Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2019	Jul. 19, 2019
Document and Entity Information Abstract
Title of 12(b) Security	Common stock, no par value
Entity Incorporation, State or Country Code	IL
Entity Registrant Name	MORNINGSTAR, INC.
Entity Central Index Key	0001289419
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	000-51280
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		42,763,022
Entity Tax Identification Number	36-3297908
Entity Address, Address Line One	22 West Washington Street
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60602
Trading Symbol	MORN
Security Exchange Name	NASDAQ
City Area Code	312
Local Phone Number	696-6000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false

Unaudited Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenue	$ 273.9	$ 252.4	$ 532.8	$ 495.9
Operating expense:
Cost of revenue	107.5	99.8	212.6	202.2
Sales and marketing	45.7	39.4	85.7	77.9
General and administrative	44.0	36.0	84.8	68.2
Depreciation and amortization	25.9	23.6	49.4	46.5
Total operating expense	223.1	198.8	432.5	394.8
Operating income	50.8	53.6	100.3	101.1
Non-operating income (expense), net:
Interest income (expense), net	0.7	(0.7)	0.0	(1.0)
Gain (loss) on sale of investments, reclassified from other comprehensive income	(0.2)	0.1	0.4	0.6
Gain on sale of product line	0.0	0.0	0.0	10.5
Other income (expense), net	1.8	2.0	(1.4)	0.6
Non-operating income (expense), net	2.3	1.4	(1.0)	10.7
Income before income taxes and equity in net loss of unconsolidated entities	53.1	55.0	99.3	111.8
Equity in net income (loss) of unconsolidated entities	0.7	(0.4)	(0.8)	(1.9)
Income tax expense	11.7	12.8	23.2	26.2
Consolidated net income	$ 42.1	$ 41.8	$ 75.3	$ 83.7
Net income per share:
Basic (in dollars per share)	$ 0.99	$ 0.98	$ 1.77	$ 1.97
Diluted (in dollars per share)	0.98	0.97	1.75	1.95
Dividends declared (in dollars per share)	0.28	0.25	0.56	0.50
Dividends paid per common share (in dollars per share)	$ 0.28	$ 0.25	$ 0.56	$ 0.50
Weighted average shares outstanding:
Basic (in shares)	42.7	42.6	42.7	42.6
Diluted (in shares)	43.1	43.0	43.1	43.0

Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Consolidated net income	$ 42.1	$ 41.8	$ 75.3	$ 83.7
Other comprehensive income (loss):
Foreign currency translation adjustment	(2.8)	(21.6)	0.6	(14.1)
Unrealized gains (losses) on securities, net of tax:
Unrealized holding gains (losses) arising during the period	0.3	0.3	2.2	0.3
Reclassification (gains) losses included in net income	0.2	(0.1)	(0.3)	(0.5)
Other comprehensive income (loss)	(2.3)	(21.4)	2.5	(14.3)
Comprehensive income	$ 39.8	$ 20.4	$ 77.8	$ 69.4

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

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+ Details

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 383.8	$ 369.3
Investments	30.1	26.6
Accounts receivable, less allowance of $2.9 and $4.0, respectively	169.2	172.2
Income tax receivable	1.1	1.8
Deferred commissions	13.5	14.8
Other current assets	22.2	16.9
Total current assets	619.9	601.6
Goodwill	556.5	556.7
Property, equipment, and capitalized software, less accumulated depreciation and amortization of $383.3 and $351.7, respectively	140.4	143.5
Operating lease assets	111.8	0.0
Intangible assets, net	64.7	73.9
Investments in unconsolidated entities	61.4	63.1
Deferred commissions, non-current	12.5	10.3
Other assets	5.1	4.7
Total assets	1,572.3	1,453.8
Current liabilities:
Deferred revenue	232.9	195.8
Accrued compensation	72.0	109.5
Accounts payable and accrued liabilities	45.3	54.4
Operating lease liabilities	29.6	0.0
Other current liabilities	1.6	3.1
Total current liabilities	381.4	362.8
Operating lease liabilities, non-current	109.4	0.0
Accrued compensation	12.5	11.8
Deferred tax liability, net	21.1	22.2
Long-term debt	15.0	70.0
Deferred revenue, non-current	14.4	14.2
Other long-term liabilities	15.1	38.1
Total liabilities	568.9	519.1
Morningstar, Inc. shareholders’ equity:
Common stock, no par value, 200,000,000 shares authorized, of which 42,763,022 and 42,624,118 shares were outstanding as of June 30, 2019 and December 31, 2018, respectively	0.0	0.0
Treasury stock at cost, 10,851,109 and 10,816,672 shares as of June 30, 2019 and December 31, 2018, respectively	(730.4)	(726.8)
Additional paid-in capital	640.1	621.7
Retained earnings	1,166.2	1,114.8
Accumulated other comprehensive loss:
Currency translation adjustment	(73.9)	(74.5)
Unrealized gain (loss) on available-for-sale investments	1.4	(0.5)
Total accumulated other comprehensive loss	(72.5)	(75.0)
Total equity	1,003.4	934.7
Total liabilities and equity	$ 1,572.3	$ 1,453.8

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 2.9	$ 4.0
Accumulated depreciation and amortization	$ 383.3	$ 351.7
Common Stock, No Par Value	$ 0	$ 0
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares, Outstanding	42,763,022	42,624,118
Treasury Stock, Shares	10,851,109	10,816,672

Unaudited Condensed Consolidated Statement of Equity - USD ($) $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2017	$ 804.9	$ 0.0	$ (708.2)	$ 601.0	$ 958.7	$ (46.6)
Balance (in shares) at Dec. 31, 2017		42,547,707
Increase (Decrease) in Stockholders' Equity
Net income	41.9				41.9
Other comprehensive income:
Reclassification of adjustments for gain included in net income, net of income tax	(0.4)					(0.4)
Foreign currency translation adjustment	7.5					7.5
Other comprehensive income	7.1					7.1
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units (in shares)		79,050
Issuance of common stock related to option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units	(4.1)			(4.1)
Reclassification of awards previously liability-classified that were converted to equity	4.4			4.4
Stock-based compensation	6.6			6.6
Common share repurchased (in shares)		(92,529)
Common shares repurchased	(8.9)		(8.9)
Dividends declared	(10.6)				(10.6)
Balance at Mar. 31, 2018	858.3	$ 0.0	(717.1)	607.9	1,007.0	(39.5)
Balance (in shares) at Mar. 31, 2018		42,534,228
Balance at Dec. 31, 2017	804.9	$ 0.0	(708.2)	601.0	958.7	(46.6)
Balance (in shares) at Dec. 31, 2017		42,547,707
Increase (Decrease) in Stockholders' Equity
Net income	83.7
Other comprehensive income:
Unrealized gain on available-for-sale investments, net of income tax	0.3
Reclassification of adjustments for gain included in net income, net of income tax	(0.5)
Foreign currency translation adjustment	(14.1)
Other comprehensive income	(14.3)
Balance at Jun. 30, 2018	871.4	$ 0.0	(717.5)	611.7	1,038.1	(60.9)
Balance (in shares) at Jun. 30, 2018		42,636,066
Balance at Mar. 31, 2018	858.3	$ 0.0	(717.1)	607.9	1,007.0	(39.5)
Balance (in shares) at Mar. 31, 2018		42,534,228
Increase (Decrease) in Stockholders' Equity
Net income	41.8				41.8
Other comprehensive income:
Unrealized gain on available-for-sale investments, net of income tax	0.3					0.3
Reclassification of adjustments for gain included in net income, net of income tax	(0.1)					(0.1)
Foreign currency translation adjustment	(21.6)					(21.6)
Other comprehensive income	(21.4)					(21.4)
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units (in shares)		118,598
Issuance of common stock related to option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units	(5.2)		1.2	(6.4)
Reclassification of awards previously liability-classified that were converted to equity	0.2			0.2
Stock-based compensation	10.0			10.0
Common share repurchased (in shares)		(16,760)
Common shares repurchased	(1.6)		(1.6)
Dividends declared	(10.7)				(10.7)
Balance at Jun. 30, 2018	871.4	$ 0.0	(717.5)	611.7	1,038.1	(60.9)
Balance (in shares) at Jun. 30, 2018		42,636,066
Balance at Dec. 31, 2018	$ 934.7	$ 0.0	(726.8)	621.7	1,114.8	(75.0)
Balance (in shares) at Dec. 31, 2018	42,624,118	42,624,118
Increase (Decrease) in Stockholders' Equity
Net income	$ 33.2				33.2
Other comprehensive income:
Unrealized gain on available-for-sale investments, net of income tax	1.9					1.9
Reclassification of adjustments for gain included in net income, net of income tax	(0.5)					(0.5)
Foreign currency translation adjustment	3.4					3.4
Other comprehensive income	4.8					4.8
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units (in shares)		73,530
Issuance of common stock related to option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units	(4.6)	$ 0.0	0.0	(4.6)
Reclassification of awards previously liability-classified that were converted to equity	6.6	$ 0.0	0.0	6.6	0.0	0.0
Stock-based compensation	10.0			10.0
Common share repurchased (in shares)		(41,935)
Common shares repurchased	(4.6)	$ 0.0	(4.6)	0.0	0.0	0.0
Dividends declared	(11.9)				(11.9)
Balance at Mar. 31, 2019	968.2	$ 0.0	(731.4)	633.7	1,136.1	(70.2)
Balance (in shares) at Mar. 31, 2019		42,655,713
Balance at Dec. 31, 2018	$ 934.7	$ 0.0	(726.8)	621.7	1,114.8	(75.0)
Balance (in shares) at Dec. 31, 2018	42,624,118	42,624,118
Increase (Decrease) in Stockholders' Equity
Net income	$ 75.3
Other comprehensive income:
Unrealized gain on available-for-sale investments, net of income tax	2.2
Reclassification of adjustments for gain included in net income, net of income tax	(0.3)
Foreign currency translation adjustment	0.6
Other comprehensive income	2.5
Balance at Jun. 30, 2019	$ 1,003.4	$ 0.0	(730.4)	640.1	1,166.2	(72.5)
Balance (in shares) at Jun. 30, 2019	42,763,022	42,763,022
Balance at Mar. 31, 2019	$ 968.2	$ 0.0	(731.4)	633.7	1,136.1	(70.2)
Balance (in shares) at Mar. 31, 2019		42,655,713
Increase (Decrease) in Stockholders' Equity
Net income	42.1				42.1
Other comprehensive income:
Unrealized gain on available-for-sale investments, net of income tax	0.3					0.3
Reclassification of adjustments for gain included in net income, net of income tax	0.2					0.2
Foreign currency translation adjustment	(2.8)					(2.8)
Other comprehensive income	(2.3)					(2.3)
Issuance of common stock related to stock-option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units (in shares)		107,309
Issuance of common stock related to option exercises and vesting of restricted stock units, net of shares withheld for taxes on settlements of restricted stock units	(5.3)	$ 0.0	1.0	(6.3)
Reclassification of awards previously liability-classified that were converted to equity	0.2	$ 0.0	0.0	0.2	0.0	0.0
Stock-based compensation	12.5			12.5
Common share repurchased (in shares)		0
Common shares repurchased	0.0	$ 0.0	0.0	0.0	0.0	0.0
Dividends declared	(12.0)				(12.0)
Balance at Jun. 30, 2019	$ 1,003.4	$ 0.0	$ (730.4)	$ 640.1	$ 1,166.2	$ (72.5)
Balance (in shares) at Jun. 30, 2019	42,763,022	42,763,022

