Cover Page - shares	6 Months Ended
Cover Page - shares	Jun. 30, 2021	Jul. 28, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-34501
Entity Registrant Name	JUNIPER NETWORKS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0422528
Entity Address, Address Line One	1133 Innovation Way
Entity Address, City or Town	Sunnyvale,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94089
City Area Code	408
Local Phone Number	745-2000
Title of 12(b) Security	Common Stock, par value $0.00001 per share
Trading Symbol	JNPR
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		325,151,821
Entity Central Index Key	0001043604
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31

Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Total net revenues	$ 1,172.3	$ 1,086.3	$ 2,246.7	$ 2,084.3
Cost of revenues:
Total cost of revenues	490.4	466.7	949.2	885.4
Gross margin	681.9	619.6	1,297.5	1,198.9
Operating expenses:
Research and development	245.8	241.0	500.5	473.5
Sales and marketing	257.8	224.2	510.5	463.4
General and administrative	71.0	59.1	132.1	118.4
Restructuring charges	21.6	4.8	40.9	13.7
Total operating expenses	596.2	529.1	1,184.0	1,069.0
Operating income	85.7	90.5	113.5	129.9
Loss on extinguishment of debt	0.0	0.0	(60.6)	0.0
Other expense, net	(10.9)	(4.4)	(15.9)	(15.5)
Income before income taxes	74.8	86.1	37.0	114.4
Income tax provision	12.8	24.9	6.1	32.8
Net income	$ 62.0	$ 61.2	$ 30.9	$ 81.6
Net income per share:
Basic (in dollars per share)	$ 0.19	$ 0.18	$ 0.09	$ 0.25
Diluted, (in dollars per share)	$ 0.19	$ 0.18	$ 0.09	$ 0.24
Weighted-average shares used to compute net income per share:
Basic (in shares)	324.5	331.0	325.4	330.9
Diluted (in shares)	330.4	333.1	331.5	334.7
Product
Total net revenues	$ 759.2	$ 692.3	$ 1,431.6	$ 1,301.1
Cost of revenues:
Total cost of revenues	350.4	321.7	666.9	590.7
Service
Total net revenues	413.1	394.0	815.1	783.2
Cost of revenues:
Total cost of revenues	$ 140.0	$ 145.0	$ 282.3	$ 294.7

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 62.0	$ 61.2	$ 30.9	$ 81.6
Available-for-sale debt securities:
Change in net unrealized gains, net	1.3	8.7	0.1	5.7
Net realized (gains) and losses reclassified into net income, net	(0.2)	(0.2)	(1.0)	0.3
Net change on available-for-sale debt securities, net	1.1	8.5	(0.9)	6.0
Cash flow hedges:
Change in net unrealized gains and (losses), net of tax benefit (provision) of $7.2 and $(7.3) during the three and six months ended June 30, 2021, respectively, and tax benefit (provision) of $(1.8) and $2.4 for the comparable periods in 2020, respectively	(19.7)	16.1	18.8	(8.8)
Net realized (gains) and losses reclassified into net income, net	(7.2)	6.1	(16.1)	7.5
Net change on cash flow hedges, net	(26.9)	22.2	2.7	(1.3)
Change in foreign currency translation adjustments	0.4	5.6	(1.5)	(9.1)
Other comprehensive income (loss), net	(25.4)	36.3	0.3	(4.4)
Comprehensive income	$ 36.6	$ 97.5	$ 31.2	$ 77.2

Condensed Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Unrealized (loss) gain on cash flow hedges, tax benefit (provision)	$ 7.2	$ (1.8)	$ (7.3)	$ 2.4

Condensed Consolidated Balance Sheets - USD ($)
$ in Millions

Jun. 30, 2021

Dec. 31, 2020

Current assets:

Cash and cash equivalents

$ 986.7

$ 1,361.9

Short-term investments

335.5

412.1

Accounts receivable, net of allowances

768.3

964.1

Inventory*

^[1]

211.5

210.2

Prepaid expenses and other current assets*

^[1]

344.1

322.9

Total current assets

2,646.1

3,271.2

Property and equipment, net

725.1

762.3

Operating lease assets

180.9

184.6

Long-term investments

493.2

656.6

Purchased intangible assets, net

315.3

266.7

Goodwill

3,754.1

3,669.6

Other long-term assets

608.7

567.3

Total assets

8,723.4

9,378.3

Current liabilities:

