes consideration paid to acquire and update each home including associated allocated overhead costs. Work-in-progress inventory includes homes undergoing updates and finished goods inventory includes homes ready for resale. Unallocated overhead costs are expensed as incurred and included in cost of revenue. Selling costs, including commissions, escrow and title fees, staging, and holding costs, including utilities, taxes and maintenance, are expensed as incurred and included in sales and marketing expenses.
Each quarter we review the value of homes held in inventory for indicators that net realizable value is lower than cost. When evidence exists that the net realizable value of inventory is lower than its cost, the difference is recognized in cost of revenue.
Property and Equipment Property and Equipment
Property and equipment is recorded at cost and depreciated using the straight-line method over the estimated useful lives of the related assets. The useful lives are as follows:
 
Computer equipment
  
2 to 3 years
Office equipment, furniture and fixtures
  
5 to 7 years
Leasehold improvements
  
Shorter of expected useful life or lease term

Maintenance and repair costs are charged to expense as incurred. Major improvements, which extend the useful life of the related asset, are capitalized. Upon disposal of a fixed asset, we record a gain or loss based on the difference between the proceeds received and the net book value of the disposed asset.
Website and Software Development Costs Website and Software Development Costs
The costs incurred in the preliminary stages of development are expensed as incurred. Once an application has reached the development stage, internal and external costs, if direct and incremental and deemed by management to be significant, are capitalized in property and equipment and amortized on a straight-line basis over their estimated useful lives. Maintenance and enhancement costs, including those costs in the post-implementation stages, are typically expensed as incurred, unless such costs relate to substantial upgrades and enhancements to the website or software that result in added functionality, in which case the costs are capitalized and amortized on a straight-line basis over the estimated useful lives. Amortization expense related to capitalized website and software development costs is included in technology and development expense.
Capitalized development activities placed in service are amortized over the expected useful lives of those releases, currently estimated at one to three years. The estimated useful lives of website and software development activities are reviewed frequently and adjusted as appropriate to reflect upcoming development activities that may include significant upgrades and/or enhancements to the existing functionality.
Recoverability of Goodwill and Indefinite-Lived Intangible Assets Recoverability of Goodwill and Indefinite-Lived Intangible Assets
Goodwill represents the excess of the cost of an acquired business over the fair value of the assets acquired at the date of acquisition, and is not amortized. We assess the impairment of goodwill on an annual basis, in our fourth quarter, or whenever events or changes in circumstances indicate that goodwill may be impaired. Typically, we choose to forgo the initial qualitative assessment and perform a quantitative analysis to assist in our annual evaluation. If impairment exists, the carrying value of the goodwill is reduced to fair value through an impairment charge recorded in our statements of operations.
Our indefinite-lived intangible asset is not amortized, and we assess the asset for impairment on an annual basis, in our fourth quarter, or whenever events or changes in circumstances indicate that the asset may be impaired. On an interim basis we consider if there are any events and circumstances that could affect the significant inputs used to determine the fair value of the indefinite-lived intangible asset, including, but not limited to, costs that could have a negative effect on future expected earnings and cash flows, changes in certain key performance metrics, and changes in management, key personnel, strategy or customers. In our evaluation of our trade names and trademarks indefinite-lived intangible asset, we typically first perform a qualitative assessment to determine whether the fair value of the indefinite-lived intangible asset is more likely than not impaired. If so, we perform a quantitative assessment and an impairment charge is recorded in our statements of operations for the excess of the carrying value of the indefinite-lived intangible asset over its fair value.
Intangible Assets/Recoverability of Intangible Assets with Definite Lives and Other Long-Lived Assets Intangible Assets
We purchase and license data content from multiple data providers. This data content consists of U.S. county data about home details (e.g., the number of bedrooms, bathrooms, square footage) and other information relating to the purchase price of homes, both current and historical, as well as imagery, mapping and parcel data that is displayed on our mobile applications and websites. Our home details data not only provides information about a home and its related transactions which is displayed on our mobile applications and websites, but is also used in our proprietary valuation algorithms to produce Zestimates, Rent Zestimates and Zillow Home Value Indexes. License agreement terms vary by vendor. In some instances, we retain perpetual rights to this information after the contract ends; in other instances, the information and data are licensed only during the fixed term of the agreement. Additionally, certain data license agreements provide for uneven payment amounts throughout the contract term.
We capitalize payments made to third parties for data licenses that we expect to provide future economic benefit through the recovery of the costs of these arrangements via the generation of our revenue and margins. For data license contracts that include uneven payment amounts, we capitalize the payments as they are made as an intangible asset and the total contract value is typically amortized on a straight-line basis over the term of the contract, which is equivalent to the estimated useful life of the asset. We evaluate data content contracts for potential capitalization at the inception of the arrangement as well as each time periodic payments to third parties are made.
The amortization period for the capitalized purchased content is based on our best estimate of the useful life of the asset, which is approximately five years. The determination of the useful life includes consideration of a variety of factors including, but not limited to, our assessment of the expected use of the asset and contractual provisions that may limit the useful life, as well as an assessment of when the data is expected to become obsolete based on our estimates of the diminishing value of the data over time. We evaluate the useful life of the capitalized purchased data content each reporting period to determine whether events and circumstances warrant a revision to the remaining useful life. If we determine the estimate of the asset’s useful life requires modification, the carrying amount of the asset is amortized prospectively over the revised useful life. The capitalized purchased data content is amortized on a straight-line basis as the pattern of delivery of the economic benefits of the data cannot reliably be determined because we do not have the ability to reliably predict future traffic to our mobile applications and websites.
Under certain other data agreements, the underlying data is obtained on a subscription basis with consistent monthly or quarterly recurring payment terms over the contractual period. Upon the expiration of such arrangements, we no longer have the right to access the related data, and therefore, the costs incurred under such contracts are not capitalized and are expensed as payments are made. We would immediately lose rights to data under these arrangements if we were to cancel the subscription and/or cease making payments under the subscription arrangements.
We also capitalize costs related to the license of certain internal-use software from third parties, including certain licenses of software in cloud computing arrangements. Additionally, we capitalize costs incurred during the application development stage related to the development of internal-use software and enterprise cloud computing services. We expense costs as incurred related to the planning and post-implementation phases of development. Capitalized internal-use software costs are amortized over the estimated useful life of the asset, which is currently one to 3 years, on a straight-line basis.
Intangibles-in-progress consist of purchased content and software that are capitalizable but have not been placed in service.
We also have intangible assets for developed technology, customer relationships, trade names and trademarks and advertising relationships which we recorded in connection with acquisitions. Purchased intangible assets with a determinable economic life are carried at cost, less accumulated amortization. These intangible assets are amortized over the estimated useful life of the asset on a straight-line basis.
Recoverability of Intangible Assets with Definite Lives and Other Long-Lived Assets
We evaluate intangible assets and other long-lived assets for impairment whenever events or circumstances indicate that they may not be recoverable. Recoverability is measured by comparing the carrying amount of an asset group to future undiscounted net cash flows expected to be generated. We group assets for purposes of such review at the lowest level for which identifiable cash flows of the asset group are largely independent of the cash flows of the other groups of assets and liabilities. If this comparison indicates impairment, the amount of impairment to be recognized is calculated as the difference between the carrying value and the fair value of the asset group.
Contract Cost Assets/Revenue Recognition Contract Cost AssetsWe capitalize certain incremental costs of obtaining contracts with customers which we expect to recover. These costs relate to commissions paid to sales personnel, primarily for our Premier Agent and Premier Broker programs. As a practical expedient, we recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that we otherwise would have recognized is one year or less. Capitalized commission costs are recorded as contract cost assets in our consolidated balance sheets. Contract cost assets are amortized to expense on a straight-line basis over a period that is consistent with the transfer to the customer of the products or services to which the asset relates, generally the estimated life of the customer relationship. Amortization expense related to contract cost assets is included in sales and marketing expenses in our consolidated statements of operations. In determining the estimated life of our customer relationships, we consider quantitative and qualitative data, including, but not limited to, historical customer data, recent changes or expected changes in product or service offerings, and changes in how we monetize our products and services. The amortization period for capitalized contract costs related to our Premier Agent and Premier Broker programs ranges from two to three years.Revenue Recognition
We recognize revenue when (or as) we satisfy our performance obligations by transferring control of the promised products or services to our customers in an amount that reflects the consideration to which we expect to be entitled in exchange for those products or services.
As a practical expedient, we do not adjust the promised amount of consideration for the effects of a significant financing component as the period between our transfer of a promised product or service to a customer and when the customer pays for that product or service is one year or less.
We do not disclose the transaction price related to remaining performance obligations for (i) contracts with an original expected duration of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for performance completed to date. The remaining duration of our performance obligations is generally less than one year.
In our Internet, Media & Technology (“IMT”) segment, we generate revenue from the sale of advertising services and our suite of marketing software and technology solutions to businesses and professionals primarily associated with the residential real estate, rental and mortgage industries. These professionals include real estate, rental and mortgage professionals and brand advertisers. Our four primary revenue categories within our IMT segment are Premier Agent, Rentals, Mortgages and Other.
In our Homes segment, we generate revenue from the resale of homes on the open market through our Zillow Offers program.
Premier Agent Revenue. Premier Agent revenue is derived from our Premier Agent and Premier Broker programs. Our Premier Agent and Premier Broker programs offer a suite of marketing and business technology products and services to help real estate agents and brokers achieve their advertising goals, while growing and managing their businesses and brands. All Premier Agents and Premier Brokers receive access to a dashboard portal on our mobile application or website that provides individualized program performance analytics, our customer relationship management, or CRM, tool that captures detailed information about each contact made with a Premier Agent or Premier Broker through our mobile and web platforms and our account management tools. We have concluded that the marketing and business technology products and services promised to Premier Agents and Premier Brokers represent distinct performance obligations.
We primarily offer our Premier Agent and Premier Broker advertising products on a cost per impression basis. Payment is received prior to the delivery of impressions. Impressions are delivered when a sold advertisement appears on pages viewed by users of our mobile applications and websites. We determine the cost per impression delivered in each zip code using an auction-based pricing method in consideration of the total amount spent by Premier Agents and Premier Brokers to purchase impressions in the zip code during the month. A Premier Agent’s or Premier Broker’s share of voice in a zip code is determined by their proportional monthly budgeted spend in that zip code as a percentage of the total monthly budgeted spend of all Premier Agents and Premier Brokers in that zip code. The cost per impression that we charge is dynamic - as demand for impressions in a zip code increases or decreases, the cost per impression in that zip code may be increased or decreased accordingly. The price paid for each impression is representative of the price at which we would sell an impression separately to a customer, or the stand-alone selling price.
We have not allocated the transaction price to each performance obligation as the amounts recognized would be the same irrespective of any allocation. As such, we recognize revenue related to the Premier Agent and Premier Broker products and services based on the contractual spend recognized on a straight-line basis during the contractual period over which the
products and services are provided. This methodology best depicts how we satisfy our performance obligations to customers, as we continuously transfer control of the performance obligations to the customer throughout the contractual period.
In October 2018, we began testing a new Flex Pricing model for Premier Broker and Premier Agent advertising services in limited markets. With the Flex Pricing model, Premier Brokers and Premier Agents are provided with validated leads at no upfront cost, and they pay a performance advertising fee only when a real estate transaction is closed with one of their leads. With this pricing model, the transaction price represents variable consideration as the amount to which we expect to be entitled varies based on the number of validated leads that convert into real estate transactions.
Rentals Revenue. Rentals revenue includes our rentals marketplace and suite of tools for rental professionals. Rentals revenue primarily includes revenue generated by advertising sold to property managers and other rental professionals on a cost per lead, cost per click or cost per lease generated basis. We recognize revenue as leads or clicks are provided to rental professionals, which is the amount for which we have the right to invoice. The number of leases generated through our rentals marketplace during the period is accounted for as variable consideration, and we estimate these amounts based on the expected number of qualified leases secured during the period. We do not believe that a significant reversal in the amount of cumulative revenue recognized will occur once the uncertainty related to the number of leases secured is subsequently resolved.
Beginning in 2018, rentals revenue also includes revenue generated from Zillow’s rental applications product through which potential renters can submit applications to multiple rental properties over a 30-day period for a flat service fee. We recognize revenue for the rental applications product on a straight-line basis during the contractual period over which the customer has the right to access and submit the rental application.
Mortgages Revenue. Mortgages revenue primarily includes marketing products sold to mortgage professionals on a cost per lead basis, including our Custom Quote and a portion of our Connect (formerly known as Long Form) services, and on a subscription basis, including a portion of our Connect service. For our Connect and Custom Quote cost per lead mortgage marketing products, participating qualified mortgage professionals typically make a prepayment to gain access to consumers interested in connecting with mortgage professionals. Mortgage professionals who exhaust their initial prepayment prepay additional funds to continue to participate in the marketplace. For our Connect subscription mortgage marketing product, participating qualified mortgage professionals generally prepay a monthly subscription fee, which they then allocate to desired geographic counties. In Zillow Group’s Connect platform, consumers answer a series of questions to find a local lender, and mortgage professionals receive consumer contact information, or leads, when the consumer chooses to share their information with a lender. Consumers who request rates for mortgage loans in Custom Quotes are presented with customized quotes from participating mortgage professionals.
For our cost per lead mortgages products, we recognize revenue when a user contacts a mortgage professional through Zillow Group’s mortgages platform, which is the amount for which we have the right to invoice. For our Connect subscription product, the opportunity to receive a consumer contact is based on the mortgage professional’s relative share of voice in a geographic county. When a consumer submits a contact, Zillow Group contacts a group of subscription mortgage professionals via text message, and the first mortgage professional to respond receives the consumer contact information. We recognize revenue based on the contractual spend recognized on a straight-line basis during the contractual period over which the service is provided. This methodology best depicts how we satisfy our performance obligation to subscription customers, as we continuously transfer control of the performance obligation to the customer throughout the contractual period.
Beginning in October 2018, mortgages revenue also includes revenue generated from our mortgage originations business. We elect the fair value option for our mortgage loans held for sale, which are initially recorded at fair value based on either sale commitments or current market quotes and are adjusted for subsequent changes in fair value until the loans are closed.
Mortgages revenue also includes revenue generated by Mortech, which provides subscription-based mortgage software solutions, including a product and pricing engine and lead management platform, for which we recognize revenue on a straight-line basis during the contractual period over which the services are provided.
Other Revenue. Other revenue primarily includes revenue generated by new construction and display, as well as revenue from the sale of various other marketing and business products and services to real estate professionals. Our new construction marketing solutions allow home builders to showcase their available inventory to home shoppers. New construction revenue primarily includes revenue generated by advertising sold to builders on a cost per residential community basis, and revenue is recognized on a straight-line basis during the contractual period over which the communities are advertised on our mobile applications and websites. Consideration is billed in arrears. Display revenue primarily consists of graphical mobile and web advertising sold on a cost per thousand impressions or cost per click basis to advertisers promoting their brands on our mobile
applications and websites. We recognize display revenue as clicks occur or as impressions are delivered to users interacting with our mobile applications or websites, which is the amount for which we have the right to invoice.
Homes Revenue. Homes revenue is derived from the resale of homes on the open market through our Zillow Offers program. Homes revenue is recognized at the time of the closing of the home sale when title to and possession of the property are transferred to the buyer.
There were no customers that generated 10% or more of our total revenue in the years ended December 31, 2018, 2017 or 2016.
Cost of Revenue
For our IMT segment, our cost of revenue consists of expenses related to operating our mobile applications and websites, including associated headcount expenses, such as salaries and benefits and share-based compensation expense and bonuses, as well as credit card fees, ad serving costs paid to third parties, revenue-sharing costs related to our commercial business relationships, depreciation expense and costs associated with the operation of our data center and mobile applications and websites. Beginning in the fourth quarter of 2018, cost of revenue within the IMT segment also includes expenses associated with our mortgage originations business, such as origination costs and fees, lead acquisition costs and expenses related to systems used directly in the origination of mortgages. For our Homes segment, our cost of revenue also consists of the consideration paid to acquire and make necessary updates to each home including associated overhead costs. Deferred RevenueDeferred revenue consists of prepaid advertising fees received or billed in advance of satisfying our performance obligations and prepaid but unrecognized subscription revenue. Deferred revenue is recognized when or as we satisfy our obligations under contracts with customers.
Deferred Rent Deferred RentFor our operating leases, we recognize rent expense on a straight-line basis over the terms of the leases and, accordingly, we record the difference between cash rent payments and the recognition of rent expense as a deferred rent liability. For office space under an operating lease that is subleased to a third party for which we intend to reoccupy the space at a future date, rent expense is recognized net of sublease income. Landlord-funded leasehold improvements are also recorded as deferred rent liabilities and are amortized as a reduction of rent expense over the non-cancelable term of the related operating lease.
Business Combinations Business CombinationsWe recognize identifiable assets acquired and liabilities assumed at their acquisition date fair values. Goodwill as of the acquisition date is measured as the excess of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. While we use our best estimates and assumptions for the purchase price allocation process to value assets acquired and liabilities assumed at the acquisition date, our estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, we record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill to the extent that we identify adjustments to the preliminary purchase price allocation. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to our consolidated statements of operations. We recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined.
Technology and Development Technology and Development
Technology and development expenses consist of headcount expenses, including salaries, benefits, share-based compensation expense and bonuses for salaried employees and contractors engaged in the design, development and testing of our mobile applications and websites and the tools and applications that support our products, and equipment and maintenance costs. Technology and development expenses also include amortization costs related to capitalized website and development activities, amortization of software, amortization of certain intangibles and other data agreement costs related to the purchase of data used to populate our mobile applications and websites, amortization of intangible assets recorded in connection with acquisitions, including developed technology and customer relationships, amongst others, and depreciation expense.
Research and development costs are expensed as incurred and are recorded in technology and development expenses.
Share-Based Compensation Share-Based Compensation
We measure compensation expense for all share-based awards at fair value on the date of grant and recognize compensation expense over the service period on a straight-line basis for awards expected to vest.
We use the Black-Scholes-Merton option-pricing model to determine the fair value for option awards. In valuing our option awards, we make assumptions about risk-free interest rates, dividend yields, volatility, and weighted-average expected lives. In addition, through December 31, 2016, we made assumptions about estimated forfeiture rates. Beginning on January 1, 2017, we elected to account for forfeitures as they occur. Risk-free interest rates are derived from U.S. Treasury securities as of the option award grant date. Expected dividend yield is based on our historical cash dividend payments, which have been zero to date. The expected volatility for our Class A common stock and Class C capital stock is estimated using our historical volatility. The weighted-average expected life of the option awards is estimated based on our historical exercise data. Prior to January 1, 2017, forfeiture rates were estimated using historical actual forfeiture trends as well as our judgment of future forfeitures. These rates were evaluated at least quarterly and any change in share-based compensation expense was recognized in the period of the change. We considered many factors when estimating expected forfeitures, including employee class and historical experience.
For issuances of restricted stock units and restricted units, we determine the fair value of the award based on the market value of our Class A common stock or Class C capital stock, as applicable, at the date of grant.
Advertising Costs Advertising costs are recorded in sales and marketing expenses.Advertising CostsAdvertising costs are expensed as incurred.
Income Taxes Income Taxes
We use the asset and liability approach for accounting and reporting income taxes, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement and tax bases of assets and liabilities at the applicable enacted tax rates. A valuation allowance against deferred tax assets would be established if, based on the weight of available evidence, it is more likely than not (a likelihood of more than 50%) that some or all of the deferred tax assets are not expected to be realized.
We establish reserves for tax-related uncertainties based on estimates of whether, and the extent to which, additional taxes will be due. We adjust these reserves in light of changing facts and circumstances, such as the closing of a tax audit, new tax legislation or the change of an estimate. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will affect the provision for income taxes in the period in which such determination is made. Interest and penalties related to unrecognized tax benefits are recorded as income tax expense.
On December 22, 2017, the U.S. government enacted comprehensive tax legislation under the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code, including but not limited to: (1) reducing the U.S. federal corporate tax rate from 35 percent to 21 percent; (2) requiring companies to pay a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries; (3) generally eliminating U.S. federal income taxes on dividends from foreign subsidiaries; (4) eliminating the corporate alternative minimum tax (“AMT”) and how AMT credits are utilized; (5) the additional limitations on deducting executive compensation under IRC Section 162(m); and (6) changing rules related to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017. Shortly after enactment, implementation guidance was released by the Securities and Exchange Commission that requires a company to reflect the income tax effects of those aspects of the Tax Act for which the accounting under the accounting rules is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete but the company is able to determine a reasonable estimate, it should record a provisional estimate in the financial statements. Further, the implementation guidance also provides for a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete their accounting pursuant to the accounting rules.
Recently Adopted Accounting Standards Recently Adopted Accounting Standards
In December 2016, the Financial Accounting Standards Board (“FASB”) issued guidance to narrow the definition of a business. This guidance assists entities with evaluating when a set of transferred assets and activities is a business. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, and early adoption is permitted. This guidance must be applied prospectively to transactions occurring within the period of adoption. We adopted this guidance on January 1, 2018. The adoption of this guidance did not have an impact on our financial position, results of operations or cash flows.
In January 2016, the FASB issued guidance on the recognition and measurement of financial instruments. This guidance generally requires equity investments, except those accounted for under the equity method of accounting or those that result in consolidation of the investee, to be measured at fair value with changes in fair value recognized in net income (loss). An entity may elect to measure equity securities that do not have readily determinable fair values and do not qualify for the net asset value per share practical expedient at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. The guidance also requires the separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, early adoption is permitted, and the guidance must be applied prospectively to equity investments that exist as of the adoption date. We adopted this guidance, and the February 2018 amendment to this guidance, effective January 1, 2018. The adoption of this guidance did not have any impact on our financial position, results of operations or cash flows.
In May 2014, the FASB issued guidance on revenue from contracts with customers. The guidance states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those products or services. It also states that an entity should recognize as an asset the incremental costs of obtaining a contract that the entity expects to recover and amortize the costs consistent with the transfer to the customer of the products or services to which the asset relates. The guidance requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. We adopted this guidance effective January 1, 2018 using the modified retrospective transition approach applied to all contracts at the date of initial application. We recorded an adjustment of $40.3 million to decrease accumulated deficit as of January 1, 2018 related to the accounting for the cost of sales commissions, primarily related to sales commissions for our Premier Agent and Premier Broker advertising products.
Historically, we expensed these sales commission costs as incurred, but under the new guidance, the cost of certain sales commissions is recorded as a contract cost asset and recognized as an operating expense over the period that we expect to recover the costs.
The amount by which each financial statement line item is affected by the application of this guidance as of and for the year ended December 31, 2018 is as follows (in thousands, except per share data):
 