Condensed Consolidated Statement of Equity (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Taxes from unrealized gain on available-for-sale investments	$ 0.1	$ 0.7	$ 0.3
Reclassification of adjustments for gains included in net income, net of income tax of	$ 0.1	$ 0.2	$ 0.1	$ 0.1
Dividends declared (in dollars per share)	$ 0.28	$ 0.28	$ 0.25	$ 0.25

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Consolidated net income	$ 75.3	$ 83.7
Adjustments to reconcile consolidated net income to net cash flows from operating activities:
Depreciation and amortization	49.4	46.5
Deferred income taxes	(1.8)	5.6
Stock-based compensation expense	22.5	16.6
Provision for bad debt	0.5	1.1
Equity in net loss of unconsolidated entities	0.8	1.9
Gain on sale of product line	0.0	(10.5)
Other, net	0.7	(1.0)
Changes in operating assets and liabilities:
Accounts receivable	2.5	(18.1)
Deferred commissions	0.9	22.9
Accounts payable and accrued liabilities	(4.5)	(0.9)
Accrued compensation	(31.7)	(45.8)
Income taxes, current	1.6	(11.8)
Deferred revenue	37.2	38.8
Other assets and liabilities	(7.2)	0.7
Cash provided by operating activities	146.2	129.7
Investing activities
Purchases of investments	(19.1)	(16.5)
Proceeds from maturities and sales of investments	19.7	15.7
Capital expenditures	(37.0)	(35.6)
Proceeds from sale of a product line	0.0	10.5
Purchases of equity investments	(1.2)	(0.2)
Other, net	(0.4)	0.1
Cash used for investing activities	(38.0)	(26.0)
Financing activities
Common shares repurchased	(4.9)	(10.8)
Dividends paid	(23.9)	(21.3)
Repayment of long-term debt	(55.0)	(55.0)
Employee taxes paid from withholding of restricted stock units	(9.9)	(9.3)
Other, net	(0.5)	(0.6)
Cash used for financing activities	(94.2)	(97.0)
Effect of exchange rate changes on cash and cash equivalents	0.5	(7.8)
Net increase (decrease) in cash and cash equivalents	14.5	(1.1)
Cash and cash equivalents—beginning of period	369.3	308.2
Cash and cash equivalents—end of period	383.8	307.1
Supplemental disclosure of cash flow information:
Cash paid for income taxes	23.3	38.0
Cash paid for interest	1.2	1.9
Supplemental information of non-cash investing and financing activities:
Unrealized gain (loss) on available-for-sale investments	$ 2.6	$ (0.6)

Basis of Presentation of Interim Financial Information	6 Months Ended
Basis of Presentation of Interim Financial Information	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation of Interim Financial Information	Basis of Presentation of Interim Financial Information The accompanying unaudited condensed consolidated financial statements of Morningstar, Inc. and subsidiaries (Morningstar, we, our, the Company) have been prepared to conform to the rules and regulations of the Securities and Exchange Commission (SEC). The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amount of assets, liabilities, revenue, and expenses. Actual results could differ from those estimates. In the opinion of management, the statements reflect all adjustments, which are of a normal recurring nature, necessary to present fairly our financial position, results of operations, equity, and cash flows. These financial statements and notes are unaudited and should be read in conjunction with our Audited Consolidated Financial Statements and Notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2018, filed with the SEC on March 1, 2019 (our Annual Report). The acronyms that appear in the Notes to our Unaudited Condensed Consolidated Financial Statements refer to the following: ASC: Accounting Standards Codification ASU: Accounting Standards Update FASB: Financial Accounting Standards Board

Summary of Significant Accounting Policies	6 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Significant changes to our accounting policies as a result of adopting ASU No. 2016-02, Leases, are discussed below. We discuss our other significant accounting policies in Note 2 of our Audited Consolidated Financial Statements included in our Annual Report. Recently adopted accounting pronouncements Leases: On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which requires lessees to recognize almost all leases on their balance sheet as a right-of-use asset and a lease liability. Expenses are recognized in the consolidated statement of income in a manner similar to previous accounting guidance. Topic 842 originally required the use of a modified retrospective approach upon adoption. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842) - Targeted Improvements, which allows an additional transition method to adopt the new lease standard at the adoption date instead of the beginning of the earliest period presented. We elected this transition method at the adoption date of January 1, 2019. We also chose to elect the following practical expedients upon adoption: not to reassess whether any expired or existing contracts are or contain leases, not to reassess the lease classification for any expired or existing leases, not to reassess initial direct costs for any existing leases, and not to separately identify lease and nonlease components (i.e. maintenance costs) except for real estate leases. Additionally, we elected the short-term lease exemption, and are only applying the requirements of Topic 842 to long-term leases (leases greater than 1 year). The adoption of Topic 842 resulted in the presentation of $118.8 million of operating lease assets and $145.8 million of operating lease liabilities on the consolidated balance sheet as of March 31, 2019. At implementation, we also reclassified $27.9 million in deferred rent liabilities related to these leases, which decreased recognized operating lease assets. The new standard did not have a material impact on the statement of income. See Note 9 for additional information. Income Statement-Reporting Comprehensive Income: On February 14, 2018, the FASB issued ASU No. 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, to address a specific consequence of the Tax Cuts and Jobs Act of 2017 (the Tax Reform Act) by allowing a reclassification from accumulated other comprehensive income (loss) to retained earnings for stranded tax effects resulting from the Tax Reform Act’s reduction of the U.S. federal corporate income tax rate. The new standard became effective for us on January 1, 2019 and is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Reform Act is recognized. We did not elect to reclassify any stranded tax effects from accumulated other comprehensive income (loss) to retained earnings, therefore, the adoption did not have an impact on our consolidated financial statements and related disclosures. Compensation—Stock Compensation: On June 20, 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718) - Improvements to Nonemployee Share-Based Payment Accounting, which aligns the accounting for share-based payment awards issued to employees and nonemployees. Under the new standard, the existing employee guidance will apply to nonemployee share-based transactions (as long as the transaction is not effectively a form of financing), with the exception of specific guidance related to the attribution of compensation cost. The cost of nonemployee awards will continue to be recorded as if the grantor had paid cash for the goods or services. In addition, the contractual term can be used in lieu of an expected term in the option-pricing model for nonemployee awards. The new standard became effective for us on January 1, 2019 and will be applied to all new awards granted after the date of adoption. The adoption did not have an impact on our consolidated financial statements and related disclosures. Codification Improvements to Investments - Debt and Equity Securities: On July 17, 2018, the FASB issued ASU No. 2018-09, Codification Improvements, which modifies the disclosure requirements on debt and equity securities related to ASC 320, Investments - Debt and Equity Securities. ASU No. 2018-09 removes the requirement for these disclosures when an entity provides summarized interim financial information. The new standard became effective for us on January 1, 2019. The adoption did not have an impact on our consolidated financial statements. Recently issued accounting pronouncements not yet adopted Current Expected Credit Losses: On June 16, 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires that expected credit losses relating to financial assets measured on an amortized cost basis and available-for-sale debt securities be recorded through an allowance for credit losses. ASU No. 2016-13 limits the amount of credit losses to be recognized for available-for-sale debt securities to the amount by which carrying value exceeds fair value and also requires the reversal of previously recognized credit losses if fair value increases. The new standard is effective for us on January 1, 2020. Early adoption is permitted. On April 25, 2019, the FASB issued ASU No. 2019-04, Codification Improvements, which clarifies certain aspects of accounting for credit losses. On May 15, 2019, the FASB issued ASU No. 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief, which allows entities to elect the fair value option on certain financial instruments.We are currently evaluating the impact of adopting ASU No. 2016-13, ASU No. 2019-04 and ASU No. 2019-05 on our consolidated financial statements and related disclosures. Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement: On August 28, 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates, adds and modifies certain disclosure requirements around items such as transfers between Level 1 and 2, policy of timing of transfers, and valuation process for Level 3. The new standard is effective for us on January 1, 2020. We are currently evaluating the impact of adopting ASU No. 2018-13 on our consolidated financial statements and related disclosures. Cloud Computing: On August 29, 2018, the FASB issued ASU No. 2018-15, Customer's Accounting for Fees Paid in a Cloud Computing Arrangement, which helps entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (CCA) by providing guidance for determining when an arrangement includes a software license and when an arrangement is solely a hosted CCA service. Under ASU No. 2018-15, customers will apply the same criteria for capitalizing implementation costs as they would for an arrangement that has a software license. The new guidance also prescribes the balance sheet, income statement, and cash flow classification of the capitalized implementation costs and related amortization expense and requires additional quantitative and qualitative disclosures. The new standard is effective for us on January 1, 2020. Early adoption is permitted, including adoption in any interim period for which financial statements have not been issued. Entities can choose to adopt the new guidance prospectively to eligible costs incurred on or after the date this guidance is first applied or retrospectively. We are currently evaluating the impact of adopting ASU No. 2018-15 on our consolidated financial statements and related disclosures.