Accounts payable

259.8

277.0

Accrued compensation

264.2

270.7

Deferred revenue

891.2

867.3

Short-term portion of long-term debt

0.0

421.5

Other accrued liabilities

275.7

324.6

Total current liabilities

1,690.9

2,161.1

Long-term debt

1,694.4

1,705.8

Long-term deferred revenue

440.1

418.5

Long-term income taxes payable

324.5

312.5

Long-term operating lease liabilities

160.7

163.5

Other long-term liabilities

71.9

73.4

Total liabilities

4,382.5

4,834.8

Commitments and contingencies (Note 15)

Stockholders' equity:

Preferred stock, $0.00001 par value; 10.0 shares authorized; none issued and outstanding

0.0

Common stock, $0.00001 par value; 1,000.0 shares authorized; 324.0 shares and 327.7 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively

0.0

Additional paid-in capital

7,042.8

7,156.9

Accumulated other comprehensive income

55.9

55.6

Accumulated deficit

(2,757.8)

(2,669.0)

Total stockholders' equity

4,340.9

4,543.5

Total liabilities and stockholders' equity

$ 8,723.4

$ 9,378.3

[1]	The prior period amount has been reclassified to conform to the current period presentation. Previously, Inventory was reported as Prepaid expenses and other current assets.

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock - par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock - shares authorized (in shares)	10,000,000.0	10,000,000.0
Preferred stock - issued (in shares)	0	0
Preferred stock - outstanding (in shares)	0	0
Common stock - par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock - shares authorized (in shares)	1,000,000,000.0	1,000,000,000.0
Common stock - issued (in shares)	324,000,000.0	327,700,000
Common stock - outstanding (in shares)	324,000,000.0	327,700,000

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 30.9	$ 81.6
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense	108.0	86.0
Depreciation, amortization, and accretion	120.9	106.0
Operating lease assets expense	24.8	21.0
Loss on extinguishment of debt	60.6	0.0
Other	4.7	3.8
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable, net	195.1	124.7
Prepaid expenses and other assets	(55.4)	(38.7)
Accounts payable	(18.5)	20.6
Accrued compensation	(4.4)	(11.7)
Income taxes payable	(3.4)	0.9
Other accrued liabilities	(71.8)	(14.2)
Deferred revenue	45.5	(10.2)
Net cash provided by operating activities	437.0	369.8
Cash flows from investing activities:
Purchases of property and equipment	(41.1)	(43.8)
Purchases of available-for-sale debt securities	(314.4)	(546.2)
Proceeds from sales of available-for-sale debt securities	352.3	156.9
Proceeds from maturities and redemptions of available-for-sale debt securities	200.5	622.7
Purchases of equity securities	(6.1)	(3.6)
Proceeds from sales of equity securities	5.0	3.7
Payments for business acquisitions, net of cash and cash equivalents acquired	(175.0)	(0.2)
Other	(0.6)	0.0
Net cash provided by investing activities	20.6	189.5
Cash flows from financing activities:
Repurchase and retirement of common stock	(243.1)	(205.3)
Proceeds from issuance of common stock	28.9	27.6
Payment of dividends	(129.9)	(131.8)
Payment of debt	(423.8)	0.0
Payment for debt extinguishment costs	(58.3)	0.0
Other	(3.4)	4.8
Net cash used in financing activities	(829.6)	(304.7)
Effect of foreign currency exchange rates on cash, cash equivalents, and restricted cash	(1.6)	(9.9)
Net (decrease) increase in cash, cash equivalents, and restricted cash	(373.6)	244.7
Cash, cash equivalents, and restricted cash at beginning of period	1,383.0	1,276.5
Cash, cash equivalents, and restricted cash at end of period	$ 1,009.4	$ 1,521.2