 
New Guidance
 
Prior Guidance
 
Change
Consolidated Statement of Operations:
 
 
 
 
 
 
Sales and marketing
 
$
552,621

 
$
558,118

 
$
(5,497
)
Total costs and expenses
 
1,462,529

 
1,468,026

 
(5,497
)
Loss from operations
 
(128,975
)
 
(134,472
)
 
5,497

Loss before income taxes
 
(150,960
)
 
(156,457
)
 
5,497

Income tax benefit
 
31,102

 
32,024

 
(922
)
Net loss
 
(119,858
)
 
(124,433
)
 
4,575

Net loss per share — basic and diluted
 
(0.61
)
 
(0.63
)
 
0.02

Consolidated Balance Sheet:
 
 
 
 
 

Contract cost assets
 
45,819

 

 
45,819

Total assets
 
4,291,116

 
4,245,297

 
45,819

Deferred tax liabilities and other long-term liabilities
 
17,474

 
16,552

 
922

Total liabilities
 
1,023,937

 
1,023,015

 
922

Accumulated deficit
 
(671,779
)
 
(716,676
)
 
44,897

Total shareholders’ equity
 
3,267,179

 
3,222,282

 
44,897

Total liabilities and shareholders’ equity
 
$
4,291,116

 
$
4,245,297

 
$
45,819


Recently Issued Accounting Standards Not Yet Adopted
In August 2018, the FASB issued guidance related to a customer’s accounting for implementation costs incurred in hosting arrangements. The guidance aligns the requirements for capitalizing implementation costs incurred in cloud computing arrangements with the requirements for capitalizing costs to develop or obtain internal-use software. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, and early adoption is permitted. This guidance may be applied either retrospectively or prospectively. We expect to adopt this guidance on January 1, 2020. We have not yet determined the impact the adoption of this guidance will have on our financial position, results of operations or cash flows.
In August 2018, the FASB issued guidance related to disclosure requirements for fair value measurements. This guidance removes, modifies and adds disclosures related to fair value measurements. This guidance is effective for interim and annual periods beginning after December 15, 2019, and early adoption is permitted. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim and annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. We expect to adopt this guidance on January 1, 2020. We have not yet determined the impact the adoption of this guidance will have on our financial statement disclosures.
In June 2018, the FASB issued guidance related to contributions received and made. This guidance assists entities with evaluating whether a transfer of assets is considered a contribution or an exchange transaction. This guidance is effective for interim and annual reporting periods beginning after June 15, 2018 for contributions received and after December 15, 2018 for contributions made, and early adoption is permitted. The guidance should be applied on a modified prospective basis, though retrospective application is permitted. We adopted this guidance on January 1, 2019. The adoption of this guidance is not expected to have a material impact on our financial position, results of operations or cash flows.
In February 2018, the FASB issued guidance on income tax accounting related to the Tax Act. This guidance permits a reclassification from accumulated other comprehensive income (loss) to accumulated deficit for the adjustment of deferred taxes due to the reduction of the historical corporate income tax rate to the newly enacted corporate income tax rate under the Tax Act. It also requires certain disclosures regarding these reclassifications. The guidance is effective for interim and annual reporting periods beginning after December 15, 2018, and early adoption is permitted. This guidance must be applied either on a prospective basis in the period of adoption or retrospectively to each period in which the effect of the change in the corporate income tax rate is recognized. We adopted this guidance on January 1, 2019. The adoption of this guidance is not expected to have a material impact on our financial position, results of operations or cash flows.
In March 2017, the FASB issued guidance related to the premium amortization on purchased callable debt securities. This guidance shortens the amortization period for certain callable debt securities purchased at a premium by requiring that the premium be amortized to the earliest call date. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018, and early adoption is permitted. This guidance must be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. We adopted this guidance on January 1, 2019. The adoption of this guidance is not expected to have a material impact on our financial position, results of operations or cash flows.
In June 2016, the FASB issued guidance on the measurement of credit losses on financial instruments. This guidance requires the use of an expected loss impairment model for instruments measured at amortized cost. For available-for-sale debt securities, an entity is required to recognize credit losses through an allowance for credit losses rather than as a write-down. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019, and early adoption is permitted for interim and annual reporting periods beginning after December 15, 2018. The adoption of this guidance requires a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. We expect to adopt this guidance on January 1, 2020. We have not yet determined the impact the adoption of this guidance will have on our financial position, results of operations or cash flows.
In February 2016, the FASB issued guidance on leases. This guidance requires the recognition of a right-of-use asset and lease liability on the balance sheet for all leases. This guidance also requires more detailed disclosures to enable users of financial statements to understand the amount, timing, and uncertainty of cash flows arising from leases. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018. In July 2018, the FASB issued certain targeted improvements to the accounting and disclosure requirements for leases, including an additional optional transition method that allows entities to initially apply the new standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption without restating prior periods. When adopting the lease guidance, an entity may elect a practical expedient package, under which it need not reassess (a) whether any expired or existing contracts are or contain leases; (b) the lease classification for any expired or existing leases; and (c) initial direct costs for any existing leases. These three practical expedients must be elected as a package and must be consistently applied to all existing leases at the date of adoption. We adopted the new guidance on leases on January 1, 2019 using the optional transition method and electing to adopt the practical expedient package. Under this approach, we will not restate the prior financial statements presented. Based on our lease portfolio as of December 31, 2018, we anticipate recording on our consolidated balance sheet right-of-use assets of approximately $90 million as well as operating lease liabilities of approximately $115 million with no material impact to our consolidated statements of operations or cash flows.
Fair Value Accounting standards define fair value as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market in an orderly transaction between market participants on the measurement date. The standards also establish a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There are three levels of inputs that may be used to measure fair value:
 