Credit Arrangements	6 Months Ended
Credit Arrangements	Jun. 30, 2019
Debt Disclosure [Abstract]
Credit Arrangements	Credit Arrangements In December 2018, we amended our credit agreement to extend the maturity date to December 21, 2020 with no other changes in terms. The credit agreement provides us with a borrowing capacity of up to $300.0 million and provides for issuance of up to $25.0 million of letters of credit. The interest rate applicable to any loan under the credit agreement is, at our option, either: (i) the applicable London interbank offered rate (LIBOR) plus an applicable margin for such loans, which ranges between 1.00% and 1.75%, based on our consolidated leverage ratio or (ii) the lender's base rate plus the applicable margin for such loans, which ranges between 2.00% and 2.75%, based on our consolidated leverage ratio. The credit agreement also contains financial covenants under which we: (i) may not exceed a maximum consolidated leverage ratio of 3.00 to 1.00 and (ii) are required to maintain a minimum consolidated interest coverage ratio of not less than 3.00 to 1.00. We were in compliance with the financial covenants as of June 30, 2019. Our outstanding principal balance was $15.0 million at a one-month LIBOR interest rate plus 100 basis points as of June 30, 2019, leaving borrowing availability of $285.0 million. See Note 14 for information regarding our new senior credit agreement effective as of July 2, 2019.

Goodwill and Other Intangible Assets

6 Months Ended

Jun. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Other Intangible Assets

Acquisitions, Divestitures, Goodwill, and Other Intangible Assets

Acquisitions

We did not complete any significant acquisitions in the second quarter of 2019.

See Note 14 for information regarding subsequent acquisition activity.

Divestitures

During the second quarter of 2019, we signed an agreement to divest our equity interest in one of our investments in unconsolidated entities. The transaction is expected to close during the third quarter of 2019.

Goodwill

The following table shows the changes in our goodwill balances from December 31, 2018 to June 30, 2019:



	(in millions)
Balance as of December 31, 2018	$	556.7
Foreign currency translation	(0.2		)
Balance as of June 30, 2019	$	556.5

We did not record any impairment losses in the first six months of 2019 and 2018. We perform our annual impairment reviews in the fourth quarter and when triggering events are identified.

Intangible Assets

The following table summarizes our intangible assets:



	As of June 30, 2019								As of December 31, 2018
(in millions)	Gross		Accumulated Amortization			Net		Weighted Average Useful Life (years)	Gross		Accumulated Amortization			Net		Weighted Average Useful Life (years)
Intellectual property	$	30.8	$	(29.6	)	$	1.2	9	$	30.8	$	(29.2	)	$	1.6	9
Customer-related assets	154.0		(115.3		)	38.7		12	153.0		(111.7		)	41.3		12
Supplier relationships	0.2		(0.1		)	0.1		20	0.2		(0.1		)	0.1		20
Technology-based assets	126.9		(102.5		)	24.4		7	126.9		(96.3		)	30.6		7
Non-competition agreements	2.4		(2.1		)	0.3		5	2.4		(2.1		)	0.3		5
Total intangible assets	$	314.3	$	(249.6	)	$	64.7	10	$	313.3	$	(239.4	)	$	73.9	10

The following table summarizes our amortization expense related to intangible assets:



	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
Amortization expense	$	4.9	$	5.2	$	9.8	$	10.5

We amortize intangible assets using the straight-line method over their expected economic useful lives.

We expect intangible amortization expense for the remainder of 2019 and subsequent years as follows:



	(in millions)
Remainder of 2019 (from July 1 through December 31)	$	9.4
2020	16.2
2021	12.8
2022	5.0
2023	5.0
Thereafter	16.3

Our estimates of future amortization expense for intangible assets may be affected by acquisitions, divestitures, changes in the estimated average useful lives, and foreign currency translation.

Income Per Share

6 Months Ended

Jun. 30, 2019

Earnings Per Share [Abstract]

Income Per Share

The following table shows how we reconcile our net income and the number of shares used in computing basic and diluted net income per share:



	Three months ended June 30,				Six months ended June 30,
(in millions, except per share amounts)	2019		2018		2019		2018
Basic net income per share:
Consolidated net income	$	42.1	$	41.8	$	75.3	$	83.7

Weighted average common shares outstanding	42.7		42.6		42.7		42.6

Basic net income per share	$	0.99	$	0.98	$	1.77	$	1.97

Diluted net income per share:
Consolidated net income	$	42.1	$	41.8	$	75.3	$	83.7

Weighted average common shares outstanding	42.7		42.6		42.7		42.6
Net effect of dilutive stock options, restricted stock units, performance share awards, and market stock units	0.4		0.4		0.4		0.4
Weighted average common shares outstanding for computing diluted income per share	43.1		43.0		43.1		43.0

Diluted net income per share	$	0.98	$	0.97	$	1.75	$	1.95

The number of weighted average restricted stock units, performance share awards, and market stock units excluded from our calculation of diluted earnings per share, as their inclusion would have been anti-dilutive, was immaterial during the periods presented.

Revenue

6 Months Ended

Jun. 30, 2019

Revenue from Contract with Customer [Abstract]

Revenue

Disaggregation of Revenue

The following table presents our revenue disaggregated by revenue type. Sales and usage-based taxes are excluded from revenue.



	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
License-based	$	200.9	$	184.3	$	396.4	$	362.9
Asset-based	52.6		48.7		101.5		99.4
Transaction-based	20.4		19.4		34.9		33.6
Consolidated revenue	$	273.9	$	252.4	$	532.8	$	495.9

License-based performance obligations are generally satisfied over time as the customer has access to the product or service during the term of the subscription license and the level of service is consistent during the contract period. License-based agreements typically have a term of 12 to 36 months. License-based revenue is sourced from Morningstar Data, Morningstar Direct, Morningstar Advisor Workstation, Morningstar Enterprise Components, Morningstar Research, PitchBook, and other similar products.

Asset-based performance obligations are satisfied over time as the customer receives continuous access to a service for the term of the contract or contract period. Asset-based arrangements typically have a term of 12 to 36 months. Asset-based fees represent variable consideration and the customer does not make separate purchasing decisions that result in additional performance obligations. Significant changes in the underlying fund assets, or significant disruptions in the market, are evaluated to determine if revisions of estimates of earned asset-based fees are needed for the current quarter. An estimate of variable consideration is included in the initial transaction price only to the extent it is probable that a significant reversal in the amount of the revenue recognized will not occur. Estimates of asset-based fees are based on the most recently completed quarter and, as a result, it is unlikely a significant reversal of revenue would occur. Asset-based revenue includes Morningstar Investment Management, Workplace Solutions, and Morningstar Indexes. For the Morningstar Funds Trust, revenue from advisory fees and expenses for sub-advisory fees are recognized on a gross basis in accordance with the applicable revenue recognition guidance.

Transaction-based performance obligations are satisfied when the product or service is completed or delivered. Transaction-based revenue includes Morningstar Credit Ratings, Internet Advertising Sales, and Conferences. Morningstar Credit Ratings may include surveillance services, which are recognized over time, as the customer has access to the service during the surveillance period.