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Shares	Common Stock and Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance (in shares) at Dec. 31, 2019		335.9
Balance at Dec. 31, 2019	$ 4,610.6		$ 7,370.5	$ (18.5)	$ (2,741.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	81.6				81.6
Other comprehensive income (loss), net	(4.4)			(4.4)
Issuance of common stock (in shares)		6.4
Issuance of common stock	27.6		27.6
Repurchase and retirement of common stock (in shares)		(10.6)
Repurchase and retirement of common stock	(245.3)		(136.6)		(108.7)
Purchase of forward contract under accelerated share repurchase program ("ASR")	40.0
Share-based compensation expense	86.0		86.0
Payments of cash dividends	(131.8)		(131.8)
Balance (in shares) at Jun. 30, 2020		331.7
Balance at Jun. 30, 2020	4,464.3		7,255.7	(22.9)	(2,768.5)
Balance (in shares) at Mar. 31, 2020		331.0
Balance at Mar. 31, 2020	4,390.7		7,281.3	(59.2)	(2,831.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	61.2				61.2
Other comprehensive income (loss), net	36.3			36.3
Issuance of common stock (in shares)		0.8
Issuance of common stock	0.5		0.5
Repurchase and retirement of common stock (in shares)		(0.1)
Repurchase and retirement of common stock	(2.1)		(3.8)		1.7
Share-based compensation expense	44.0		44.0
Payments of cash dividends	(66.3)		(66.3)
Balance (in shares) at Jun. 30, 2020		331.7
Balance at Jun. 30, 2020	4,464.3		7,255.7	(22.9)	(2,768.5)
Balance (in shares) at Dec. 31, 2020		327.7
Balance at Dec. 31, 2020	4,543.5		7,156.9	55.6	(2,669.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	30.9				30.9
Other comprehensive income (loss), net	0.3			0.3
Issuance of common stock (in shares)		5.8
Issuance of common stock	31.6		31.6
Repurchase and retirement of common stock (in shares)		(9.5)
Repurchase and retirement of common stock	(243.1)		(123.4)		(119.7)
Share-based compensation expense	107.6		107.6
Payments of cash dividends	(129.9)		(129.9)
Balance (in shares) at Jun. 30, 2021		324.0
Balance at Jun. 30, 2021	4,340.9		7,042.8	55.9	(2,757.8)
Balance (in shares) at Mar. 31, 2021		327.4
Balance at Mar. 31, 2021	4,429.6		7,110.9	81.3	(2,762.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	62.0				62.0
Other comprehensive income (loss), net	(25.4)			(25.4)
Issuance of common stock (in shares)		0.8
Issuance of common stock	0.5		0.5
Repurchase and retirement of common stock (in shares)		(4.2)
Repurchase and retirement of common stock	(111.2)		(54.0)		(57.2)
Share-based compensation expense	50.1		50.1
Payments of cash dividends	(64.7)		(64.7)
Balance (in shares) at Jun. 30, 2021		324.0
Balance at Jun. 30, 2021	$ 4,340.9		$ 7,042.8	$ 55.9	$ (2,757.8)

Condensed Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.20	$ 0.20	$ 0.40	$ 0.40

Basis of Presentation and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Note 1. Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The Condensed Consolidated Financial Statements of Juniper Networks, Inc. (the “Company” or “Juniper”) were prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information. Accordingly, they do not include all information and footnotes required by U.S. GAAP for complete financial statements. The Condensed Consolidated Balance Sheet as of December 31, 2020 has been derived from the audited Consolidated Financial Statements at that date. In the opinion of management, all adjustments, including normal recurring accruals, considered necessary for a fair presentation have been included. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021, or any future period. These Condensed Consolidated Financial Statements and accompanying notes should be read in conjunction with the audited Consolidated Financial Statements and accompanying notes in the Company's Annual Report on Form 10-K for the year ended December 31, 2020 (the "Form 10-K"). We have evaluated all subsequent events through the date these condensed consolidated financial statements were issued. The preparation of the financial statements and related disclosures in accordance with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the amounts reported in the Condensed Consolidated Financial Statements and the accompanying notes. Actual results could differ materially from those estimates under different assumptions or conditions. Summary of Significant Accounting Policies Except for the change in certain policies upon adoption of the accounting standards described below, there have been no significant changes to the Company's significant accounting policies described in Note 1, Description of Business, Basis of Presentation and Significant Accounting Policies, in Notes to Consolidated Financial Statements in Item 8 of Part II of the Form 10-K for the fiscal year ended December 31, 2020. Recently Adopted Accounting Standards Simplifying the Accounting for Income Taxes: On January 1, 2021, the Company adopted ASU No. 2019-12 (Topic 740) Income Taxes — Simplifying the Accounting for Income Taxes, which enhances and simplifies various aspects related to accounting for income taxes. Upon adoption, the standard did not have a material impact on the Condensed Consolidated Financial Statements. Recent Accounting Standards Not Yet Adopted Reference Rate Reform: In March 2020, the FASB issued ASU No. 2020-04 (Topic 848), Reference Rate Reform - Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides temporary optional expedients and exceptions to the existing guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative reference rates, such as the Secured Overnight Financing Rate. In January 2021, the FASB issued ASU No. 2021-01 (Topic 848), Reference Rate Reform: Scope, which refines the scope of Topic 848 and clarifies some of its guidance. The amendments were effective upon issuance and may be applied through December 31, 2022, to any new or amended contracts, hedging relationships, and other transactions that reference LIBOR. The Company is currently evaluating the impact of the transition and disclosure requirements of the standard on its Condensed Consolidated Financial Statements.