Level 1—Quoted prices in active markets for identical assets or liabilities.
Level 2—Assets and liabilities valued based on observable market data for similar instruments, such as quoted prices for similar assets or liabilities.
Level 3—Unobservable inputs that are supported by little or no market activity; instruments valued based on the best available data, some of which is internally developed, and considers risk premiums that a market participant would require.
We applied the following methods and assumptions in estimating our fair value measurements:
Cash equivalents—The fair value measurement of money market funds is based on quoted market prices in active markets. The fair value measurement of corporate notes and bonds, commercial paper, U.S. government agency securities and certificates of deposit is based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means.
Short-term investments—The fair value measurement of our short-term investments is based on observable market-based inputs or inputs that are derived principally from or corroborated by observable market data by correlation or other means.
Restricted cash—The carrying value of restricted cash approximates fair value due to the short period of time amounts borrowed on the Revolving Credit Facility (see Note 14) are outstanding. Further, the carrying value of restricted cash related to escrow amounts held as part of the mortgage originations business also approximates fair value due to the short period of time amounts are held in escrow before they are transferred to the appropriate party, typically a home seller or bank.
Mortgage loans held for sale—The fair value of mortgage loans held for sale is generally calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics.
Interest rate lock commitments—The fair value of interest rate lock commitments is calculated by reference to quoted prices in secondary markets for commitments to sell mortgage loans with similar characteristics. Any expired commitments are excluded from the fair value measurement. We generally only issue IRLCs for products that meet specific purchaser guidelines. Since not all IRLCs will become closed loans, we adjust our fair value measurements for the estimated amount of IRLCs that will not close.
Forward contracts—The fair value of mandatory loan sales commitments and derivative instruments such as forward sales of MBS that are utilized as hedging instruments are calculated by reference to quoted prices for similar assets.
Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of shares (including Class A common stock, Class B common stock and Class C capital stock) outstanding during the period. In the calculation of basic net loss per share, undistributed earnings are allocated assuming all earnings during the period were distributed.Diluted net loss per share is computed by dividing net loss by the weighted-average number of shares (including Class A common stock, Class B common stock and Class C capital stock) outstanding during the period and potentially dilutive Class A common stock and Class C capital stock equivalents, except in cases where the effect of the Class A common stock or Class C capital stock equivalent would be antidilutive. Potential Class A common stock and Class C capital stock equivalents consist of Class A common stock and Class C capital stock issuable upon exercise of stock options and Class A common stock and Class C capital stock underlying unvested restricted stock awards and unvested restricted stock units using the treasury stock method. Potential Class A common stock equivalents also include Class A common stock issuable upon conversion of the 2020 Notes using the if-converted method.
Segment Information and Revenue Beginning in the second quarter of 2018, we have two operating and reportable segments, which have been identified based on the way in which our chief operating decision-maker manages our business, makes operating decisions and evaluates operating performance. Our chief executive officer acts as the chief operating decision-maker and reviews financial and operational information of the IMT and Homes segments.
The IMT segment includes the financial results for the Premier Agent, Rentals, Mortgages and new construction marketplaces, dotloop, and display, as well as revenue from the sale of various other marketing and business products and services to real estate professionals. The Homes segment includes the financial results from Zillow Group’s buying and selling of homes directly.
Revenue and costs are generally directly attributed to our segments. However, due to the integrated structure of our business, certain costs incurred by one segment may benefit the other segment. These costs are generally headcount-related and are allocated to each segment based on the estimated effort attributable to each segment.
v3.10.0.1
Summary of Significant Accounting Policies (Tables)
12 Months Ended
Dec. 31, 2018
Accounting Policies [Abstract]  
Useful Lives Property and equipment is recorded at cost and depreciated using the straight-line method over the estimated useful lives of the related assets. The useful lives are as follows:
 
Computer equipment
  
2 to 3 years
Office equipment, furniture and fixtures
  
5 to 7 years
Leasehold improvements
  
Shorter of expected useful life or lease term
Schedule of Effect of Application of New Guidance The amount by which each financial statement line item is affected by the application of this guidance as of and for the year ended December 31, 2018 is as follows (in thousands, except per share data):
 
 
New Guidance
 
Prior Guidance
 
Change
Consolidated Statement of Operations:
 
 
 
 
 
 
Sales and marketing
 
$
552,621

 
$
558,118

 
$
(5,497
)
Total costs and expenses
 
1,462,529

 
1,468,026

 
(5,497
)
Loss from operations
 
(128,975
)
 
(134,472
)
 
5,497

Loss before income taxes
 
(150,960
)
 
(156,457
)
 
5,497

Income tax benefit
 
31,102

 
32,024

 
(922
)
Net loss
 
(119,858
)
 
(124,433
)
 
4,575

Net loss per share — basic and diluted
 
(0.61
)
 
(0.63
)
 
0.02

Consolidated Balance Sheet:
 
 
 
 
 

Contract cost assets
 
45,819

 

 
45,819

Total assets
 
4,291,116

 
4,245,297

 
45,819

Deferred tax liabilities and other long-term liabilities
 
17,474

 
16,552

 
922

Total liabilities
 
1,023,937

 
1,023,015

 
922

Accumulated deficit
 
(671,779
)
 
(716,676
)
 
44,897

Total shareholders’ equity
 
3,267,179

 
3,222,282

 
44,897

Total liabilities and shareholders’ equity
 
$
4,291,116

 
$
4,245,297

 
$
45,819

v3.10.0.1
Fair Value Measurements (Tables)
12 Months Ended
Dec. 31, 2018
Fair Value Disclosures [Abstract]  
Summary of Balances of Cash Equivalents and Investments The following tables present the balances of assets measured at fair value on a recurring basis, by level within the fair value hierarchy, as of the dates presented (in thousands):
 
December 31, 2018
 
Total
 
Level 1
 
Level 2
Cash equivalents:
 
 
 
 
 
Money market funds
$
541,575

 
$
541,575

 
$

Commercial paper
3,999

 

 
3,999

Short-term investments:
 
 
 
 
 
U.S. government agency securities
646,496

 

 
646,496

Corporate notes and bonds
112,933

 

 
112,933

Commercial paper
85,506

 

 
85,506

Municipal securities
39,306

 

 
39,306

Foreign government securities
14,915

 

 
14,915

Certificates of deposit
4,711

 

 
4,711

Mortgage origination-related:
 
 
 
 
 
Mortgage loans held for sale
35,409

 

 
35,409

Interest rate lock commitments
847

 

 
847

Forward contracts
(125
)
 

 
(125
)
Total
$
1,485,572

 
$
541,575

 
$
943,997

 
December 31, 2017
 
Total
 
Level 1
 
Level 2
Cash equivalents:
 
 
 
 
 
Money market funds
$
233,508

 
$
233,508

 
$

Corporate notes and bonds
6,199

 

 
6,199

Commercial paper
3,987

 

 
3,987

U.S. government agency securities
1,748

 

 
1,748

Certificates of deposit
249

 

 
249

Short-term investments:
 
 
 
 
 
U.S. government agency securities
298,758

 

 
298,758

Corporate notes and bonds
44,607

 

 
44,607

Commercial paper
39,325

 

 
39,325

Municipal securities
11,459

 

 
11,459

Certificates of deposit
10,297

 

 
10,297

Foreign government securities
5,998

 

 
5,998

Total
$
656,135

 
$
233,508

 
$
422,627

v3.10.0.1
Cash and Cash Equivalents, Short-term Investments and Restricted Cash (Tables)
12 Months Ended
Dec. 31, 2018
Cash and Cash Equivalents [Abstract]  
Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Market Value of Cash and Cash Equivalents and Short-term Investments The following tables present the amortized cost, gross unrealized gains and losses and estimated fair market value of our cash and cash equivalents, available-for-sale investments and restricted cash as of the dates presented (in thousands):
 
December 31, 2018
 
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Estimated
Fair
Market
Value
Cash
$
105,484

 
$

 
$

 
$
105,484

Cash equivalents:
 
 
 
 
 
 
 
Money market funds
541,575

 

 

 
541,575

Commercial paper
3,999

 

 

 
3,999

Short-term investments:
 
 
 
 
 
 
 
U.S. government agency securities
647,266

 
51

 
(821
)
 
646,496

Corporate notes and bonds
113,109

 
1

 
(177
)
 
112,933

Commercial paper
85,506

 

 

 
85,506

Municipal securities
39,316

 
23

 
(33
)
 
39,306

Foreign government securities
14,929

 

 
(14
)
 
14,915

Certificates of deposit
4,711

 
1

 
(1
)
 
4,711

Restricted cash
12,385

 

 

 
12,385

Total
$
1,568,280

 
$
76

 
$
(1,046
)
 
$
1,567,310

 
December 31, 2017
 
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Estimated
Fair
Market
Value
Cash
$
106,404

 
$

 
$

 
$
106,404

Cash equivalents:
 
 
 
 
 
 
 
Money market funds
233,508

 

 

 
233,508

Corporate notes and bonds
6,200

 

 
(1
)
 
6,199

Commercial paper
3,987

 

 

 
3,987

U.S. government agency securities
1,748

 

 

 
1,748

Certificates of deposit
249

 

 

 
249

Short-term investments:
 
 
 
 
 
 
 
U.S. government agency securities
299,814

 

 
(1,056
)
 
298,758

Corporate notes and bonds
44,661

 
1

 
(55
)
 
44,607

Commercial paper
39,325

 

 

 
39,325

Municipal securities
11,494

 

 
(35
)
 
11,459

Certificates of deposit
10,296

 
2

 
(1
)
 
10,297

Foreign government securities
6,000

 

 
(2
)
 
5,998

Total
$
763,686

 
$
3

 
$
(1,150
)
 
$
762,539

Available-for-Sale Investments by Contractual Maturity The following table presents available-for-sale investments by contractual maturity date as of December 31, 2018 (in thousands):
 
Amortized
Cost
 
Estimated Fair Market Value
Due in one year or less
$
801,828

 
$
800,827

Due after one year through two years
103,009

 
103,040

Total
$
904,837

 
$
903,867

v3.10.0.1
Accounts Receivable, Net (Tables)
12 Months Ended
Dec. 31, 2018
Receivables [Abstract]  
Accounts Receivable The following table presents the detail of accounts receivable as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Accounts receivable
$
61,134

 
$
51,334

Unbilled accounts receivable
9,787

 
8,403

Less: allowance for doubtful accounts
(4,838
)
 
(5,341
)
Accounts receivable, net
$
66,083

 
$
54,396

Allowance for Doubtful Accounts The following table presents the changes in the allowance for doubtful accounts for the periods presented (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Allowance for doubtful accounts:
 
 
 
 
 
Balance, beginning of period
$
5,341

 
$
1,337

 
$
3,378

Additions charged to expense
869

 
7,349

 
2,681

Less: write-offs, net of recoveries and other adjustments
(1,372
)
 
(3,345
)
 
(4,722
)
Balance, end of period
$
4,838

 
$
5,341

 
$
1,337

v3.10.0.1
Inventory (Tables)
12 Months Ended
Dec. 31, 2018
Inventory Disclosure [Abstract]  
Components of Net Inventory The components of inventory, net of applicable lower of cost or net realizable value write-downs, were as follows for the periods presented (in thousands):
 
December 31,
 
2018
 
2017
Work-in-progress
$
45,943

 
$

Finished goods
116,886

 

Inventory
$
162,829

 
$


We have not recorded any inventory write-downs for the years ended December 31, 2018 and 2017.
v3.10.0.1
Property and Equipment, Net (Tables)
12 Months Ended
Dec. 31, 2018
Property, Plant and Equipment [Abstract]  
Detail of Property and Equipment The following table presents the detail of property and equipment as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Website development costs
$
149,891

 
$
130,072

Computer equipment
22,477

 
30,071

Leasehold improvements
65,012

 
47,321

Construction-in-progress
29,037

 
28,150

Office equipment, furniture and fixtures
39,510

 
22,887

Property and equipment
305,927

 
258,501

Less: accumulated amortization and depreciation
(170,755
)
 