Contract liabilities

Our contract liabilities represent deferred revenue. We record contract liabilities when cash payments are received or due in advance of our performance, including amounts which are refundable. The contract liabilities balance as of June 30, 2019 had a net increase of $37.3 million, primarily driven by cash payments received or due in advance of satisfying our performance obligations. We recognized $156.2 million of revenue in the six-month period ended June 30, 2019 that was included in the contract liabilities balance as of December 31, 2018.

We expect to recognize revenue related to our contract liabilities for the remainder of 2019 and subsequent years as follows:



(in millions)	As of June 30, 2019
Remainder of 2019 (from July 1 through December 31)	$	278.7
2020	184.4
2021	50.9
2022	15.3
2023	7.0
Thereafter	50.4
	$	586.7

The aggregate amount of revenue we expect to recognize for the remainder of 2019 and subsequent years is higher than our contract liability balance of $247.3 million as of June 30, 2019. The difference represents the value of future obligations for signed contracts where we have not yet begun to satisfy the performance obligations or have partially satisfied performance obligations.

The table above does not include variable consideration for unsatisfied performance obligations related to certain of our asset-based and transaction-based contracts as of June 30, 2019. We are applying the optional exemption as the variable consideration relates to these unsatisfied performance obligations being fulfilled as a series. The performance obligations related to these contracts are expected to be satisfied over the next 12 to 36 months as services are provided to the client. For license-based contracts, the consideration received for services performed is based on future user count, which will be known at the time the services are performed. The variable consideration for this revenue can be affected by the number of user licenses. For asset-based contracts, the consideration received for services performed is based on future asset values, which will be known at the time the services are performed. The variable consideration for this revenue can be affected by changes in the underlying value of fund assets due to client redemptions, additional investments, or significant movements in the market. For transaction-based contracts such as Internet advertising, the consideration received for services performed is based on the number of impressions, which will be known once impressions are created. The variable consideration for this revenue can be affected by the timing and quantity of impressions in any given period.

The table above does not include revenue for unsatisfied performance obligations related to certain of our license-based and transaction-based contracts as of June 30, 2019. We are applying the optional exemption as the performance obligations for such contracts have an expected duration of one year or less. For certain license-based contracts, the remaining performance obligation is expected to be less than one year based on the corresponding subscription terms. For transaction-based contracts, such as new credit rating issuances and the Morningstar conference, the related performance obligations are expected to be satisfied within the next 12 months.

Contract Assets

Our contract assets represent accounts receivable, less allowance and deferred commissions. We did not record any impairment losses on receivables or deferred commissions in the first six months of 2019.

The following table summarizes our contract assets balance:



(in millions)	As of June 30, 2019		As of December 31, 2018
Accounts receivable, less allowance	$	169.2	$	172.2
Deferred commissions	13.5		14.8
Deferred commissions, non-current	12.5		10.3
Total contract assets	$	195.2	$	197.3

The following table shows the change in our deferred commissions balance from December 31, 2018 to June 30, 2019:



	(in millions)
Balance as of December 31, 2018	$	25.1
Commissions earned and capitalized	10.5
Amortization of capitalized amounts	(9.6		)
Balance as of June 30, 2019	$	26.0

Segment and Geographical Area Information

6 Months Ended

Jun. 30, 2019

Segment Reporting [Abstract]

Segment and Geographical Area Information

Segment Information

We report our results in a single reportable segment, which reflects how our chief operating decision maker allocates resources and evaluates our financial results. Because we have a single reportable segment, all required financial segment information can be found directly in the Consolidated Financial Statements. The accounting policies for our reportable segment are the same as those described in “Note 2. Summary of Significant Accounting Policies” included in the Audited Consolidated Financial Statements and Notes thereto included in our Annual Report. We evaluate the performance of our reporting segment based on revenue and operating income.

Geographical Area Information

The tables below summarize our revenue and long-lived assets, which includes property, equipment, and capitalized software, net and operating lease assets, by geographical area:



Revenue by geographical area
	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
United States	$	208.0	$	187.8	$	403.1	$	367.3

United Kingdom	18.8		18.4		36.9		36.7
Continental Europe	20.9		20.3		41.3		40.2
Australia	10.0		10.8		19.5		21.3
Canada	7.8		7.5		15.7		15.2
Asia	6.8		6.1		13.1		12.2
Other	1.6		1.5		3.2		3.0
Total International	65.9		64.6		129.7		128.6

Consolidated revenue	$	273.9	$	252.4	$	532.8	$	495.9



Property, equipment, and capitalized software, net by geographical area

(in millions)	As of June 30, 2019		As of December 31, 2018
United States	$	122.9	$	126.4

United Kingdom	3.5		3.8
Continental Europe	1.2		1.3
Australia	4.6		5.0
Canada	0.3		0.3
Asia	7.3		6.5
Other	0.6		0.2
Total International	17.5		17.1

Consolidated property, equipment, and capitalized software, net	$	140.4	$	143.5



Operating lease assets by geographical area

(in millions)	As of June 30, 2019		As of December 31, 2018
United States	$	65.9	$	—

United Kingdom	6.1		—
Continental Europe	4.9		—
Australia	6.1		—
Canada	2.7		—
Asia	25.2		—
Other	0.9		—
Total International	45.9		—

Consolidated operating lease assets	$	111.8	$	—

As of December 31, 2018, there were no operating lease assets as Topic 842 became effective for the Company on January 1, 2019.

The long-lived asset by geographical area does not include deferred commissions, non-current as the balance is not significant.

Investments and Fair Value Measurements	6 Months Ended
Investments and Fair Value Measurements	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Investments and Fair Value Measurements	Fair Value Measurements As of June 30, 2019 and December 31, 2018, our investment balances totaled $30.1 million and $26.6 million, respectively. We classify our investments into three categories: available-for-sale, held-to-maturity, and trading securities. Our investment portfolio consists of stocks, bonds, options, mutual funds, money market funds, or exchange-traded products that replicate the model portfolios and strategies created by Morningstar. These investment accounts may also include exchange-traded products where Morningstar is an index provider. All investments in our investment portfolio have valuations based on quoted prices in active markets for identical assets or liabilities that we have the ability to access, and, therefore, are classified as Level 1 within the fair value hierarchy.

Leases

6 Months Ended

Jun. 30, 2019

Leases [Abstract]

Leases

We lease office space and certain equipment under various operating and finance leases, with the majority of our lease portfolio consisting of operating leases for office space.

We determine whether an arrangement is or includes an embedded lease at contract inception. Operating lease assets and lease liabilities are recognized at commencement date and initially measured using the present value of lease payments over the defined lease term. Lease expense is recognized on a straight-line basis over the lease term. For finance leases, we also recognize a finance lease asset and finance lease liability at inception, with lease expense recognized as interest expense and amortization.

A contract is or contains an embedded lease if the contract meets all of the below criteria:


•	There is an identified asset.


•	We obtain substantially all of the economic benefits of the asset.


•	We have the right to direct the use of the asset.

For initial measurement of the present value of lease payments and for subsequent measurement of lease modifications, we are required to use the rate implicit in the lease. However, most of our leases do not provide an implicit rate; therefore, we use our incremental borrowing rate, which is a collateralized rate. To apply the incremental borrowing rate, we used a portfolio approach and grouped leases based on similar lease terms in a manner whereby we reasonably expect that the application does not differ materially from a lease-by-lease approach.

Our leases have remaining lease terms of approximately 1 year to 10 years, which may include the option to extend the lease when it is reasonably certain we will exercise that option. We do not have lease agreements with residual value guarantees, sale leaseback terms, or material restrictive covenants.

Leases with an initial term of 12 months or less are not recognized on the balance sheet. We recognize lease expense for these leases on a straight-line basis over the lease term.

The following table summarizes our operating assets and lease liabilities:



Leases (in millions)	Balance Sheet Classification	As of June 30, 2019
Assets
Operating	Operating lease assets	$	111.8

Liabilities
Current
Operating	Operating lease liabilities	$	29.6
Non-current
Operating	Operating lease liabilities, non-current	109.4
Total lease liabilities		$	139.0

Our operating lease expense for the three and six months ended June 30, 2019 was $7.9 million and $15.8 million, respectively. Charges related to our operating leases that are variable and, therefore, not included in the measurement of the lease liabilities, were $3.1 million and $5.7 million for the three and six months ended June 30, 2019, respectively. We made lease payments of $8.2 million and $14.4 million during the three and six months ended June 30, 2019, respectively.

The following table shows our minimum future lease commitments due in each of the next five years and thereafter for operating leases:



Minimum Future Lease Commitments (in millions)	Operating Leases
Remainder of 2019 (July 1 through December 31)	$	17.2
2020	35.2
2021	31.2
2022	19.2
2023	15.3
Thereafter	38.8
Total lease payments	156.9
Adjustment for discount to present value	17.9
Total	$	139.0

As of June 30, 2019, we had $24.0 million of executed operating leases included in the table above, primarily for office space, that have not yet commenced. These leases will commence over the remainder of 2019 and 2020 with lease terms of 6 months to 10 years.