Business Combinations

6 Months Ended

Jun. 30, 2021

Business Combinations [Abstract]

Business Combinations

Note 2. Business Combinations

On January 27, 2021, the Company acquired 100% ownership of Apstra, Inc. ("Apstra"), a company that provides intent-based networking, open programmability and automated closed loop assurance for the management of data center networks. The purchase consideration was $179.4 million, consisting of $176.7 million in cash and $2.7 million in share-based awards attributable to services prior to the acquisition. The acquisition is expected to expand upon the Company's data center networking portfolio to advance its vision to transform data center operations.

The following table summarizes the preliminary fair value of the assets acquired and liabilities assumed at the acquisition date (in millions):


	Amount
Cash and cash equivalents	$	1.8
Goodwill	84.0
Intangible assets	87.8
Other assets acquired	12.6
Liabilities assumed	(6.8)
Total	$	179.4

The goodwill recognized in connection with the acquisition is primarily attributable to anticipated synergies from future growth and will not be deductible for income tax purposes.

The following table summarizes the fair value of the separately identifiable intangible assets at the time of acquisition (in millions):


	Amount
Intangible assets(*):
Developed technology	$	80.5
Customer relationships	7.3

Total intangible assets acquired	$	87.8

________________________________

(*) Estimated useful life assigned to Developed Technology and Customer Relationships is 5 and 1.5 years, respectively.

Acquisition-related costs were not material during the three and six months ended June 30, 2021, and were expensed in the period incurred within general and administrative expense in the Company's Condensed Consolidated Statements of Operations.

The Company's Condensed Consolidated Financial Statements include the operating results of this business combination from the date of acquisition. Pro forma results of operations for this acquisition have not been presented, as the financial impact to the Company's consolidated results of operations is not material. The preliminary purchase price allocation is subject to potential measurement period adjustments relating to certain tax and legal matters.

Cash Equivalents and Investments

6 Months Ended

Jun. 30, 2021

Cash Equivalents and Investments [Abstract]

Cash Equivalents and Investments

Note 3. Cash Equivalents and Investments

Investments in Available-for-Sale Debt Securities

The following table summarizes the Company's unrealized gains and losses and fair value of investments designated as available-for-sale debt securities as of June 30, 2021 and December 31, 2020 (in millions):


	As of June 30, 2021								As of December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Fixed income securities:
Asset-backed securities	$	90.8	$	0.1	$	(0.1)	$	90.8	$	76.5	$	0.2	$	—	$	76.7
Certificates of deposit	15.3		—		—		15.3		32.9		—		—		32.9
Commercial paper	78.2		—		—		78.2		89.3		—		—		89.3
Corporate debt securities	482.8		2.8		(0.2)		485.4		632.0		5.5		(0.1)		637.4
Foreign government debt securities	7.6		—		—		7.6		4.6		—		—		4.6
Time deposits	64.2		—		—		64.2		255.6		—		—		255.6
U.S. government agency securities	26.6		0.1		—		26.7		65.3		0.2		—		65.5
U.S. government securities	146.6		0.4		—		147.0		232.8		1.0		—		233.8
Total fixed income securities	912.1		3.4		(0.3)		915.2		1,389.0		6.9		(0.1)		1,395.8
Privately-held debt and redeemable preferred stock securities	21.2		39.9		—		61.1		18.3		37.4		—		55.7
Total available-for-sale debt securities	$	933.3	$	43.3	$	(0.3)	$	976.3	$	1,407.3	$	44.3	$	(0.1)	$	1,451.5