(146,230
)
Property and equipment, net
$
135,172

 
$
112,271

v3.10.0.1
Acquisitions and Equity Investments (Tables)
12 Months Ended
Dec. 31, 2018
Business Combinations [Abstract]  
Purchase Price Allocation Based upon the fair values determined by us, in which we considered or relied in part upon a valuation report of a third-party expert, the total purchase price was allocated as follows (in thousands):
Cash and cash equivalents
$
10,796

Restricted cash
753

Mortgage loans available for sale
34,248

Property, plant and equipment
1,315

Intangible assets
2,600

Goodwill
53,831

Other acquired assets
3,079

Accounts payable
(1,953
)
Accrued expenses
(2,591
)
Warehouse lines of credit
(32,536
)
Other assumed liabilities
(2,855
)
Total purchase price
$
66,687

Based upon the fair values determined by us, in which we considered or relied in part upon a valuation report of a third-party expert, the total purchase price was allocated as follows (in thousands):
Current assets
$
371

Identifiable intangible assets
3,700

Goodwill
10,610

Current liabilities
(101
)
Deferred tax liabilities
(1,416
)
Total purchase price
$
13,164

v3.10.0.1
Goodwill (Tables)
12 Months Ended
Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]  
Change in Goodwill The following table presents the change in goodwill from December 31, 2017 through December 31, 2018 (in thousands):
Balance as of December 31, 2017
$
1,931,076

Goodwill recorded in connection with acquisition of MLOA
53,831

Balance as of December 31, 2018
$
1,984,907

v3.10.0.1
Intangible Assets (Tables)
12 Months Ended
Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]  
Intangible Assets The following tables present the detail of intangible assets subject to amortization as of the dates presented (in thousands):
 
December 31, 2018
 
Cost
 
Accumulated
Amortization
 
Net
Purchased content
$
42,110

 
$
(30,477
)
 
$
11,633

Software
24,296

 
(13,925
)
 
10,371

Customer relationships
103,900

 
(60,733
)
 
43,167

Developed technology
111,980

 
(72,788
)
 
39,192

Trade names and trademarks
4,900

 
(4,683
)
 
217

MLOA lender licenses
400

 
(17
)
 
383

Intangibles-in-progress
2,941

 

 
2,941

Total
$
290,527

 
$
(182,623
)
 
$
107,904

 
December 31, 2017
 
Cost
 
Accumulated
Amortization
 
Net
Purchased content
$
35,260

 
$
(20,480
)
 
$
14,780

Software
18,957

 
(8,899
)
 
10,058

Customer relationships
103,900

 
(46,365
)
 
57,535

Developed technology
113,380

 
(56,664
)
 
56,716

Trade names and trademarks
4,900

 
(3,943
)
 
957

Advertising relationships
9,000

 
(8,525
)
 
475

Intangibles-in-progress
2,190

 

 
2,190

Total
$
287,587

 
$
(144,876
)
 
$
142,711

Estimated Future Amortization Expense for Intangible Assets Estimated future amortization expense for intangible assets, including amortization related to future commitments (see Note 19), as of December 31, 2018 is as follows (in thousands):
2019
$
42,648

2020
39,420

2021
33,908

2022
5,480

2023
373

Total future amortization expense
$
121,829

v3.10.0.1
Accrued Expenses and Other Current Liabilities (Tables)
12 Months Ended
Dec. 31, 2018
Payables and Accruals [Abstract]  
Summary of accrued expenses and other current liabilities The following table presents the detail of accrued expenses and other current liabilities as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Accrued marketing and advertising
$
18,559

 
$
17,180

Accrued purchased content
4,256

 
5,984

Accrued estimated legal liabilities and legal fees
7,305

 
9,052

Merger consideration payable to former stockholders of certain acquired entities
5,904

 
5,904

Other accrued expenses and other current liabilities
27,077

 
23,253

Total accrued expenses and other current liabilities
$
63,101

 
$
61,373

v3.10.0.1
Deferred Revenue (Tables)
12 Months Ended
Dec. 31, 2018
Revenue from Contract with Customer [Abstract]  
Schedule of Change in Deferred Revenue The following table presents the change in deferred revenue for the period presented (in thousands):
 
Year Ended December 31, 2018
Balance as of January 1, 2018
$
31,918

Deferral of revenue
982,647

Less: Revenue recognized
(980,485
)
Balance as of December 31, 2018
$
34,080

v3.10.0.1
Debt (Tables)
12 Months Ended
Dec. 31, 2018
Debt Disclosure [Abstract]  
Outstanding Principal Amount and Carrying Value The following table presents the outstanding principal amount and carrying value of the 2021 Notes as of the dates presented (in thousands):
 
Outstanding
Principal
Amount
 
Unamortized
Debt Discount
and Debt
Issuance Costs
 
Carrying
Value
December 31, 2018
$
460,000

 
$
(65,355
)
 
$
394,645

December 31, 2017
$
460,000

 
$
(84,721
)
 
$
375,279

The following table presents the outstanding principal amount and carrying value of the 2023 Notes as of the date presented (in thousands):
 
Outstanding
Principal
Amount
 
Unamortized
Debt Discount
and Debt
Issuance Costs
 
Carrying
Value
December 31, 2018
$
373,750

 
$
(79,012
)
 
$
294,738

v3.10.0.1
Income Taxes (Tables)
12 Months Ended
Dec. 31, 2018
Income Tax Disclosure [Abstract]  
Components of Income Tax (Benefit) Expense The following table summarizes the components of our income tax (benefit) expense for the periods presented (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Current income tax expense
 
 
 
 
 
     Foreign
$
161

 
$

 
$

Total current income tax expense
161

 

 

Deferred income tax (benefit) expense
 
 
 
 
 
     Federal
(28,502
)
 
(84,238
)
 
(1,248
)
     State
(2,441
)
 
(5,348
)
 
1,378

     Foreign
(320
)
 

 

Total deferred income tax (benefit) expense
(31,263
)
 
(89,586
)
 
130

Total income tax (benefit) expense
$
(31,102
)
 
$
(89,586
)
 
$
130

Reconciliation of Federal Statutory Rate and Effective Tax Rate The following table presents a reconciliation of the federal statutory rate and our effective tax rate for the periods presented:
 
Year Ended December 31,
 
2018
 
2017
 
2016
Tax expense at federal statutory rate
(21.0
)%
 
(35.0
)%
 
(35.0
)%
State income taxes, net of federal tax benefit
(5.9
)
 
(4.4
)
 
(1.9
)
Nondeductible expenses

 
0.8

 
4.9

Share-based compensation
(16.5
)
 
(20.6
)
 
(0.2
)
IRC section 162(m)
1.0

 

 

Research and development credits
(8.4
)
 
(6.3
)
 
(1.5
)
Meals and entertainment
1.8

 

 

Return to provision adjustments
(4.2
)
 

 

Enactment of Tax Act
(1.9
)
 
(13.1
)
 

Other
0.4

 
2.2

 
(0.9
)
Valuation allowance
34.0

 
27.7

 
34.7

Effective tax rate
(20.7
)%
 
(48.7
)%
 
0.1
 %
Deferred Tax Assets and Liabilities The following table presents the significant components of our deferred tax assets and liabilities as of the dates presented (in thousands):
 
December 31,
 
2018
 
2017
Deferred tax assets:
 
 
 
Federal and state net operating loss carryforwards
$
259,629

 
$
234,316

Share-based compensation
55,280

 
47,655

Start-up and organizational costs
99

 
146

Research and development credits
48,805

 
35,793

Other tax credits
910

 
910

Accruals and reserves
3,000

 
2,729

Deferred rent
4,842

 
5,484

Other deferred tax assets
14,267

 
8,342

Total deferred tax assets
386,832

 
335,375

Deferred tax liabilities:
 
 
 
Website and software development costs
(14,685
)
 
(13,202
)
Goodwill
(598
)
 
(688
)
Intangible assets
(45,035
)
 
(69,241
)
Discount on 2021 Notes and 2023 Notes not deductible for tax
(31,450
)
 
(19,374
)
Depreciation and amortization
(888
)
 
(2,425
)
Total deferred tax liabilities
(92,656
)
 
(104,930
)
Net deferred tax assets before valuation allowance
294,176

 
230,445

Less: valuation allowance
(307,599
)
 
(274,810
)
Net deferred tax liabilities
$
(13,423
)
 
$
(44,365
)
Changes in Unrecognized Tax Benefits Changes for unrecognized tax benefits for the periods presented are as follows (in thousands):
Balance at January 1, 2016
$
13,980

Gross increases—prior and current period tax positions
2,619

Gross decreases—prior period tax positions
(1,204
)
Balance at December 31, 2016
$
15,395

Gross increases—current period tax positions
5,216

Gross increases—prior period tax positions
1,002

Balance at December 31, 2017
$
21,613

Gross increases—current period tax positions
6,421

Gross increases—prior period tax positions
591

Balance at December 31, 2018
$
28,625

v3.10.0.1
Shareholders' Equity (Tables)
12 Months Ended
Dec. 31, 2018
Equity [Abstract]  
Common and Capital Stock Reserved for Future Issuance The following shares of common and capital stock have been reserved for future issuance as of the dates presented:
 
December 31, 2018
 
December 31, 2017
Option awards outstanding
27,310,110

 
26,645,206

Restricted stock units outstanding
5,266,324

 
4,016,405

Class A common stock and Class C capital stock available for grant under 2011 Plan
3,675,082

 
5,076,898

Shares issuable upon conversion of outstanding Class B common stock
6,217,447

 
6,217,447

Total
42,468,963

 
41,955,956

v3.10.0.1
Share-Based Awards (Tables)
12 Months Ended
Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Summary of Option Award and Stock Appreciation Rights Activity The following table summarizes option award activity for the year ended December 31, 2018:
 
Number
of Shares
Subject to
Existing
Options
 
Weighted-
Average
Exercise
Price Per
Share
 
Weighted-
Average
Remaining
Contractual
Life (Years)
 
Aggregate
Intrinsic
Value
(in
thousands)
Outstanding at January 1, 2018
26,645,206

 
$
27.70

 
5.72
 
$
355,739

Granted
6,963,320

 
48.95

 

 

Exercised
(5,472,728
)
 
21.94

 

 

Forfeited or cancelled
(825,688
)
 
35.32

 

 

Outstanding at December 31, 2018
27,310,110

 
34.04

 
6.23
 
97,941

Vested and exercisable at December 31, 2018
15,287,932

 
29.73

 
4.72
 
75,867

Fair Value of Options Granted, Excluding Options Grant to Executives Estimated at Date of Grant Using Black Scholes Merton Option Pricing Model The fair value of options granted is estimated at the date of grant using the Black-Scholes-Merton option-pricing model, assuming no dividends and with the following assumptions for the periods presented: 
 
Year Ended December 31,
 
2018
 
2017
 
2016
Expected volatility
42% – 45%
 
45% – 49%
 
49% – 51%
Expected dividend yield
 
 
Risk-free interest rate
2.52% – 2.84%
 
1.67% – 2.06%
 
0.89% – 1.89%
Weighted-average expected life
4.50 – 5.00 years
 
4.25 – 4.75 years
 
3.75 – 4.25 years
Weighted-average fair value of options granted
$19.11
 
$14.51
 
$9.42
Summary of Restricted Stock Units Activity The following table summarizes activity for restricted stock units for the year ended December 31, 2018:
 
Restricted
Stock Units
 
Weighted-
Average Grant-
Date Fair
Value
Unvested outstanding at January 1, 2018
4,016,405

 
$
33.22

Granted
3,725,726

 
48.26

Vested
(1,740,134
)
 
35.63

Forfeited or cancelled
(735,673
)
 
39.59

Unvested outstanding at December 31, 2018
5,266,324

 
42.19

Effects of Share Based Compensation in Consolidated Statements of Operations The following table presents the effects of share-based compensation expense in our consolidated statements of operations during the periods presented (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Cost of revenue
$
4,127

 
$
3,884

 
$
3,550

Sales and marketing
22,942

 
22,735

 
23,320

Technology and development
56,673

 
39,938

 
31,466

General and administrative
65,342

 
47,014

 
48,582

 
$
149,084

 
$
113,571

 
$
106,918

v3.10.0.1
Net Loss Per Share (Tables)
12 Months Ended
Dec. 31, 2018
Earnings Per Share [Abstract]  
Antidilutive Securities Excluded from Computation of Earnings Per Share For the periods presented, the following Class A common stock and Class C capital stock equivalents were excluded from the calculations of diluted net loss per share because their effect would have been antidilutive (in thousands):
 
Year Ended December 31,
 
2018
 
2017
 
2016
Weighted-average Class A common stock and Class C capital stock option awards outstanding
22,736

 
27,998

 
19,993

Weighted-average Class A common stock and Class C capital stock restricted stock units outstanding
4,949

 
4,262

 
3,607

Class A common stock issuable upon conversion of the 2020 Notes
400

 
435

 
440

Total Class A common stock and Class C capital stock equivalents
28,085

 
32,695

 
24,040

v3.10.0.1
Commitments and Contingencies (Tables)
12 Months Ended
Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]  
Future Minimum Payments for All Operating Leases Future minimum payments for all operating leases as of December 31, 2018 are as follows (in thousands): 
2019
$
29,085

2020
38,060

2021
40,099

2022
37,721

2023
36,458

All future years
85,462

Total future minimum lease payments
$
266,885

Purchase Commitments for Content Related to Mobile Applications and Websites The amounts due for these non-cancelable purchase commitments and homes under contract as of December 31, 2018 are as follows (in thousands):
 
Purchase Obligations
 
Homes Under Contract
2019
$
64,124

 
$
88,943

2020
64,007

 