The following table summarizes the weighted-average lease terms and weighted-average discount rates for our operating leases:



	As of June 30, 2019
Weighted-average remaining lease term (in years)	5.71

Weighted-average discount rate	3.98	%

Stock-Based Compensation

6 Months Ended

Jun. 30, 2019

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation

Stock-Based Compensation Plans

All of our employees and our non-employee directors are eligible for awards under the Morningstar 2011 Stock Incentive Plan, which provides for a variety of stock-based awards, including stock options, restricted stock units, performance share awards, market stock units, and restricted stock.

The following table summarizes the stock-based compensation expense included in each of our operating expense categories:



	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
Cost of revenue	$	3.7	$	3.2	$	6.8	$	5.9
Sales and marketing	1.4		0.9		2.9		1.7
General and administrative	7.4		5.9		12.8		9.0
Total stock-based compensation expense	$	12.5	$	10.0	$	22.5	$	16.6

As of June 30, 2019, the total unrecognized stock-based compensation cost related to outstanding restricted stock units, performance share awards, and market stock units expected to vest was $59.1 million, which we expect to recognize over a weighted average period of 29 months.

Income Taxes

6 Months Ended

Jun. 30, 2019

Income Tax Disclosure [Abstract]

Income Taxes

Effective Tax Rate

The following table shows our effective tax rate for the three and six months ended June 30, 2019 and June 30, 2018:



	Three months ended June 30,						Six months ended June 30,
(in millions)	2019			2018			2019			2018
Income before income taxes and equity in net income (loss) of unconsolidated entities	$	53.1		$	55.0		$	99.3		$	111.8
Equity in net income (loss) of unconsolidated entities	0.7			(0.4		)	(0.8		)	(1.9		)
Total	$	53.8		$	54.6		$	98.5		$	109.9
Income tax expense	$	11.7		$	12.8		$	23.2		$	26.2
Effective tax rate	21.7		%	23.4		%	23.6		%	23.8		%

Our effective tax rate in the second quarter and first six months of 2019 was 21.7% and 23.6%, reflecting respective decreases of 1.7 and 0.2 percentage points compared with the same periods in the prior year. The decreases were primarily attributable to current year tax benefits from favorable provisions of the Tax Reform Act.

Unrecognized Tax Benefits

The table below provides information regarding our gross unrecognized tax benefits as of June 30, 2019 and December 31, 2018, as well as the effect these gross unrecognized tax benefits would have on our income tax expense, if they were recognized.



(in millions)	As of June 30, 2019		As of December 31, 2018
Gross unrecognized tax benefits	$	13.7	$	13.1
Gross unrecognized tax benefits that would affect income tax expense	13.7		13.1
Decrease in income tax expense upon recognition of gross unrecognized tax benefits	13.3		12.6

Our Unaudited Condensed Consolidated Balance Sheets include the following liabilities for unrecognized tax benefits. These amounts include interest and penalties, less any associated tax benefits.



Liabilities for Unrecognized Tax Benefits (in millions)	As of June 30, 2019		As of December 31, 2018
Current liability	$	6.6	$	6.6
Non-current liability	8.0		7.1
Total liability for unrecognized tax benefits	$	14.6	$	13.7

Because we conduct business globally, we file income tax returns in U.S. federal, state, local, and foreign jurisdictions. We are currently under audit by federal and various state and local tax authorities in the United States, as well as tax authorities in certain non-U.S. jurisdictions. It is possible that the examination phase of some of our current audits will conclude in 2019. It is not possible to reasonably estimate the effect of current audits on previously recorded unrecognized tax benefits.

Approximately 56% of our cash, cash equivalents, and investments balance as of June 30, 2019 was held by our operations outside of the United States. In February 2019, we repatriated approximately $45.8 million of our foreign earnings back to the U.S. Otherwise, we generally consider our U.S. directly-owned foreign subsidiary earnings to be permanently reinvested. We believe that our cash balances and investments in the United States, along with cash generated from our U.S. operations, will be sufficient to meet our U.S. operating and cash needs for the foreseeable future, without requiring additional repatriation of earnings from these foreign subsidiaries.

Certain of our non-U.S. operations have incurred net operating losses (NOLs), which may become deductible to the extent these operations become profitable. For each of our operations, we evaluate whether it is more likely than not that the tax benefits related to NOLs will be realized. As part of this evaluation, we consider evidence such as tax planning strategies, historical operating results, forecasted taxable income, and recent financial performance. In the year that certain non-U.S. operations record a loss, we do not recognize a corresponding tax benefit, which would result in an increase to our effective tax rate. Upon determining that it is more likely than not that the NOLs will be realized, we reduce the tax valuation allowances related to these NOLs, which results in a reduction to our income tax expense and our effective tax rate in the period.

Contingencies	6 Months Ended
Contingencies	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies We record accrued liabilities for litigation, regulatory, and other business matters when those matters represent loss contingencies that are both probable and estimable. In these cases, there may be an exposure to loss in excess of any amounts accrued. When a loss contingency is not both probable and estimable, we do not establish an accrued liability. As litigation, regulatory, or other business matter develop, we evaluate on an ongoing basis whether any such matter presents a loss contingency that is probable and estimable. Data Audits and Reviews In our global data business, we include in our products or directly redistribute to our customers data and information licensed from third-party vendors. Our compliance with the terms of these licenses is subject to audit by the third-party vendors, and we also regularly review our compliance with the terms of the licenses. We are undergoing several such third-party vendor audits and internal reviews, and the results and findings may indicate that we may be required to make a payment for prior data usage. Due to a variety of factors, including lack of available information and data, the unique nature of each audit and internal review, as well as potential variations of the audit or internal review findings, we are not able to reasonably estimate a possible loss, or range of losses, for some matters. While we cannot predict the outcomes, we do not believe the results of any audits will have a material adverse effect on our business, operating results, or financial position. Other Matters We are involved from time to time in legal proceedings and litigation that arise in the normal course of our business. While it is difficult to predict the outcome of any particular proceeding, we do not believe it to be reasonably possible for the result of any of these matters to have a material adverse effect on our business, operating results, or financial position.

Share Repurchase Program	6 Months Ended
Share Repurchase Program	Jun. 30, 2019
Equity [Abstract]
Share Repurchase Program	Share Repurchase Program In December 2017, the board of directors approved a share repurchase program that authorizes the Company to repurchase up to $500.0 million in shares of the Company's outstanding common stock effective January 1, 2018. The authorization expires on December 31, 2020. We may repurchase shares from time to time at prevailing market prices on the open market or in private transactions in amounts that we deem appropriate. As of June 30, 2019, we had repurchased a total of 244,180 shares for $25.6 million under this authorization, leaving approximately $474.4 million available for future repurchases.

Subsequent Events (Notes)	6 Months Ended
Subsequent Events (Notes)	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On July 2, 2019, we completed our previously announced acquisition of Ratings Acquisition Corp (DBRS), the world’s fourth largest credit ratings agency, for a purchase price of $669.0 million. The acquisition was financed through a combination of cash on hand and borrowings under our new senior credit agreement (the Credit Agreement) with Bank of America, N.A., as Administrative Agent, L/C Issuer and Swingline Lender. The Credit Agreement provides us with a five year multi-currency credit facility with a borrowing capacity of up to $750.0 million, including a $300.0 million revolving credit facility (the Revolving Credit Facility) and a term loan facility of $450.0 million (the Term Facility). The Credit Agreement also provides for the issuance of up to $50.0 million of letters of credit and a $100.0 million sublimit for a swingline facility under the Revolving Credit Facility. As of July 2, 2019, the aggregate principal balance outstanding under the Credit Agreement was $610.0 million. The proceeds of the Term Facility have been used solely to finance our acquisition of DBRS. The proceeds of our initial borrowing under the Revolving Credit Facility have also been used to finance such acquisition and the proceeds of future borrowings may be used for working capital, capital expenditures, and any other lawful corporate purpose. In connection with entering into the Credit Agreement, we repaid all outstanding obligations under our existing Amended and Restated Credit Agreement, dated as of November 4, 2016, as amended.

Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2019
Accounting Policies [Abstract]
Recent Accounting Pronouncements Policy	Recently adopted accounting pronouncements Leases: On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which requires lessees to recognize almost all leases on their balance sheet as a right-of-use asset and a lease liability. Expenses are recognized in the consolidated statement of income in a manner similar to previous accounting guidance. Topic 842 originally required the use of a modified retrospective approach upon adoption. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842) - Targeted Improvements, which allows an additional transition method to adopt the new lease standard at the adoption date instead of the beginning of the earliest period presented. We elected this transition method at the adoption date of January 1, 2019. We also chose to elect the following practical expedients upon adoption: not to reassess whether any expired or existing contracts are or contain leases, not to reassess the lease classification for any expired or existing leases, not to reassess initial direct costs for any existing leases, and not to separately identify lease and nonlease components (i.e. maintenance costs) except for real estate leases. Additionally, we elected the short-term lease exemption, and are only applying the requirements of Topic 842 to long-term leases (leases greater than 1 year). The adoption of Topic 842 resulted in the presentation of $118.8 million of operating lease assets and $145.8 million of operating lease liabilities on the consolidated balance sheet as of March 31, 2019. At implementation, we also reclassified $27.9 million in deferred rent liabilities related to these leases, which decreased recognized operating lease assets. The new standard did not have a material impact on the statement of income. See Note 9 for additional information. Income Statement-Reporting Comprehensive Income: On February 14, 2018, the FASB issued ASU No. 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, to address a specific consequence of the Tax Cuts and Jobs Act of 2017 (the Tax Reform Act) by allowing a reclassification from accumulated other comprehensive income (loss) to retained earnings for stranded tax effects resulting from the Tax Reform Act’s reduction of the U.S. federal corporate income tax rate. The new standard became effective for us on January 1, 2019 and is to be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Reform Act is recognized. We did not elect to reclassify any stranded tax effects from accumulated other comprehensive income (loss) to retained earnings, therefore, the adoption did not have an impact on our consolidated financial statements and related disclosures. Compensation—Stock Compensation: On June 20, 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718) - Improvements to Nonemployee Share-Based Payment Accounting, which aligns the accounting for share-based payment awards issued to employees and nonemployees. Under the new standard, the existing employee guidance will apply to nonemployee share-based transactions (as long as the transaction is not effectively a form of financing), with the exception of specific guidance related to the attribution of compensation cost. The cost of nonemployee awards will continue to be recorded as if the grantor had paid cash for the goods or services. In addition, the contractual term can be used in lieu of an expected term in the option-pricing model for nonemployee awards. The new standard became effective for us on January 1, 2019 and will be applied to all new awards granted after the date of adoption. The adoption did not have an impact on our consolidated financial statements and related disclosures. Codification Improvements to Investments - Debt and Equity Securities: On July 17, 2018, the FASB issued ASU No. 2018-09, Codification Improvements, which modifies the disclosure requirements on debt and equity securities related to ASC 320, Investments - Debt and Equity Securities. ASU No. 2018-09 removes the requirement for these disclosures when an entity provides summarized interim financial information. The new standard became effective for us on January 1, 2019. The adoption did not have an impact on our consolidated financial statements. Recently issued accounting pronouncements not yet adopted Current Expected Credit Losses: On June 16, 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which requires that expected credit losses relating to financial assets measured on an amortized cost basis and available-for-sale debt securities be recorded through an allowance for credit losses. ASU No. 2016-13 limits the amount of credit losses to be recognized for available-for-sale debt securities to the amount by which carrying value exceeds fair value and also requires the reversal of previously recognized credit losses if fair value increases. The new standard is effective for us on January 1, 2020. Early adoption is permitted. On April 25, 2019, the FASB issued ASU No. 2019-04, Codification Improvements, which clarifies certain aspects of accounting for credit losses. On May 15, 2019, the FASB issued ASU No. 2019-05, Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief, which allows entities to elect the fair value option on certain financial instruments.We are currently evaluating the impact of adopting ASU No. 2016-13, ASU No. 2019-04 and ASU No. 2019-05 on our consolidated financial statements and related disclosures. Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement: On August 28, 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates, adds and modifies certain disclosure requirements around items such as transfers between Level 1 and 2, policy of timing of transfers, and valuation process for Level 3. The new standard is effective for us on January 1, 2020. We are currently evaluating the impact of adopting ASU No. 2018-13 on our consolidated financial statements and related disclosures. Cloud Computing: On August 29, 2018, the FASB issued ASU No. 2018-15, Customer's Accounting for Fees Paid in a Cloud Computing Arrangement, which helps entities evaluate the accounting for fees paid by a customer in a cloud computing arrangement (CCA) by providing guidance for determining when an arrangement includes a software license and when an arrangement is solely a hosted CCA service. Under ASU No. 2018-15, customers will apply the same criteria for capitalizing implementation costs as they would for an arrangement that has a software license. The new guidance also prescribes the balance sheet, income statement, and cash flow classification of the capitalized implementation costs and related amortization expense and requires additional quantitative and qualitative disclosures. The new standard is effective for us on January 1, 2020. Early adoption is permitted, including adoption in any interim period for which financial statements have not been issued. Entities can choose to adopt the new guidance prospectively to eligible costs incurred on or after the date this guidance is first applied or retrospectively. We are currently evaluating the impact of adopting ASU No. 2018-15 on our consolidated financial statements and related disclosures.
Segment Reporting Policy	We report our results in a single reportable segment, which reflects how our chief operating decision maker allocates resources and evaluates our financial results. Because we have a single reportable segment, all required financial segment information can be found directly in the Consolidated Financial Statements. The accounting policies for our reportable segment are the same as those described in “Note 2. Summary of Significant Accounting Policies” included in the Audited Consolidated Financial Statements and Notes thereto included in our Annual Report. We evaluate the performance of our reporting segment based on revenue and operating income.
Investments- Debt and Equity Securities Policy	We classify our investments into three categories: available-for-sale, held-to-maturity, and trading securities. Our investment portfolio consists of stocks, bonds, options, mutual funds, money market funds, or exchange-traded products that replicate the model portfolios and strategies created by Morningstar. These investment accounts may also include exchange-traded products where Morningstar is an index provider.

Goodwill and Other Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The following table shows the changes in our goodwill balances from December 31, 2018 to June 30, 2019:



	(in millions)
Balance as of December 31, 2018	$	556.7
Foreign currency translation	(0.2		)
Balance as of June 30, 2019	$	556.5

Schedule of Intangible Assets

The following table summarizes our intangible assets:



	As of June 30, 2019								As of December 31, 2018
(in millions)	Gross		Accumulated Amortization			Net		Weighted Average Useful Life (years)	Gross		Accumulated Amortization			Net		Weighted Average Useful Life (years)
Intellectual property	$	30.8	$	(29.6	)	$	1.2	9	$	30.8	$	(29.2	)	$	1.6	9
Customer-related assets	154.0		(115.3		)	38.7		12	153.0		(111.7		)	41.3		12
Supplier relationships	0.2		(0.1		)	0.1		20	0.2		(0.1		)	0.1		20
Technology-based assets	126.9		(102.5		)	24.4		7	126.9		(96.3		)	30.6		7
Non-competition agreements	2.4		(2.1		)	0.3		5	2.4		(2.1		)	0.3		5
Total intangible assets	$	314.3	$	(249.6	)	$	64.7	10	$	313.3	$	(239.4	)	$	73.9	10

Schedule of Intangible Asset, Amortization Expense

The following table summarizes our amortization expense related to intangible assets:



	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
Amortization expense	$	4.9	$	5.2	$	9.8	$	10.5

Schedule of Expected Amortization Expense

We expect intangible amortization expense for the remainder of 2019 and subsequent years as follows:



	(in millions)
Remainder of 2019 (from July 1 through December 31)	$	9.4
2020	16.2
2021	12.8
2022	5.0
2023	5.0
Thereafter	16.3

Our estimates of future amortization expense for intangible assets may be affected by acquisitions, divestitures, changes in the estimated average useful lives, and foreign currency translation.

Income Per Share (Tables)

6 Months Ended

Jun. 30, 2019

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table shows how we reconcile our net income and the number of shares used in computing basic and diluted net income per share:



	Three months ended June 30,				Six months ended June 30,
(in millions, except per share amounts)	2019		2018		2019		2018
Basic net income per share:
Consolidated net income	$	42.1	$	41.8	$	75.3	$	83.7

Weighted average common shares outstanding	42.7		42.6		42.7		42.6

Basic net income per share	$	0.99	$	0.98	$	1.77	$	1.97

Diluted net income per share:
Consolidated net income	$	42.1	$	41.8	$	75.3	$	83.7

Weighted average common shares outstanding	42.7		42.6		42.7		42.6
Net effect of dilutive stock options, restricted stock units, performance share awards, and market stock units	0.4		0.4		0.4		0.4
Weighted average common shares outstanding for computing diluted income per share	43.1		43.0		43.1		43.0

Diluted net income per share	$	0.98	$	0.97	$	1.75	$	1.95

Revenue (Tables)

6 Months Ended

Jun. 30, 2019

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

The following table presents our revenue disaggregated by revenue type. Sales and usage-based taxes are excluded from revenue.