Reported as:
Cash equivalents	$	93.7	$	—	$	—	$	93.7	$	333.7	$	—	$	—	$	333.7
Short-term investments	327.2		1.1		—		328.3		404.3		1.2		—		405.5
Long-term investments	491.2		2.3		(0.3)		493.2		651.0		5.7		(0.1)		656.6
Other long-term assets	21.2		39.9		—		61.1		18.3		37.4		—		55.7
Total	$	933.3	$	43.3	$	(0.3)	$	976.3	$	1,407.3	$	44.3	$	(0.1)	$	1,451.5

The following table presents the contractual maturities of the Company's total fixed income securities as of June 30, 2021 (in millions):


	Amortized Cost		Estimated Fair Value
Due in less than one year	$	420.9	$	422.0
Due between one and five years	491.2		493.2
Total	$	912.1	$	915.2

For available-for-sale debt securities that have unrealized losses, the Company assesses impairment by evaluating various factors, including whether (i) it has the intention to sell any of these investments and (ii) whether it is more likely than not that it will be required to sell any of these investments before recovery of the entire amortized cost basis. The Company periodically assesses performance indicators of the investment by evaluating various factors such as (i) changes in the credit ratings and (ii) review of the issuer. As of June 30, 2021, the Company's unrealized loss of $0.3 million resulted from 147 investments that

were in an unrealized loss position for less than 12 months. The gross unrealized losses related to these investments were primarily due to changes in market interest rates. The Company anticipates that it will recover the entire amortized cost basis of such available-for-sale debt securities and has determined that no allowance for credit losses was required to be recognized during the three and six months ended June 30, 2021 and June 30, 2020.

During the three and six months ended June 30, 2021 and June 30, 2020, there were no material gross realized gains or losses from available-for-sale debt securities.

Investments in Equity Securities

The following table presents the Company's investments in equity securities as of June 30, 2021 and December 31, 2020 (in millions):


	As of
	June 30, 2021		December 31, 2020
Equity investments with readily determinable fair value:
Money market funds	$	387.1	$	536.6
Mutual funds	31.9		29.3
Publicly-traded equity securities	7.2		6.6
Equity investments without readily determinable fair value:	145.1		146.2
Total equity securities	$	571.3	$	718.7

Reported as:
Cash equivalents	$	370.3	$	519.8
Short-term investments	7.2		6.6
Prepaid expenses and other current assets	10.4		9.9
Other long-term assets	183.4		182.4
Total	$	571.3	$	718.7

For the three and six months ended June 30, 2021 and June 30, 2020, there were no material unrealized gains or losses recognized for equity investments.

Restricted Cash and Investments

The Company has restricted cash and investments for: (i) amounts held in escrow accounts, as required in connection with certain acquisitions completed primarily in 2020 and 2021; (ii) amounts held under the Company's short-term disability plan in California; and (iii) amounts under the Company's non-qualified deferred compensation plan for senior-level employees. Restricted investments consist of equity investments. As of June 30, 2021, the carrying value of restricted cash and investments was $71.3 million, of which $29.4 million was included in prepaid expenses and other current assets, and $41.9 million was included in other long-term assets on the Condensed Consolidated Balance Sheet.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash included in the Condensed Consolidated Balance Sheets as of June 30, 2021 and December 31, 2020 (in millions):


	As of
	June 30, 2021		December 31, 2020
Cash and cash equivalents	$	986.7	$	1,361.9
Restricted cash included in Prepaid expenses and other current assets	19.0		19.2
Restricted cash included in Other long-term assets	3.7		1.9
Total cash, cash equivalents, and restricted cash	$	1,009.4	$	1,383.0