2021
32,735

 

Total future purchase commitments
$
160,866

 
$
88,943

v3.10.0.1
Segment Information and Revenue (Tables)
12 Months Ended
Dec. 31, 2018
Segment Reporting [Abstract]  
Revenue Categories This information is included in the following table for the period presented (in thousands): 
 
Year Ended December 31, 2018
 
IMT
 
Homes
 
Consolidated
Revenue:
 
 
 
 
 
Premier Agent
$
898,332

 
$

 
$
898,332

Rentals
134,587

 

 
134,587

Mortgages
80,046

 

 
80,046

Other
168,224

 

 
168,224

Homes

 
52,365

 
52,365

Total revenue
1,281,189

 
52,365

 
1,333,554

Costs and expenses:
 
 
 
 
 
Cost of revenue
104,330

 
49,260

 
153,590

Sales and marketing
534,038

 
18,583

 
552,621

Technology and development
389,539

 
21,279

 
410,818

General and administrative
238,727

 
23,426

 
262,153

Impairment costs
79,000

 

 
79,000

Acquisition-related costs
2,332

 

 
2,332

Integration costs
2,015

 

 
2,015

Total costs and expenses
1,349,981

 
112,548

 
1,462,529

Income (loss) from operations
(68,792
)
 
(60,183
)
 
(128,975
)
Other income
19,270

 

 
19,270

Interest expense
(39,078
)
 
(2,177
)
 
(41,255
)
Loss before income taxes
$
(88,600
)
 
$
(62,360
)
 