	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
License-based	$	200.9	$	184.3	$	396.4	$	362.9
Asset-based	52.6		48.7		101.5		99.4
Transaction-based	20.4		19.4		34.9		33.6
Consolidated revenue	$	273.9	$	252.4	$	532.8	$	495.9

Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction

We expect to recognize revenue related to our contract liabilities for the remainder of 2019 and subsequent years as follows:



(in millions)	As of June 30, 2019
Remainder of 2019 (from July 1 through December 31)	$	278.7
2020	184.4
2021	50.9
2022	15.3
2023	7.0
Thereafter	50.4
	$	586.7

Summary of Contract Assets and Change in Deferred Commissions

The following table summarizes our contract assets balance:



(in millions)	As of June 30, 2019		As of December 31, 2018
Accounts receivable, less allowance	$	169.2	$	172.2
Deferred commissions	13.5		14.8
Deferred commissions, non-current	12.5		10.3
Total contract assets	$	195.2	$	197.3

The following table shows the change in our deferred commissions balance from December 31, 2018 to June 30, 2019:



	(in millions)
Balance as of December 31, 2018	$	25.1
Commissions earned and capitalized	10.5
Amortization of capitalized amounts	(9.6		)
Balance as of June 30, 2019	$	26.0

Segment and Geographical Area Information (Tables)

6 Months Ended

Jun. 30, 2019

Segment Reporting [Abstract]

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

The tables below summarize our revenue and long-lived assets, which includes property, equipment, and capitalized software, net and operating lease assets, by geographical area:



Revenue by geographical area
	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
United States	$	208.0	$	187.8	$	403.1	$	367.3

United Kingdom	18.8		18.4		36.9		36.7
Continental Europe	20.9		20.3		41.3		40.2
Australia	10.0		10.8		19.5		21.3
Canada	7.8		7.5		15.7		15.2
Asia	6.8		6.1		13.1		12.2
Other	1.6		1.5		3.2		3.0
Total International	65.9		64.6		129.7		128.6

Consolidated revenue	$	273.9	$	252.4	$	532.8	$	495.9



Property, equipment, and capitalized software, net by geographical area

(in millions)	As of June 30, 2019		As of December 31, 2018
United States	$	122.9	$	126.4

United Kingdom	3.5		3.8
Continental Europe	1.2		1.3
Australia	4.6		5.0
Canada	0.3		0.3
Asia	7.3		6.5
Other	0.6		0.2
Total International	17.5		17.1

Consolidated property, equipment, and capitalized software, net	$	140.4	$	143.5



Operating lease assets by geographical area

(in millions)	As of June 30, 2019		As of December 31, 2018
United States	$	65.9	$	—

United Kingdom	6.1		—
Continental Europe	4.9		—
Australia	6.1		—
Canada	2.7		—
Asia	25.2		—
Other	0.9		—
Total International	45.9		—

Consolidated operating lease assets	$	111.8	$	—

As of December 31, 2018, there were no operating lease assets as Topic 842 became effective for the Company on January 1, 2019.

The long-lived asset by geographical area does not include deferred commissions, non-current as the balance is not significant.

Leases (Tables)

6 Months Ended

Jun. 30, 2019

Leases [Abstract]

Assets and Liabilities, Lessee

The following table summarizes the weighted-average lease terms and weighted-average discount rates for our operating leases:



	As of June 30, 2019
Weighted-average remaining lease term (in years)	5.71

Weighted-average discount rate	3.98	%

The following table summarizes our operating assets and lease liabilities:



Leases (in millions)	Balance Sheet Classification	As of June 30, 2019
Assets
Operating	Operating lease assets	$	111.8

Liabilities
Current
Operating	Operating lease liabilities	$	29.6
Non-current
Operating	Operating lease liabilities, non-current	109.4
Total lease liabilities		$	139.0

Lessee, Operating Lease, Liability, Maturity

The following table shows our minimum future lease commitments due in each of the next five years and thereafter for operating leases:



Minimum Future Lease Commitments (in millions)	Operating Leases
Remainder of 2019 (July 1 through December 31)	$	17.2
2020	35.2
2021	31.2
2022	19.2
2023	15.3
Thereafter	38.8
Total lease payments	156.9
Adjustment for discount to present value	17.9
Total	$	139.0

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Share-based Payment Arrangement [Abstract]

Schedule Of Compensation Cost By Expense Category

The following table summarizes the stock-based compensation expense included in each of our operating expense categories:



	Three months ended June 30,				Six months ended June 30,
(in millions)	2019		2018		2019		2018
Cost of revenue	$	3.7	$	3.2	$	6.8	$	5.9
Sales and marketing	1.4		0.9		2.9		1.7
General and administrative	7.4		5.9		12.8		9.0
Total stock-based compensation expense	$	12.5	$	10.0	$	22.5	$	16.6

Income Taxes (Tables)

6 Months Ended

Jun. 30, 2019

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

The following table shows our effective tax rate for the three and six months ended June 30, 2019 and June 30, 2018:



	Three months ended June 30,						Six months ended June 30,
(in millions)	2019			2018			2019			2018
Income before income taxes and equity in net income (loss) of unconsolidated entities	$	53.1		$	55.0		$	99.3		$	111.8
Equity in net income (loss) of unconsolidated entities	0.7			(0.4		)	(0.8		)	(1.9		)
Total	$	53.8		$	54.6		$	98.5		$	109.9
Income tax expense	$	11.7		$	12.8		$	23.2		$	26.2
Effective tax rate	21.7		%	23.4		%	23.6		%	23.8		%

Schedule of Gross Unrecognized Tax Benefits

The table below provides information regarding our gross unrecognized tax benefits as of June 30, 2019 and December 31, 2018, as well as the effect these gross unrecognized tax benefits would have on our income tax expense, if they were recognized.



(in millions)	As of June 30, 2019		As of December 31, 2018
Gross unrecognized tax benefits	$	13.7	$	13.1
Gross unrecognized tax benefits that would affect income tax expense	13.7		13.1
Decrease in income tax expense upon recognition of gross unrecognized tax benefits	13.3		12.6

Schedule of Liabilities for Unrecognized Tax Benefits

Our Unaudited Condensed Consolidated Balance Sheets include the following liabilities for unrecognized tax benefits. These amounts include interest and penalties, less any associated tax benefits.



Liabilities for Unrecognized Tax Benefits (in millions)	As of June 30, 2019		As of December 31, 2018
Current liability	$	6.6	$	6.6
Non-current liability	8.0		7.1
Total liability for unrecognized tax benefits	$	14.6	$	13.7

Summary of Significant Accounting Policies (Impact of Adoption of Topic 842) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 111.8		$ 0.0
Operating lease liabilities	139.0
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 111.8	$ 118.8
Operating lease liabilities		145.8
Reclassification of deferred rent liabilities		$ 27.9

Credit Arrangements (Details) - USD ($)	6 Months Ended
Credit Arrangements (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Outstanding principal balance	$ 15,000,000.0	$ 70,000,000.0
Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit facility borrowing capacity	300,000,000.0
Outstanding principal balance	15,000,000.0
Borrowing availability	285,000,000.0
Letter of Credit
Line of Credit Facility [Line Items]
Credit facility borrowing capacity	$ 25,000,000.0
London Interbank Offered Rate (LIBOR) \| Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)	1.00%
Minimum
Line of Credit Facility [Line Items]
Minimum consolidated interest coverage ratio	3.00
Minimum \| London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)	1.00%
Minimum \| Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)	2.00%
Maximum
Line of Credit Facility [Line Items]
Maximum consolidated leverage ratio	3.00
Maximum \| London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)	1.75%
Maximum \| Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (percent)	2.75%

Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, impairment loss	$ 0.0	$ 0.0
Goodwill [Roll Forward]
Goodwill, Beginning Balance	556.7
Foreign currency translation	(0.2)
Goodwill, Ending Balance	$ 556.5

Goodwill and Other Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross	$ 314.3	$ 313.3
Accumulated Amortization	(249.6)	(239.4)
Intangible assets, Net	$ 64.7	$ 73.9
Weighted-Average Useful Life (years)	10 years	10 years
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Gross	$ 30.8	$ 30.8
Accumulated Amortization	(29.6)	(29.2)
Intangible assets, Net	$ 1.2	$ 1.6
Weighted-Average Useful Life (years)	9 years	9 years
Customer-related assets
Finite-Lived Intangible Assets [Line Items]
Gross	$ 154.0	$ 153.0
Accumulated Amortization	(115.3)	(111.7)
Intangible assets, Net	$ 38.7	$ 41.3
Weighted-Average Useful Life (years)	12 years	12 years
Supplier relationships
Finite-Lived Intangible Assets [Line Items]
Gross	$ 0.2	$ 0.2
Accumulated Amortization	(0.1)	(0.1)
Intangible assets, Net	$ 0.1	$ 0.1
Weighted-Average Useful Life (years)	20 years	20 years
Technology-based assets
Finite-Lived Intangible Assets [Line Items]
Gross	$ 126.9	$ 126.9
Accumulated Amortization	(102.5)	(96.3)
Intangible assets, Net	$ 24.4	$ 30.6
Weighted-Average Useful Life (years)	7 years	7 years
Non-competition agreements
Finite-Lived Intangible Assets [Line Items]
Gross	$ 2.4	$ 2.4
Accumulated Amortization	(2.1)	(2.1)
Intangible assets, Net	$ 0.3	$ 0.3
Weighted-Average Useful Life (years)	5 years	5 years

Goodwill and Other Intangible Assets (Amortization Expense) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 4.9	$ 5.2	$ 9.8	$ 10.5
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2019 (from July 1 through December 31)	9.4		9.4
2019	16.2		16.2
2020	12.8		12.8
2021	5.0		5.0
2022	5.0		5.0
Thereafter	$ 16.3		$ 16.3

Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share, Basic [Abstract]
Consolidated net income	$ 42.1	$ 33.2	$ 41.8	$ 41.9	$ 75.3	$ 83.7
Weighted average common shares outstanding	42.7		42.6		42.7	42.6
Basic net income per share attributable to Morningstar, Inc.	$ 0.99		$ 0.98		$ 1.77	$ 1.97
Earnings Per Share, Diluted [Abstract]
Consolidated net income	$ 42.1		$ 41.8		$ 75.3	$ 83.7
Weighted average common shares outstanding	42.7		42.6		42.7	42.6
Net effect of dilutive stock options and restricted stock units	0.4		0.4		0.4	0.4
Weighted average common shares outstanding for computing diluted income per share	43.1		43.0		43.1	43.0
Diluted net income per share attributable to Morningstar, Inc.	$ 0.98		$ 0.97		$ 1.75	$ 1.95