Fair Value Measurements

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

Note 4. Fair Value Measurements

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table provides a summary of assets and liabilities measured at fair value on a recurring basis and as reported in the Condensed Consolidated Balance Sheets as of June 30, 2021 and December 31, 2020 (in millions):


	Fair Value Measurements at June 30, 2021								Fair Value Measurements at December 31, 2020
	Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total
Assets:
Available-for-sale debt securities:
Asset-backed securities	$	—	$	90.8	$	—	$	90.8	$	—	$	76.7	$	—	$	76.7
Certificates of deposit	—		15.3		—		15.3		—		32.9		—		32.9
Commercial paper	—		78.2		—		78.2		—		89.3		—		89.3
Corporate debt securities	—		485.4		—		485.4		—		637.4		—		637.4
Foreign government debt securities	—		7.6		—		7.6		—		4.6		—		4.6
Time deposits	—		64.2		—		64.2		—		255.6		—		255.6
U.S. government agency securities	—		26.7		—		26.7		—		65.5		—		65.5
U.S. government securities	102.9		44.1		—		147.0		140.0		93.8		—		233.8
Privately-held debt and redeemable preferred stock securities	—		—		61.1		61.1		—		—		55.7		55.7
Total available-for-sale debt securities	102.9		812.3		61.1		976.3		140.0		1,255.8		55.7		1,451.5
Equity securities:
Money market funds	387.1		—		—		387.1		536.6		—		—		536.6
Mutual funds	31.9		—		—		31.9		29.3		—		—		29.3
Publicly-traded equity securities	7.2		—		—		7.2		6.6		—		—		6.6
Total equity securities	426.2		—		—		426.2		572.5		—		—		572.5
Derivative assets:
Foreign exchange contracts	—		29.2		—		29.2		—		38.0		—		38.0
Interest rate contracts	—		61.7		—		61.7		—		51.0		—		51.0
Total derivative assets	—		90.9		—		90.9		—		89.0		—		89.0
Total assets measured at fair value on a recurring basis	$	529.1	$	903.2	$	61.1	$	1,493.4	$	712.5	$	1,344.8	$	55.7	$	2,113.0
Liabilities:
Derivative liabilities:
Foreign exchange contracts	$	—	$	(5.9)	$	—	$	(5.9)	$	—	$	(0.5)	$	—	$	(0.5)
Total derivative liabilities	—		(5.9)		—		(5.9)		—		(0.5)		—		(0.5)
Total liabilities measured at fair value on a recurring basis	$	—	$	(5.9)	$	—	$	(5.9)	$	—	$	(0.5)	$	—	$	(0.5)


	Fair Value Measurements at June 30, 2021								Fair Value Measurements at December 31, 2020
	Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total

Total assets, reported as:
Cash equivalents	$	370.3	$	93.7	$	—	$	464.0	$	519.8	$	333.7	$	—	$	853.5
Short-term investments	85.7		249.8		—		335.5		101.0		311.1		—		412.1
Long-term investments	24.4		468.8		—		493.2		45.6		611.0		—		656.6
Prepaid expenses and other current assets	10.5		22.5		—		33.0		9.9		28.0		—		37.9
Other long-term assets	38.2		68.4		61.1		167.7		36.2		61.0		55.7		152.9
Total assets measured at fair value	$	529.1	$	903.2	$	61.1	$	1,493.4	$	712.5	$	1,344.8	$	55.7	$	2,113.0

Total liabilities, reported as:
Other accrued liabilities	$	—	$	(2.9)	$	—	$	(2.9)	$	—	$	(0.3)	$	—	$	(0.3)
Other long-term liabilities	—		(3.0)		—		(3.0)		—		(0.2)		—		(0.2)
Total liabilities measured at fair value on a recurring basis	$	—	$	(5.9)	$	—	$	(5.9)	$	—	$	(0.5)	$	—	$	(0.5)

The Company's Level 2 available-for-sale debt securities are priced using quoted market prices for similar instruments or non-binding market prices that are corroborated by observable market data. The Company uses inputs such as actual trade data, benchmark yields, broker/dealer quotes, or alternative pricing sources with reasonable levels of price transparency, which are obtained from quoted market prices, independent pricing vendors, or other sources, to determine the ultimate fair value of these assets. The Company's derivative instruments are classified as Level 2, as they are not actively traded and are valued using pricing models that use observable market inputs. During the three and six months ended June 30, 2021, the Company had no transfers into or out of Level 3 of the fair value hierarchy of its assets or liabilities measured at fair value.