$
(150,960
)
v3.10.0.1
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Jan. 01, 2019
Oct. 01, 2017
Schedule Of Significant Accounting Policies [Line Items]          
Other than temporary impairment loss $ 0 $ 0      
Non-cash impairment of indefinite-lived intangible assets 79,000,000 174,000,000 $ 0    
Research and development expenses 410,818,000 319,985,000 255,583,000    
Advertising expenses 177,300,000 156,500,000 120,200,000    
Accounting Standards Update 2016-02 | Scenario, Forecast | Subsequent Event          
Schedule Of Significant Accounting Policies [Line Items]          
Right-to-use assets       $ 90,000,000  
Lease liability       $ 115,000,000  
Technology and Development          
Schedule Of Significant Accounting Policies [Line Items]          
Research and development expenses $ 298,100,000 193,000,000.0 $ 170,100,000    
Purchased content          
Schedule Of Significant Accounting Policies [Line Items]          
Useful life of capitalized purchased content asset 5 years        
Minimum | Software Development          
Schedule Of Significant Accounting Policies [Line Items]          
Expected useful lives 1 year        
Maximum | Software Development          
Schedule Of Significant Accounting Policies [Line Items]          
Expected useful lives 3 years        
Trulia          
Schedule Of Significant Accounting Policies [Line Items]          
Indefinite-lived intangible asset $ 108,000,000.0 177,000,000.0     $ 351,000,000.0
Trulia | Trade names and trademarks          
Schedule Of Significant Accounting Policies [Line Items]          
Non-cash impairment of indefinite-lived intangible assets $ 69,000,000.0 $ 174,000,000.0      
v3.10.0.1
Summary of Significant Accounting Policies - Useful Lives (Detail)
12 Months Ended
Dec. 31, 2018
Minimum | Computer equipment  
Property, Plant and Equipment [Line Items]  
Property and equipment (useful life) 2 years
Minimum | Office equipment, furniture and fixtures  
Property, Plant and Equipment [Line Items]  
Property and equipment (useful life) 5 years
Maximum | Computer equipment  
Property, Plant and Equipment [Line Items]  
Property and equipment (useful life) 3 years
Maximum | Office equipment, furniture and fixtures  
Property, Plant and Equipment [Line Items]  
Property and equipment (useful life) 7 years
v3.10.0.1
Summary of Significant Accounting Policies - Schedule of Application of Guidance (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Statement [Abstract]        
Sales and marketing $ 552,621 $ 448,201 $ 382,419  
Total costs and expenses 1,462,529 1,238,668 1,039,443  
Income (loss) from operations (128,975) (161,874) (192,854)  
Income (loss) before income taxes (150,960) (184,006) (220,308)  
Income tax benefit (expense) 31,102 89,586 (130)  
Net loss $ (119,858) $ (94,420) $ (220,438)  
Net loss per share-basic and diluted (usd per share) $ (0.61) $ (0.51) $ (1.22)  
Statement of Financial Position [Abstract]        
Contract cost assets $ 45,819      
Total assets 4,291,116 $ 3,230,517    
Deferred tax liabilities and other long-term liabilities 17,474 44,561    
Total liabilities 1,023,937 569,694    
Accumulated deficit (671,779) (592,243)    
Total shareholders’ equity 3,267,179 2,660,823 $ 2,533,587 $ 2,679,053
Total liabilities and shareholders’ equity 4,291,116 $ 3,230,517    
Calculated under Revenue Guidance in Effect before Topic 606        
Income Statement [Abstract]        
Sales and marketing 558,118      
Total costs and expenses 1,468,026      
Income (loss) from operations (134,472)      
Income (loss) before income taxes (156,457)      
Income tax benefit (expense) 32,024      
Net loss $ (124,433)      
Net loss per share-basic and diluted (usd per share) $ (0.63)      
Statement of Financial Position [Abstract]        
Contract cost assets $ 0      
Total assets 4,245,297      
Deferred tax liabilities and other long-term liabilities 16,552      
Total liabilities 1,023,015      
Accumulated deficit (716,676)      
Total shareholders’ equity 3,222,282      
Total liabilities and shareholders’ equity 4,245,297      
Difference between Revenue Guidance in Effect before and after Topic 606 | Revenue from Contracts with Customers        
Income Statement [Abstract]        
Sales and marketing (5,497)      
Total costs and expenses (5,497)      
Income (loss) from operations 5,497      
Income (loss) before income taxes 5,497      
Income tax benefit (expense) (922)      
Net loss $ 4,575      
Net loss per share-basic and diluted (usd per share) $ 0.02      
Statement of Financial Position [Abstract]        
Contract cost assets $ 45,819      
Total assets 45,819      
Deferred tax liabilities and other long-term liabilities 922      
Total liabilities 922      
Accumulated deficit 44,897      
Total shareholders’ equity 44,897      
Total liabilities and shareholders’ equity $ 45,819      
v3.10.0.1
Fair Value Measurements - Fair Value of Cash Equivalents and Investments (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short-term investments $ 903,867  
Mortgage loans held for sale 35,409  
Assets 1,485,572 $ 656,135
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Mortgage loans held for sale 0  
Assets 541,575 233,508
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Mortgage loans held for sale 35,409  
Assets 943,997 422,627
Money market funds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 541,575 233,508
Money market funds | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 541,575 233,508
Money market funds | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 0 0
Commercial paper    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 3,999 3,987
Short-term investments 85,506 39,325
Commercial paper | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 0 0
Short-term investments 0 0
Commercial paper | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 3,999 3,987
Short-term investments 85,506 39,325
U.S. government agency securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   1,748
Short-term investments 646,496 298,758
U.S. government agency securities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   0
Short-term investments 0 0
U.S. government agency securities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   1,748
Short-term investments 646,496 298,758
Corporate notes and bonds    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   6,199
Short-term investments 112,933 44,607
Corporate notes and bonds | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   0
Short-term investments 0 0
Corporate notes and bonds | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   6,199
Short-term investments 112,933 44,607
Municipal securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short-term investments 39,306 11,459
Municipal securities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short-term investments 0 0
Municipal securities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short-term investments 39,306 11,459
Foreign government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short-term investments 14,915 5,998
Foreign government securities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short-term investments 0 0
Foreign government securities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Short-term investments 14,915 5,998
Certificates of deposit    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   249
Short-term investments 4,711 10,297
Certificates of deposit | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   0
Short-term investments 0 0
Certificates of deposit | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents   249
Short-term investments 4,711 $ 10,297
Interest rate lock commitments | Not Designated as Hedging Instrument    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets 847  
Interest rate lock commitments | Level 1 | Not Designated as Hedging Instrument    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets 0  
Interest rate lock commitments | Level 2 | Not Designated as Hedging Instrument    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets 847  
Forward contracts | Not Designated as Hedging Instrument    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets (125)  
Forward contracts | Level 1 | Not Designated as Hedging Instrument    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets 0  
Forward contracts | Level 2 | Not Designated as Hedging Instrument    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivative assets $ (125)  
v3.10.0.1
Fair Value Measurements - Additional Information (Detail) - USD ($)
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Measurements, Recurring    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities measured at fair value $ 0 $ 0
Fair Value, Inputs, Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets measured at fair value 0 $ 0
Interest rate lock commitments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notional amounts of hedging instruments 26,700,000  
Forward contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Notional amounts of hedging instruments $ 28,800,000  
v3.10.0.1
Cash and Cash Equivalents, Short-term Investments and Restricted Cash - Amortized Cost, Gross Unrealized Gains and Losses, and Estimated Fair Market Value of Cash and Cash Equivalents and Short-term Investments (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Cash and Cash Equivalents, at Carrying Value [Abstract]    
Cash and cash equivalents $ 651,058 $ 352,095
Debt Securities, Available-for-sale [Abstract]    
Amortized Cost 904,837  
Gross Unrealized Gains 76 3
Gross Unrealized Losses (1,046)  
Estimated Fair Market Value 903,867  
Restricted cash 12,385  
Cash, cash equivalents, short-term investments, and restricted cash, amortized cost 1,568,280 763,686
Cash, cash equivalents, short-term investments, and restricted cash, gross unrealized losses   (1,150)
Cash, cash equivalents, short-term investments, and restricted cash, estimated fair market value 1,567,310 762,539
U.S. government agency securities    
Debt Securities, Available-for-sale [Abstract]    
Amortized Cost 647,266 299,814
Gross Unrealized Gains 51 0
Gross Unrealized Losses (821) (1,056)
Estimated Fair Market Value 646,496 298,758
Corporate notes and bonds    
Debt Securities, Available-for-sale [Abstract]    
Amortized Cost 113,109 44,661
Gross Unrealized Gains 1 1
Gross Unrealized Losses (177) (55)
Estimated Fair Market Value 112,933 44,607
Commercial paper    
Debt Securities, Available-for-sale [Abstract]    
Amortized Cost 85,506 39,325
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Estimated Fair Market Value 85,506 39,325
Municipal securities    
Debt Securities, Available-for-sale [Abstract]    
Amortized Cost 39,316 11,494
Gross Unrealized Gains 23 0
Gross Unrealized Losses (33) (35)
Estimated Fair Market Value 39,306 11,459
Certificates of deposit    
Debt Securities, Available-for-sale [Abstract]    
Amortized Cost 4,711 10,296
Gross Unrealized Gains 1 2
Gross Unrealized Losses (1) (1)
Estimated Fair Market Value 4,711 10,297
Foreign government securities    
Debt Securities, Available-for-sale [Abstract]    
Amortized Cost 14,929 6,000
Gross Unrealized Gains 0 0
Gross Unrealized Losses (14) (2)
Estimated Fair Market Value 14,915 5,998
Cash    
Cash and Cash Equivalents, at Carrying Value [Abstract]    
Cash and cash equivalents 105,484 106,404
Money market funds    
Cash and Cash Equivalents, at Carrying Value [Abstract]    
Cash and cash equivalents 541,575 233,508
Commercial paper    
Cash and Cash Equivalents, at Carrying Value [Abstract]    
Cash and cash equivalents $ 3,999 3,987
U.S. government agency securities    
Cash and Cash Equivalents, at Carrying Value [Abstract]    
Cash and cash equivalents   1,748
Corporate notes and bonds    
Cash and Cash Equivalents, at Carrying Value [Abstract]    
Cash and cash equivalents, at cost   6,200
Cash and cash equivalents, gross unrealized losses   (1)
Cash and cash equivalents   6,199
Certificates of deposit    
Cash and Cash Equivalents, at Carrying Value [Abstract]    
Cash and cash equivalents   $ 249
v3.10.0.1
Cash and Cash Equivalents, Short-term Investments and Restricted Cash - Available-for-Sale Investments by Contractual Maturity (Detail)
$ in Thousands
Dec. 31, 2018
USD ($)
Cash and Cash Equivalents [Abstract]  
Amortized Cost, Due in one year or less $ 801,828
Amortized Cost, Due after one year through two years 103,009
Amortized Cost 904,837
Estimated Fair Market Value, Due in one year or less 800,827
Estimated Fair Market Value, Due after one year through two years 103,040
Total $ 903,867
v3.10.0.1
Accounts Receivable, Net - Accounts Receivable (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Receivables [Abstract]        
Accounts receivable $ 61,134 $ 51,334    
Unbilled accounts receivable 9,787 8,403    
Less: allowance for doubtful accounts (4,838) (5,341) $ (1,337) $ (3,378)
Accounts receivable, net $ 66,083 $ 54,396    
v3.10.0.1
Accounts Receivable, Net - Allowance for Doubtful Accounts (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Allowance for doubtful accounts:      
Balance, beginning of period $ 5,341 $ 1,337 $ 3,378
Additions charged to expense 869 7,349 2,681
Less: write-offs, net of recoveries and other adjustments (1,372) (3,345) (4,722)
Balance, end of period $ 4,838 $ 5,341 $ 1,337
v3.10.0.1
Inventory (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Inventory Disclosure [Abstract]    
Work-in-progress $ 45,943 $ 0
Finished goods 116,886 0
Inventory $ 162,829 $ 0
v3.10.0.1
Contract Cost Assets (Details) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenue from Contract with Customer [Abstract]      
Contract cost assets $ 45,819,000 $ 0  
Impairment of contract cost assets 0    
Amortization of contract cost assets $ 36,013,000 $ 0 $ 0
v3.10.0.1
Property and Equipment, Net - Detail of Property and Equipment (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Property, Plant and Equipment [Line Items]    
Property and equipment $ 305,927 $ 258,501
Less: accumulated amortization and depreciation (170,755) (146,230)
Property and equipment, net 135,172 112,271
Website development costs    
Property, Plant and Equipment [Line Items]    
Property and equipment 149,891 130,072
Computer equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment 22,477 30,071
Leasehold improvements    
Property, Plant and Equipment [Line Items]    
Property and equipment 65,012 47,321
Construction-in-progress    
Property, Plant and Equipment [Line Items]    
Property and equipment 29,037 28,150
Office equipment, furniture and fixtures    
Property, Plant and Equipment [Line Items]    
Property and equipment $ 39,510 $ 22,887
v3.10.0.1
Property and Equipment, Net - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Property, Plant and Equipment [Line Items]      
Amortization and depreciation expense related to property and equipment other than website development costs $ 19,500 $ 15,600 $ 13,500
Capitalization of website development costs 34,100 49,900 49,500
Amortization of website development costs and intangible assets included in technology and development 79,309 94,349 87,060
Technology and Development      
Property, Plant and Equipment [Line Items]      
Amortization of website development costs and intangible assets included in technology and development 50,800 54,300 47,000
Technology and Development | Software Development      
Property, Plant and Equipment [Line Items]      
Amortization of website development costs and intangible assets included in technology and development $ 28,600 $ 40,000 $ 40,000
v3.10.0.1
Acquisitions and Equity Investments - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
Oct. 31, 2018
Sep. 06, 2017
Jan. 11, 2017
Feb. 22, 2016
Oct. 31, 2016
Dec. 31, 2018
Dec. 31, 2017
Jun. 30, 2017
Schedule of Equity Method Investments [Line Items]                
Goodwill acquired           $ 53,831,000    
Non-cash impairment charge           79,000,000    
June 2017 Investment                
Schedule of Equity Method Investments [Line Items]                
Equity interest in privately held corporation           0.0   $ 10,000,000.0
Non-cash impairment charge           10,000,000.0    
October 2016 Investment                
Schedule of Equity Method Investments [Line Items]                
Impairment loss           0    
Upward adjustment           0    
Downward adjustment           0    
October 2016 Investment | Variable Interest Entity, Not Primary Beneficiary                
Schedule of Equity Method Investments [Line Items]                
Equity interest in privately held corporation         $ 10,000,000.0      
Percentage of equity interest in privately held variable interest entity         10.00%      
Maximum exposure to loss in variable interest entity           $ 10,000,000.0    
Mortgage Lenders of America, L.L.C.                
Schedule of Equity Method Investments [Line Items]                
Business acquisition, purchase price $ 66,700,000              
Unaudited pro forma revenue           3.00% 5.00%  
Intangible assets $ 2,600,000              
Graphic Language, Inc. - New Home Feed Business                
Schedule of Equity Method Investments [Line Items]                
Goodwill acquired   $ 3,600,000            
Identifiable intangible asset acquired   $ 1,900,000            
HREO                
Schedule of Equity Method Investments [Line Items]                
Goodwill acquired     $ 4,000,000.0          
Intangible assets     2,100,000          
Net liabilities acquired     $ 100,000          
Naked Apartments Inc                
Schedule of Equity Method Investments [Line Items]                
Intangible assets       $ 3,700,000        
Business acquisition purchase price in cash       $ 13,200,000        
v3.10.0.1
Acquisitions and Equity Investments - Purchase Price Allocation (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Oct. 31, 2018
Dec. 31, 2017
Feb. 22, 2016
Business Acquisition [Line Items]        
Goodwill $ 1,984,907   $ 1,931,076  
Mortgage Lenders of America, L.L.C.        
Business Acquisition [Line Items]        
Cash and cash equivalents   $ 10,796    
Restricted cash   753    
Mortgage loans available for sale   34,248    
Property, plant and equipment   1,315    
Intangible assets   2,600    
Goodwill   53,831    
Other acquired assets   3,079    
Accounts payable   (1,953)    
Accrued expenses   (2,591)    
Warehouse lines of credit   (32,536)    
Other assumed liabilities   (2,855)    
Total purchase price   $ 66,687    
Naked Apartments Inc        
Business Acquisition [Line Items]        
Current assets       $ 371
Intangible assets       3,700
Goodwill       10,610
Current liabilities       (101)
Deferred tax liabilities       (1,416)
Total purchase price       $ 13,164
v3.10.0.1
Goodwill - Change in Goodwill (Detail)
$ in Thousands
12 Months Ended
Dec. 31, 2018
USD ($)
Goodwill [Roll Forward]  
Balance as of December 31, 2017 $ 1,931,076
Goodwill recorded in connection with acquisition of MLOA 53,831
Balance as of December 31, 2018 $ 1,984,907