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

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+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References

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+ Details

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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+ Details

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Consolidated revenue	$ 273.9	$ 252.4	$ 532.8	$ 495.9
License-based
Disaggregation of Revenue [Line Items]
Consolidated revenue	200.9	184.3	396.4	362.9
Asset-based
Disaggregation of Revenue [Line Items]
Consolidated revenue	52.6	48.7	101.5	99.4
Transaction-based
Disaggregation of Revenue [Line Items]
Consolidated revenue	$ 20.4	$ 19.4	$ 34.9	$ 33.6

Revenue (Disaggregation of Revenue, Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues	$ 273.9	$ 252.4	$ 532.8	$ 495.9
Licensed-based Revenue
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues	$ 200.9	184.3	$ 396.4	362.9
Licensed-based Revenue \| Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	12 months		12 months
Licensed-based Revenue \| Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	36 months		36 months
Asset-based Revenue
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenues	$ 52.6	$ 48.7	$ 101.5	$ 99.4
Asset-based Revenue \| Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	12 months		12 months
Asset-based Revenue \| Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue performance period	36 months		36 months

Revenue (Contract Liabilities, Performance Obligation Narrative) (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Increase in contract liabilities from cash payments received	$ 37.3
Revenues recognized	$ 156.2

Revenue (Contract Liabilities, Additional Information Narrative) (Details) $ in Millions	Jun. 30, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Contract liability	$ 247.3

Revenue (Contract Liabilities, Expected Recognition) (Details) $ in Millions	Jun. 30, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	$ 586.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	278.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	184.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	50.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	15.3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	7.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	$ 50.4

Revenue (Summary of Contract Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Accounts receivable, less allowance	$ 169.2	$ 172.2
Deferred commissions	13.5	14.8
Deferred commissions, non-current	12.5	10.3
Total contract assets	$ 195.2	$ 197.3

Revenue (Change in Deferred Commissions) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Balance as of December 31, 2017	$ 25.1
Commissions earned and capitalized	10.5
Amortization of capitalized amounts	(9.6)
Balance as of June 30, 2019	$ 26.0

Segment and Geographical Area Information (External Revenue and Long-Lived Assets) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	$ 273.9	$ 252.4	$ 532.8	$ 495.9
Long-lived assets	140.4		140.4		$ 143.5
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	208.0	187.8	403.1	367.3
Long-lived assets	122.9		122.9		126.4
Total International
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	65.9	64.6	129.7	128.6
Long-lived assets	17.5		17.5		17.1
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	18.8	18.4	36.9	36.7
Long-lived assets	3.5		3.5		3.8
Continental Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	20.9	20.3	41.3	40.2
Long-lived assets	1.2		1.2		1.3
Australia
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	10.0	10.8	19.5	21.3
Long-lived assets	4.6		4.6		5.0
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	7.8	7.5	15.7	15.2
Long-lived assets	0.3		0.3		0.3
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	6.8	6.1	13.1	12.2
Long-lived assets	7.3		7.3		6.5
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
External revenue	1.6	$ 1.5	3.2	$ 3.0
Long-lived assets	$ 0.6		$ 0.6		$ 0.2

Segment, Enterprise-Wide, and Geographical Area Information Segment and Geographical Area Information - Operating Lease Assets by Geographical Area (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	$ 111.8	$ 0.0
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	65.9	0.0
Total International
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	45.9	0.0
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	6.1	0.0
Continental Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	4.9	0.0
Australia
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	6.1	0.0
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	2.7	0.0
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	25.2	0.0
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Consolidated operating lease assets	$ 0.9	$ 0.0

Investments and Fair Value Measurements Investments and Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Investment balances	$ 30.1	$ 26.6

Leases - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
Leases - Narrative (Details) $ in Millions	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease, weighted average remaining lease term	5 years 8 months 15 days	5 years 8 months 15 days
Operating lease expense	$ 7.9	$ 15.8
Variable lease, cost	3.1	5.7
Operating lease payments	8.2	14.4
Operating lease, lease not yet commenced, payments due	$ 24.0	$ 24.0
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, weighted average remaining lease term	1 year	1 year
Operating lease, lease not yet commenced, term of contract	6 months	6 months
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, weighted average remaining lease term	10 years	10 years
Operating lease, lease not yet commenced, term of contract	10 years	10 years

Leases - Assets and Lease Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Assets
Operating lease assets	$ 111.8	$ 0.0
Liabilities
Operating lease liabilities	29.6	0.0
Operating lease liabilities, non-current	109.4	$ 0.0
Total lease liabilities	$ 139.0

Leases - Operating Lease Minimum Future Lease Commitments (Details) $ in Millions	Jun. 30, 2019 USD ($)
Leases [Abstract]
Remainder of 2019	$ 17.2
2020	35.2
2021	31.2
2022	19.2
2023	15.3
Thereafter	38.8
Total lease payments	156.9
Adjustment for discount to present value	17.9
Total	$ 139.0

Leases - Weighted Average Remaining Lease Terms and Discount Rates (Details)	Jun. 30, 2019
Weighted-average remaining lease term (in years)
Weighted-average remaining lease term (in years)	5 years 8 months 15 days
Weighted-average discount rate
Weighted-average discount rate	3.98%

Stock-Based Compensation (Allocation of Stock-Based Compensation Costs by Plan) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 12.5	$ 10.0	$ 22.5	$ 16.6
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	3.7	3.2	6.8	5.9
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1.4	0.9	2.9	1.7
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 7.4	$ 5.9	$ 12.8	$ 9.0

Stock-Based Compensation (Narrative) (Details) - Restricted Stock Units and Performance Share Awards $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 59.1
Expected amortization period (months)	29 months

Income Taxes (Income Tax Reconciliation and Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income before income taxes and equity in net loss of unconsolidated entities	$ 53.1	$ 55.0	$ 99.3	$ 111.8
Equity in net income (loss) of unconsolidated entities	0.7	(0.4)	(0.8)	(1.9)
Total	53.8	54.6	98.5	109.9
Income tax expense	$ 11.7	$ 12.8	$ 23.2	$ 26.2
Effective income tax rate	21.70%	23.40%	23.60%	23.80%
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued [Abstract]
Current liability	$ 6.6		$ 6.6		$ 6.6
Non-current liability	8.0		8.0		7.1
Total liability for unrecognized tax benefits	$ 14.6		$ 14.6		$ 13.7
Concentration Risk [Line Items]
Respective decrease in taxes (as a percent)	1.70%		20.00%
Geographic Concentration Risk \| Cash, Cash Equivalents and Investments \| Total International
Concentration Risk [Line Items]
Percentage of cash, cash equivalents and investments held by operations outside of US			56.00%

Income Taxes (Income Tax Contingency) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits	$ 13.7	$ 13.1
Gross unrecognized tax benefits that would affect income tax expense	13.7	13.1
Decrease in income tax expense upon recognition of gross unrecognized tax benefits	$ 13.3	$ 12.6

Income Taxes (Unrecognized Tax Benefits, Narrative) (Details) $ in Millions	1 Months Ended
	Feb. 28, 2019 USD ($)
Income Tax Disclosure [Abstract]
Foreign earnings repatriated	$ 45.8

Share Repurchase Program (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Equity [Abstract]
Share repurchase program, authorized amount		$ 500,000,000.0
Shares repurchased, program life to date, shares	244,180
Shares repurchased, program life to date, value	$ 25,600,000
Stock repurchase program, remaining authorized repurchase amount	$ 474,400,000

Subsequent Events (Details) - USD ($)	Jul. 02, 2019	Jun. 30, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Credit facilities		$ 15,000,000.0	$ 70,000,000.0
Revolving Credit Facility
Subsequent Event [Line Items]
Credit facilities		15,000,000.0
Credit facility borrowing capacity		300,000,000.0
Letter of Credit
Subsequent Event [Line Items]
Credit facility borrowing capacity		$ 25,000,000.0
Subsequent Event \| Credit Agreement
Subsequent Event [Line Items]
Credit facility borrowing capacity	$ 610,000,000.0
Subsequent Event \| Credit Agreement \| Revolving Credit Facility
Subsequent Event [Line Items]
Credit Agreement, term	5 years
Credit facilities	$ 300,000,000.0
Credit facility borrowing capacity	750,000,000.0
Sublimit for a swingline facility	100,000,000.0
Subsequent Event \| Credit Agreement \| Term Loan Facility
Subsequent Event [Line Items]
Credit facilities	450,000,000.0
Subsequent Event \| Credit Agreement \| Letter of Credit
Subsequent Event [Line Items]
Credit facility borrowing capacity	50,000,000.0
Subsequent Event \| Ratings Acquisition Corp (DBRS)
Subsequent Event [Line Items]
Purchase price of acquisition	$ 669,000,000.0

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 17,000,000.0
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 17,000,000.0