v3.10.0.1
Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]    
Cost $ 290,527 $ 287,587
Accumulated Amortization (182,623) (144,876)
Net 107,904 142,711
Purchased content    
Finite-Lived Intangible Assets [Line Items]    
Cost 42,110 35,260
Accumulated Amortization (30,477) (20,480)
Net 11,633 14,780
Software    
Finite-Lived Intangible Assets [Line Items]    
Cost 24,296 18,957
Accumulated Amortization (13,925) (8,899)
Net 10,371 10,058
Customer relationships    
Finite-Lived Intangible Assets [Line Items]    
Cost 103,900 103,900
Accumulated Amortization (60,733) (46,365)
Net 43,167 57,535
Developed technology    
Finite-Lived Intangible Assets [Line Items]    
Cost 111,980 113,380
Accumulated Amortization (72,788) (56,664)
Net 39,192 56,716
Trade names and trademarks    
Finite-Lived Intangible Assets [Line Items]    
Cost 4,900 4,900
Accumulated Amortization (4,683) (3,943)
Net 217 957
Advertising relationships    
Finite-Lived Intangible Assets [Line Items]    
Cost   9,000
Accumulated Amortization   (8,525)
Net   475
MLOA lender licenses    
Finite-Lived Intangible Assets [Line Items]    
Cost 400  
Accumulated Amortization (17)  
Net 383  
Intangibles-in-progress    
Finite-Lived Intangible Assets [Line Items]    
Cost 2,941 2,190
Accumulated Amortization 0 0
Net $ 2,941 $ 2,190
v3.10.0.1
Intangible Assets - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Oct. 01, 2017
Finite-Lived Intangible Assets [Line Items]        
Amortization of website development costs and intangible assets included in technology and development $ 79,309 $ 94,349 $ 87,060  
Non-cash impairment of indefinite-lived intangible assets 79,000 174,000 0  
Trulia        
Finite-Lived Intangible Assets [Line Items]        
Indefinite-lived intangible asset 108,000 177,000   $ 351,000
Trulia | Trade names and trademarks        
Finite-Lived Intangible Assets [Line Items]        
Non-cash impairment of indefinite-lived intangible assets 69,000 174,000    
Technology and Development        
Finite-Lived Intangible Assets [Line Items]        
Amortization of website development costs and intangible assets included in technology and development $ 50,800 $ 54,300 $ 47,000  
v3.10.0.1
Intangible Assets - Estimated Future Amortization Expense for Intangible Assets (Detail)
$ in Thousands
Dec. 31, 2018
USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]  
2019 $ 42,648
2020 39,420
2021 33,908
2022 5,480
2023 373
Total future amortization expense $ 121,829
v3.10.0.1
Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Accrued Expenses and Other Current Liabilities [Line Items]    
Total accrued expenses and other current liabilities $ 63,101 $ 61,373
Accrued marketing and advertising    
Accrued Expenses and Other Current Liabilities [Line Items]    
Total accrued expenses and other current liabilities 18,559 17,180
Accrued purchased content    
Accrued Expenses and Other Current Liabilities [Line Items]    
Total accrued expenses and other current liabilities 4,256 5,984
Accrued estimated legal liabilities and legal fees    
Accrued Expenses and Other Current Liabilities [Line Items]    
Total accrued expenses and other current liabilities 7,305 9,052
Merger consideration payable to former stockholders of certain acquired entities    
Accrued Expenses and Other Current Liabilities [Line Items]    
Total accrued expenses and other current liabilities 5,904 5,904
Other accrued expenses and other current liabilities    
Accrued Expenses and Other Current Liabilities [Line Items]    
Total accrued expenses and other current liabilities $ 27,077 $ 23,253
v3.10.0.1
Deferred Revenue (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2018
USD ($)
Change in Contract with Customer, Liability [Roll Forward]  
Balance as of January 1, 2018 $ 31,918
Deferral of revenue 982,647
Less: Revenue recognized (980,485)
Balance as of December 31, 2018 34,080
Revenue recognized, recorded in deferred revenue as of prior period $ 28,800
v3.10.0.1
Debt - Additional Information (Detail)
1 Months Ended 12 Months Ended
Jul. 31, 2018
USD ($)
Jul. 03, 2018
USD ($)
d
$ / shares
Dec. 12, 2016
USD ($)
d
$ / shares
Dec. 31, 2016
USD ($)
Jan. 31, 2015
Dec. 31, 2018
USD ($)
agreement
d
$ / shares
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Sep. 30, 2018
USD ($)
Feb. 28, 2015
USD ($)
Debt Instrument [Line Items]                    
Outstanding borrowings on revolving credit facility           $ 116,700,000 $ 0      
Net proceeds used to purchase capped call confirmations           29,414,000 0 $ 36,616,000    
Interest expense           41,255,000 27,517,000 7,408,000    
Amortization of discount and issuance costs           26,672,000 18,012,000 883,000    
Proceeds from issuance of Notes, net of issuance costs           364,020,000 0 447,784,000    
Issuance of Convertible Senior notes, transaction costs       $ 2,494,000   2,047,000   2,494,000    
Class C Capital Stock                    
Debt Instrument [Line Items]                    
Public offering price (usd per share) | $ / shares   $ 57.00                
1.50% Convertible Senior Notes Due 2023                    
Debt Instrument [Line Items]                    
Equity component of convertible debt           78,600,000        
Interest expense           10,100,000        
Amortization of discount and issuance costs           7,300,000        
Contractual coupon interest           $ 2,800,000        
Effective interest rate           6.99%        
Debt instrument amortization period           54 months        
Debt instrument carrying value           $ 294,738,000        
1.50% Convertible Senior Notes Due 2023 | Class C Capital Stock                    
Debt Instrument [Line Items]                    
Conversion price (usd per share) | $ / shares           $ 78.37        
1.50% Convertible Senior Notes Due 2023 | Fair Value, Inputs, Level 3                    
Debt Instrument [Line Items]                    
Fair value of convertible notes           $ 321,900,000        
1.50% Convertible Senior Notes Due 2023 | Convertible Debt                    
Debt Instrument [Line Items]                    
Debt instrument, interest rate stated percentage   1.50%                
Debt instrument, principal amount issued   $ 373,800,000                
Net proceeds from issuance   364,000,000.0                
Net proceeds used to purchase capped call confirmations   $ 29,400,000                
Debt instrument, conversion rate shares   0.0127592                
Conversion price (usd per share) | $ / shares   $ 78.37                
Debt instrument, convertible threshold percentage   130.00%                
Debt instrument, convertible threshold trading days | d   20                
Debt instrument, threshold consecutive trading days | d   30                
Initial cap price (usd per share) | $ / shares   $ 105.45                
Capped call confirmation premium percentage   85.00%                
1.50% Convertible Senior Notes Due 2023 | Convertible Debt | Debt Instrument, Redemption, Period One                    
Debt Instrument [Line Items]                    
Repurchase price percentage of principal amount   100.00%                
1.50% Convertible Senior Notes Due 2023 | Convertible Debt | Debt Instrument, Redemption, Period Two                    
Debt Instrument [Line Items]                    
Repurchase price percentage of principal amount   100.00%                
1.50% Convertible Senior Notes due 2023, Over-Allotment Option | Convertible Debt                    
Debt Instrument [Line Items]                    
Debt instrument, principal amount issued   $ 48,800,000                
2.00% Convertible Senior Notes Due 2021                    
Debt Instrument [Line Items]                    
Debt instrument, interest rate stated percentage     2.00%              
Debt instrument, principal amount issued     $ 460,000,000.0              
Net proceeds used to purchase capped call confirmations     $ 36,600,000              
Repurchase price percentage of principal amount     100.00%              
Interest expense           28,600,000 27,200,000 1,300,000    
Amortization of discount and issuance costs           19,400,000 18,000,000.0 900,000    
Contractual coupon interest           $ 9,200,000 $ 9,200,000 $ 500,000    
Effective interest rate       7.44%   7.44% 7.44% 7.44%    
Debt instrument amortization period           35 months        
Initial cap price (usd per share) | $ / shares           $ 69.19        
Capped call confirmation premium percentage           85.00%        
Proceeds from issuance of Notes, net of issuance costs     $ 447,800,000              
Partial repurchase of Notes       $ 370,200,000            
Equity component of issuance of 2021 Notes     91,400,000              
Issuance of Convertible Senior notes, transaction costs     12,200,000              
Amount of fees paid     $ 11,500,000              
Accrued interest           $ 800,000 $ 800,000      
Debt instrument carrying value           $ 394,645,000 375,279,000      
2.00% Convertible Senior Notes Due 2021 | Class C Capital Stock                    
Debt Instrument [Line Items]                    
Debt instrument, conversion rate shares           0.0190985        
Conversion price (usd per share) | $ / shares     $ 52.36     $ 52.36        
Debt instrument, convertible threshold percentage     130.00%              
Debt instrument, convertible threshold trading days | d     20              
Debt instrument, threshold consecutive trading days | d     30              
2.00% Convertible Senior Notes Due 2021 | Fair Value, Inputs, Level 3                    
Debt Instrument [Line Items]                    
Fair value of convertible notes           $ 446,200,000 509,000,000.0      
2.00% Convertible Senior Notes Due 2021, Over-Allotment Option                    
Debt Instrument [Line Items]                    
Debt instrument, principal amount issued     $ 60,000,000.0              
2.75% Convertible Senior Notes Due 2020                    
Debt Instrument [Line Items]                    
Debt instrument, interest rate stated percentage           2.75%        
Debt instrument, conversion rate shares         0.0278303          
Repurchase price percentage of principal amount           100.00%        
Interest expense           $ 300,000 300,000 $ 6,100,000    
Debt repurchase aggregate principal amount       $ 219,900,000       $ 219,900,000    
Debt instrument carrying value           $ 9,600,000 10,100,000     $ 230,000,000.0
2.75% Convertible Senior Notes Due 2020 | Class A Common Stock                    
Debt Instrument [Line Items]                    
Debt instrument, convertible threshold percentage           130.00%        
Debt instrument, convertible threshold trading days | d           20        
Debt instrument, threshold consecutive trading days | d           30        
2.75% Convertible Senior Notes Due 2020 | Class C Common Stock Distribution | Class A Common Stock                    
Debt Instrument [Line Items]                    
Debt instrument, conversion rate shares           0.0414550        
Conversion price (usd per share) | $ / shares           $ 24.12        
2.75% Convertible Senior Notes Due 2020 | Fair Value, Inputs, Level 3                    
Debt Instrument [Line Items]                    
Fair value of convertible notes           $ 16,700,000 $ 17,600,000      
Mortgage Lenders of America, L.L.C.                    
Debt Instrument [Line Items]                    
Number of warehouse lines of credit | agreement           2        
Trulia Merger Agreement | 2.75% Convertible Senior Notes Due 2020 | Class A Common Stock                    
Debt Instrument [Line Items]                    
Debt instrument, conversion rate shares           0.0123567        
Conversion price (usd per share) | $ / shares           $ 80.93        
Common stock exchange ratio           0.444        
Revolving Credit Facility                    
Debt Instrument [Line Items]                    
Maximum borrowing capacity           $ 500,000,000.0        
Current borrowing capacity                 $ 126,700,000  
Revolving credit facility, initial term 1 year                  
Revolving credit facility, extension of initial term 2 years                  
Availability limit, acquisition cost of residential property 85.00%                  
Availability limit, market value of residential property 85.00%                  
Amount available for future borrowings           $ 383,300,000        
Weighted average interest rate           5.86%        
Revolving Credit Facility | Credit Suisse AG, Cayman Islands Branch                    
Debt Instrument [Line Items]                    
Maximum borrowing capacity $ 250,000,000.0         $ 500,000,000.0        
Line of Credit | Warehouse Lines of Credit, due July 2019                    
Debt Instrument [Line Items]                    
Maximum borrowing capacity           50,000,000.0        
Line of Credit | Mortgage Lenders of America, L.L.C. | Warehouse Lines of Credit, due March 2019                    
Debt Instrument [Line Items]                    
Maximum borrowing capacity           $ 50,000,000.0        
Weighted average interest rate           4.88%        
Line of Credit | Mortgage Lenders of America, L.L.C. | Warehouse Lines of Credit, due July 2019                    
Debt Instrument [Line Items]                    
Weighted average interest rate           4.73%        
Line of Credit | Mortgage Lenders of America, L.L.C. | Warehouse Lines of Credit                    
Debt Instrument [Line Items]                    
Maximum borrowing capacity           $ 100,000,000.0        
v3.10.0.1
Debt - Outstanding Principal Amount and Carrying Value (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
1.50% Convertible Senior Notes Due 2023    
Debt Instrument [Line Items]    
Outstanding Principal Amount $ 373,750  
Unamortized Debt Discount and Debt Issuance Costs (79,012)  
Carrying Value 294,738  
2.00% Convertible Senior Notes Due 2021    
Debt Instrument [Line Items]    
Outstanding Principal Amount 460,000 $ 460,000
Unamortized Debt Discount and Debt Issuance Costs (65,355) (84,721)
Carrying Value $ 394,645 $ 375,279
v3.10.0.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Feb. 28, 2015
Schedule Of Income Tax [Line Items]          
Income tax (benefit) expense $ 31,102 $ 89,586 $ (130)    
Effective tax rate 20.70% 48.70% (0.10%)    
Adjustment to income tax (benefit) under the Tax Act $ (5,900)        
Non-cash impairment of indefinite-lived intangible assets 79,000 $ 174,000 $ 0    
Income tax benefit, Tax Cuts and Jobs Act, reduction in net deferred tax liability   23,600      
Increase/decrease in valuation allowance 32,800 57,500      
Unrecognized tax benefits 28,625 21,613 $ 15,395 $ 13,980  
Unrecognized income tax accrued interest and penalties 0        
Research and Development          
Schedule Of Income Tax [Line Items]          
Net operating loss carryforwards $ 48,800 35,800      
Tax credit carryforwards expiration year 2025        
Trulia          
Schedule Of Income Tax [Line Items]          
Income tax (benefit) expense $ 15,400 66,000      
Trade names and trademarks | Trulia          
Schedule Of Income Tax [Line Items]          
Non-cash impairment of indefinite-lived intangible assets 69,000 174,000      
Indefinite-lived intangible asset         $ 351,000
Federal          
Schedule Of Income Tax [Line Items]          
Net operating loss carryforwards 1,081,700 1,014,000      
State          
Schedule Of Income Tax [Line Items]          
Net operating loss carryforwards $ 32,500 $ 21,400      
v3.10.0.1
Income Taxes - Components of Income Tax (Benefit) Expense (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Current income tax expense      
Foreign $ 161 $ 0 $ 0
Total current income tax expense 161 0 0
Deferred income tax (benefit) expense      
Federal (28,502) (84,238) (1,248)
State (2,441) (5,348) 1,378
Foreign (320) 0 0
Total deferred income tax (benefit) expense (31,263) (89,586) 130
Total income tax (benefit) expense $ (31,102) $ (89,586) $ 130
v3.10.0.1
Income Taxes - Reconciliation of Federal Statutory Rate and Effective Tax Rate (Detail)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Abstract]      
Tax expense at federal statutory rate (21.00%) (35.00%) (35.00%)
State income taxes, net of federal tax benefit (5.90%) (4.40%) (1.90%)
Nondeductible expenses 0.00% 0.80% 4.90%
Share-based compensation (16.50%) (20.60%) (0.20%)
IRC section 162(m) 1.00% 0.00% 0.00%
Research and development credits (8.40%) (6.30%) (1.50%)
Meals and entertainment 1.80% 0.00% 0.00%
Return to provision adjustments (4.20%) 0.00% 0.00%
Enactment of Tax Act (1.90%) (13.10%) 0.00%
Other 0.40% 2.20% (0.90%)
Valuation allowance 34.00% 27.70% 34.70%
Effective tax rate (20.70%) (48.70%) 0.10%
v3.10.0.1
Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Deferred tax assets:    
Federal and state net operating loss carryforwards $ 259,629 $ 234,316
Share-based compensation 55,280 47,655
Start-up and organizational costs 99 146
Research and development credits 48,805 35,793
Other tax credits 910 910
Accruals and reserves 3,000 2,729
Deferred rent 4,842 5,484
Other deferred tax assets 14,267 8,342
Total deferred tax assets 386,832 335,375
Deferred tax liabilities:    
Website and software development costs (14,685) (13,202)
Goodwill (598) (688)
Intangible assets (45,035) (69,241)
Discount on 2021 Notes and 2023 Notes not deductible for tax (31,450) (19,374)
Depreciation and amortization (888) (2,425)
Total deferred tax liabilities (92,656) (104,930)
Net deferred tax assets before valuation allowance 294,176 230,445
Less: valuation allowance (307,599) (274,810)
Net deferred tax liabilities $ (13,423) $ (44,365)
v3.10.0.1
Income Taxes - Changes in Unrecognized Tax Benefits (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]      
Unrecognized tax benefits beginning balance $ 21,613 $ 15,395 $ 13,980
Gross increases - prior and current period tax positions     2,619
Gross decreases - prior period tax positions     (1,204)
Gross increases - current period tax positions 6,421 5,216  
Gross increases - prior period tax positions 591 1,002  
Unrecognized tax benefits ending balance $ 28,625 $ 21,613 $ 15,395
v3.10.0.1
Shareholders' Equity - Additional Information (Detail)
$ / shares in Units, $ in Millions
12 Months Ended
Jul. 03, 2018
USD ($)
$ / shares
shares
Dec. 31, 2018
Vote
shares
Dec. 31, 2017
shares
Dec. 31, 2016
shares
Class of Stock [Line Items]        
Preferred stock, shares issued (in shares)   0 0  
Preferred stock, shares outstanding (in shares)   0 0  
Class A Common Stock        
Class of Stock [Line Items]        
Common stock holders voting right | Vote   1    
Conversion of common stock conversion ratio   1    
Number of common stock issued   0 0 0
Class B Common Stock        
Class of Stock [Line Items]        
Common stock holders voting right | Vote   10    
Number of common stock converted   0 0 0
Class C Capital Stock        
Class of Stock [Line Items]        
Common stock holders voting right | Vote   0    
Public offering price (usd per share) | $ / shares $ 57.00      
Net proceeds from public offering | $ $ 360.3      
Public Stock Offering | Class C Capital Stock        
Class of Stock [Line Items]        
Shares issued and sold (in shares) 6,557,017      
Over-Allotment Option | Class C Capital Stock        
Class of Stock [Line Items]        
Shares issued and sold (in shares) 855,263      
v3.10.0.1
Shareholders' Equity - Common and Capital Stock Reserved for Future Issuance (Detail) - shares
Dec. 31, 2018
Dec. 31, 2017
Class of Stock [Line Items]    
Options and Stock Appreciation Rights Outstanding (in shares)   26,645,206
Total (in shares) 42,468,963 41,955,956
Class B Common Stock    
Class of Stock [Line Items]    
Shares issuable upon conversion of outstanding Class B common stock (in shares) 6,217,447 6,217,447
Option Awards    
Class of Stock [Line Items]    
Options and Stock Appreciation Rights Outstanding (in shares) 27,310,110  
Option awards outstanding (in shares)   26,645,206
Option Awards | 2011 Plan    
Class of Stock [Line Items]    
Class A common stock and Class C capital stock available for grant under 2011 Plan (in shares) 3,675,082 5,076,898
Restricted Stock Units    
Class of Stock [Line Items]    
Unvested amount (in shares) 5,266,324 4,016,405
Restricted stock units outstanding (in shares)   4,016,405
v3.10.0.1
Share-Based Awards - Zillow Group, Inc. Incentive Plan - Additional Information (Detail) - shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Common stock reserved for future issuance (in shares) 42,468,963 41,955,956
Amended and Restated 2011 Incentive Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Common stock reserved for future issuance (in shares) 18,400,000  
Increase in number of shares of common and capital stock available for issuance percentage 3.50%  
Increase in number of shares of common and capital stock available for issuance 10,500,000  
2011 Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Exercise price per share fixed 100.00%  
2011 Plan | Option Awards    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share based compensation arrangement by share based payment, award minimum exercisable period 3 months  
Share based compensation arrangement by share based payment, award maximum exercisable period 12 months  
2011 Plan | Option Awards | Vesting After 12 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting percentage 25.00%  
Vesting period 12 months  
2011 Plan | Option Awards | Vesting After 36 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 36 months  
2011 Plan | Option Awards | Quarterly Vesting Over 4 Years    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 4 years  
2011 Plan | Option Awards | Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expiration period 7 years  
2011 Plan | Option Awards | Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expiration period 10 years  
2011 Plan | Restricted Stock Units    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting percentage 25.00%  
2011 Plan | Restricted Stock Units | Vesting After 12 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 4 years  
2011 Plan | Restricted Stock Units | Vesting After 36 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting percentage 12.50%  
2011 Plan | Restricted Stock Units | Minimum | Vesting After 12 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 12 months  
2011 Plan | Restricted Stock Units | Minimum | Vesting After 36 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 6 months  
2011 Plan | Restricted Stock Units | Maximum | Vesting After 12 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 3 years  
2011 Plan | Restricted Stock Units | Maximum | Vesting After 36 Months    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vesting period 3 years 6 months  
v3.10.0.1
Share-Based Awards - Trulia Stock Incentive Plan - Additional Information (Detail)
12 Months Ended
Dec. 31, 2018
Trulia 2012 Equity Incentive Plan  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expiration period 10 years
Exercise price per share fixed 100.00%
Trulia 2005 Stock Incentive Plan  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expiration period 10 years
Trulia 2005 Stock Incentive Plan | Minimum  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting period 12 months
Trulia 2005 Stock Incentive Plan | Maximum  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting period 36 months
Trulia 2005 Stock Incentive Plan | Vesting After 12 Months  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting percentage 25.00%
Trulia 2005 Stock Incentive Plan | Monthly Vesting Over Two to Four Years | Minimum | Option Awards  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting period 2 years
Trulia 2005 Stock Incentive Plan | Monthly Vesting Over Two to Four Years | Maximum | Option Awards  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting period 4 years
v3.10.0.1
Share-Based Awards - Summary of Option Award and Stock Appreciation Rights Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Number of Shares Subject to Existing Options    
Number of Shares Subject to Existing Option Awards and Stock Appreciation Rights, Beginning Balance (in shares) 26,645,206  
Number of Shares Subject to Existing Option Awards and Stock Appreciation Rights, Granted (in shares) 6,963,320  
Number of Shares Subject to Existing Option Awards and Stock Appreciation Rights, Exercised (in shares) (5,472,728)  
Number of Shares Subject to Existing Option Awards and Stock Appreciation Rights, Forfeited or cancelled (in shares) (825,688)  
Number of Shares Subject to Existing Option Awards and Stock Appreciation Rights, Ending Balance (in shares)   26,645,206
Number of Shares Subject to Existing Option Awards and Stock Appreciation Rights, Vested and exercisable, Ending balance (in shares) 15,287,932  
Weighted- Average Exercise Price Per Share    
Weighted-Average Exercise Price Per Share, Beginning Balance (usd per share) $ 27.70  
Weighted-Average Exercise Price Per Share, Granted (usd per share) 48.95  
Weighted-Average Exercise Price Per Share, Exercised (usd per share) 21.94  
Weighted-Average Exercise Price Per Share, Forfeited or cancelled (usd per share) 35.32  
Weighted-Average Exercise Price Per Share, Ending Balance (usd per share) 34.04 $ 27.70
Weighted-Average Exercise Price Per Share, Vested and exercisable (usd per share) $ 29.73  
Weighted- Average Remaining Contractual Life (Years)    
Weighted-Average Remaining Contractual Life (Years) 6 years 2 months 23 days 5 years 8 months 19 days
Weighted-Average Remaining Contractual Life (Years), Vested and exercisable 4 years 8 months 19 days  
Aggregate Intrinsic Value (in thousands)    
Aggregate Intrinsic Value $ 97,941 $ 355,739
Aggregate Intrinsic Value Vested, and exercisable $ 75,867  
v3.10.0.1
Share-Based Awards - Fair Value of Options Granted, Excluding Options Grant to Executives Estimated at Date of Grant Using Black Scholes Merton Option Pricing Model (Detail) - Option Awards - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected volatility, minimum 42.00% 45.00% 49.00%
Expected volatility, maximum 45.00% 49.00% 51.00%
Expected dividend yield 0.00% 0.00% 0.00%
Risk-free interest rate, minimum 2.52% 1.67% 0.89%
Risk-free interest rate, maximum 2.84% 2.06% 1.89%
Weighted-average fair value of options granted (usd per share) $ 19.11 $ 14.51 $ 9.42
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average expected life 4 years 6 months 4 years 3 months 3 years 9 months
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted-average expected life 5 years 4 years 9 months 4 years 3 months
v3.10.0.1
Share-Based Awards - Option Awards and Stock Appreciation Rights - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation arrangement by share-based payment award, option awards, exercises in period, total intrinsic value $ 161.4 $ 156.1 $ 51.7
Stock Option and Stock Appreciation Rights      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized cost of unvested share-based compensation awards $ 176.7    
Unrecognized compensation cost expected recognition period 2 years 8 months 12 days    
Option Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Fair value of options $ 87.7 84.8 87.9
Stock Appreciation Rights (SARs)      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total fair value of awards vested $ 87.7 $ 84.8 $ 87.9
v3.10.0.1
Share-Based Awards - Summary of Restricted Stock Units Activity (Detail) - Restricted Stock Units
12 Months Ended
Dec. 31, 2018
$ / shares
shares
Restricted Stock Units  
Unvested outstanding, beginning balance (in shares) | shares 4,016,405
Granted (in shares) | shares 3,725,726
Vested (in shares) | shares (1,740,134)
Forfeited or cancelled (in shares) | shares (735,673)
Unvested outstanding, ending balance (in shares) | shares 5,266,324
Weighted-Average Grant-Date Fair Value  
Unvested outstanding, beginning balance (usd per share) | $ / shares $ 33.22
Granted (usd per share) | $ / shares 48.26
Vested (usd per share) | $ / shares 35.63
Forfeited or cancelled (usd per share) | $ / shares 39.59
Unvested outstanding, ending balance (usd per share) | $ / shares $ 42.19
v3.10.0.1
Share-Based Awards - Restricted Stock Units - Additional Information (Detail) - Restricted Stock Units - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total fair value of restricted stock vested $ 62.0 $ 43.7 $ 46.5
Total unrecognized compensation cost $ 204.9    
Unrecognized compensation cost expected recognition period 2 years 10 months 24 days    
v3.10.0.1
Share-Based Awards - Effects of Share Based Compensation in Consolidated Statements of Operations (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation $ 149,084 $ 113,571 $ 106,918
Cost of Revenue      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation 4,127 3,884 3,550
Sales and Marketing      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation 22,942 22,735 23,320
Technology and Development      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation 56,673 39,938 31,466
General and Administrative      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation $ 65,342 $ 47,014 $ 48,582
v3.10.0.1
Net Loss Per Share - Additional Information (Detail) - $ / shares
shares in Millions
12 Months Ended
Dec. 31, 2018
Dec. 12, 2016
2.00% Convertible Senior Notes Due 2021    
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]    
Conversion spread, shares 8.8  
2.00% Convertible Senior Notes Due 2021 | Class C Capital Stock    
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]    
Conversion price (usd per share) $ 52.36 $ 52.36
1.50% Convertible Senior Notes Due 2023    
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]    
Conversion spread, shares 4.8  
1.50% Convertible Senior Notes Due 2023 | Class C Capital Stock    
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]    
Conversion price (usd per share) $ 78.37  
v3.10.0.1
Net Loss Per Share - Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares
shares in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Class A Common Stock and Class C Capital Stock      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total Class A common stock and Class C capital stock equivalents (in shares) 28,085 32,695 24,040
Class A Common Stock and Class C Capital Stock | Option Awards | Weighted Average      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total Class A common stock and Class C capital stock equivalents (in shares) 22,736 27,998 19,993
Class A Common Stock and Class C Capital Stock | Restricted Stock Awards and Restricted Stock Units | Weighted Average      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total Class A common stock and Class C capital stock equivalents (in shares) 4,949 4,262 3,607
Class A Common Stock | 2.75% Convertible Senior Notes Due 2020      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total Class A common stock and Class C capital stock equivalents (in shares) 400 435 440
v3.10.0.1
Commitments and Contingencies - Future Minimum Payments for All Operating Leases (Detail)
$ in Thousands
Dec. 31, 2018
USD ($)
Commitments and Contingencies Disclosure [Abstract]  
2019 $ 29,085
2020 38,060
2021 40,099
2022 37,721
2023 36,458
All future years 85,462
Total future minimum lease payments $ 266,885
v3.10.0.1
Commitments and Contingencies - Additional Information (Detail)
12 Months Ended
Jun. 20, 2017
USD ($)
Feb. 09, 2017
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Feb. 28, 2018
claim
Sep. 30, 2017
claim
Other Commitments [Line Items]              
Rent expense     $ 23,700,000 $ 21,400,000 $ 16,600,000    
Non-cancelable purchase commitments     160,866,000        
Outstanding surety bonds     8,900,000 3,700,000      
VHT Vs Zillow Group Inc              
Other Commitments [Line Items]              
Jury awarded damages $ 4,100,000 $ 79,875          
Estimated immaterial liability in general and administrative expenses     $ 4,100,000 $ 4,100,000      
VHT Vs Zillow Group Inc | Statutory Damages              
Other Commitments [Line Items]              
Jury awarded damages   $ 8,200,000          
Class Action Lawsuits              
Other Commitments [Line Items]              
Number of pending claims | claim             2
Shareholder Derivative Lawsuits              
Other Commitments [Line Items]              
Number of pending claims | claim           4  
v3.10.0.1
Commitments and Contingencies - Purchase Commitments for Content Related to Mobile Applications and Websites (Detail)
$ in Thousands
Dec. 31, 2018
USD ($)
Purchase Obligations  
2019 $ 64,124
2020 64,007
2021 32,735
Total future purchase commitments 160,866
Homes Under Contract  
Purchase Obligations  
2019 88,943
2020 0
2021 0
Total future purchase commitments $ 88,943
v3.10.0.1
Related Party Transactions - Additional Information (Detail) - USD ($)
$ in Millions
1 Months Ended
Apr. 30, 2016
Feb. 29, 2016
Mr.Lloyd Frink    
Related Party Transaction [Line Items]    
Reimbursement of costs incurred   $ 0.2
Mr.Richard Barton    
Related Party Transaction [Line Items]    
Reimbursement of costs incurred $ 0.1 $ 0.2
v3.10.0.1
Self-Insurance - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Insurance [Line Items]    
Minimum amount of individual claim under self insurance plan $ 150,000  
Liability for self-insured claims included in accrued compensation and benefits $ 3,900,000 $ 2,000,000.0
Minimum    
Insurance [Line Items]    
Percentage of cumulative medical claim under self insurance plan 125.00%  
Maximum    
Insurance [Line Items]    
Cumulative medical claim under self-insurance plan amount $ 1,000,000.0  
v3.10.0.1
Employee Benefit Plan - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Defined Contribution Plan Disclosure [Line Items]      
Company's expense related to its defined contribution 401(k) retirement plans $ 16.0 $ 12.3 $ 10.1
Maximum | Zillow Merger      
Defined Contribution Plan Disclosure [Line Items]      
Company's contribution based on employee contribution 4.00%    
v3.10.0.1
Segment Information and Revenue - Additional Information (Detail) - segment
9 Months Ended 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Segment Reporting [Abstract]      
Number of operating segments 2   1
Number of reportable segments 2 1  
v3.10.0.1
Segment Information and Revenue - Revenue Categories (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenue:      
Total revenue $ 1,333,554 $ 1,076,794 $ 846,589
Costs and Expenses [Abstract]      
Cost of revenue 153,590    
Sales and marketing 552,621 448,201 382,419
Technology and development 410,818 319,985 255,583
General and administrative 262,153 210,816 332,007
Impairment costs 79,000    
Acquisition-related costs 2,332 463 1,423
Integration costs 2,015 0 0
Total costs and expenses 1,462,529 1,238,668 1,039,443
Loss from operations (128,975) (161,874) (192,854)
Other income 19,270 5,385 2,711
Interest expense (41,255) (27,517) (7,408)
Loss before income taxes (150,960) $ (184,006) $ (220,308)
Premier Agent      
Revenue:      
Total revenue 898,332    
Rentals      
Revenue:      
Total revenue 134,587    
Mortgages      
Revenue:      
Total revenue 80,046    
Other      
Revenue:      
Total revenue 168,224    
Homes      
Revenue:      
Total revenue 52,365    
IMT      
Revenue:      
Total revenue 1,281,189    
Costs and Expenses [Abstract]      
Cost of revenue 104,330    
Sales and marketing 534,038    
Technology and development 389,539    
General and administrative 238,727    
Impairment costs 79,000    
Acquisition-related costs 2,332    
Integration costs 2,015    
Total costs and expenses 1,349,981    
Loss from operations (68,792)    
Other income 19,270    
Interest expense (39,078)    
Loss before income taxes (88,600)    
IMT | Premier Agent      
Revenue:      
Total revenue 898,332    
IMT | Rentals      
Revenue:      
Total revenue 134,587    
IMT | Mortgages      
Revenue:      
Total revenue 80,046    
IMT | Other      
Revenue:      
Total revenue 168,224    
IMT | Homes      
Revenue:      
Total revenue 0    
Homes      
Revenue:      
Total revenue 52,365    
Costs and Expenses [Abstract]      
Cost of revenue 49,260    
Sales and marketing 18,583    
Technology and development 21,279    
General and administrative 23,426    
Impairment costs 0    
Acquisition-related costs 0    
Integration costs 0    
Total costs and expenses 112,548    
Loss from operations (60,183)    
Other income 0    
Interest expense (2,177)    
Loss before income taxes (62,360)    
Homes | Premier Agent      
Revenue:      
Total revenue 0    
Homes | Rentals      
Revenue:      
Total revenue 0    
Homes | Mortgages      
Revenue:      
Total revenue 0    
Homes | Other      
Revenue:      
Total revenue 0    
Homes | Homes      
Revenue:      
Total revenue $ 52,365    
v3.10.0.1
Subsequent Events - Additional Information (Details) - Revolving Credit Facility - USD ($)
Jan. 31, 2019
Dec. 31, 2018
Subsequent Event [Line Items]    
Maximum borrowing capacity   $ 500,000,000.0
Subsequent Event | Credit Agreement | Citibank, N.A.    
Subsequent Event [Line Items]    
Maximum borrowing capacity $ 500,000,000.0  
Initial borrowing capacity $ 50,000,000.0  
Initial credit agreement term 2 years  
Option to extend, term 1 year  
v3.10.0.1
Label Element Value
Cumulative Effect of New Accounting Principle in Period of Adoption us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption $ 40,322,000
Cumulative Effect of New Accounting Principle in Period of Adoption us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption 0
Additional Paid-in Capital [Member]  
Cumulative Effect of New Accounting Principle in Period of Adoption us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption 780,000
Retained Earnings [Member]  
Cumulative Effect of New Accounting Principle in Period of Adoption us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption 40,322,000
Cumulative Effect of New Accounting Principle in Period of Adoption us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption $ (780,000)