The Company's privately-held debt and redeemable preferred stock securities are classified as Level 3 assets due to the lack of observable inputs to determine fair value. The Company estimates the fair value of its privately-held debt and redeemable preferred stock securities on a recurring basis using an analysis of the financial condition and near-term prospects of the investee, including recent valuations at the time of financing activities and the investee's capital structure. During the three and six months ended June 30, 2021, there were no significant activities related to privately-held debt and redeemable preferred stock securities.

Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis

The Company's investments in equity securities without readily determinable fair value are classified as Level 3 assets due to the lack of observable inputs to determine fair value. The Company estimates the fair value on a nonrecurring basis (i.e. when an observable transaction occurs) using an analysis of the financial condition and near-term prospects of the investee, including recent financing activities and the investee's capital structure. As of June 30, 2021, there have been no material upward or downward adjustments for price changes to the equity securities without readily determinable fair value.

Certain of the Company's assets, including intangible assets and goodwill, are measured at fair value on a nonrecurring basis. There were no significant impairment charges recognized during the three and six months ended June 30, 2021.

As of June 30, 2021 and December 31, 2020, the Company had no liabilities required to be measured at fair value on a nonrecurring basis.

Assets and Liabilities Not Measured at Fair ValueThe carrying amounts of the Company's accounts receivable, accounts payable, and other accrued liabilities approximate fair value due to their short maturities. As of June 30, 2021 and December 31, 2020, the estimated fair value of the Company's total outstanding debt in the Condensed Consolidated Balance Sheets was $1,873.4 million and $2,386.6 million, respectively, based on observable market inputs (Level 2). The net carrying value of a contract manufacturer deposit of $66.4 million, reported within other long-term assets, in the Condensed Consolidated Balance Sheets approximates its fair value as of June 30, 2021. See Note 7, Other Financial Information, for further information on the contract manufacturer deposit.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Derivative Instruments

6 Months Ended

Jun. 30, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments

Note 5. Derivative Instruments

The Company uses derivative instruments to manage a variety of risks, including risks related to fluctuations in foreign currency exchange rates and interest rates on debt instruments. We do not use derivative financial instruments for speculative purposes.

The notional amount of the Company's derivatives is summarized as follows (in millions):


	As of
	June 30, 2021		December 31, 2020
Designated derivatives:
Cash flow hedges:
Foreign currency contracts	$	811.0	$	722.1
Interest rate lock contracts	650.0		650.0
Fair value hedges:
Interest rate swap contracts	600.0		300.0
Total designated derivatives	2,061.0		1,672.1

Non-designated derivatives	125.3		174.1
Total	$	2,186.3	$	1,846.2

The fair value of derivative instruments on the Condensed Consolidated Balance Sheets was as follows:


		As of
	Balance Sheet Classification	June 30, 2021		December 31, 2020
Derivative assets:
Derivatives designated as hedging instruments:
Foreign currency contracts	Other current assets	$	21.4	$	27.8
Foreign currency contracts	Other long-term assets	6.7		10.0
Interest rate lock contracts	Other long-term assets	53.7		30.7
Interest rate swap contracts	Other long-term assets	8.0		20.3
Total derivatives designated as hedging instruments		$	89.8	$	88.8
Derivatives not designated as hedging instruments	Other current assets	1.1		0.2
Total derivative assets		$	90.9	$	89.0
Derivative liabilities:
Derivatives designated as hedging instruments:
Foreign currency contracts	Other accrued liabilities	$	2.7	$	0.2
Foreign currency contracts	Other long-term liabilities	3.0		0.2


Total derivatives designated as hedging instruments		$	5.7	$	0.4
Derivatives not designated as hedging instruments	Other accrued liabilities	0.2		0.1
Total derivative liabilities		$	5.9	$	0.5

Designated Derivatives

The Company uses foreign currency forward contracts to hedge the Company's planned cost of revenues and operating expenses denominated in foreign currencies. These derivatives are designated as cash flow hedges and typically have maturities of thirty-six months or less.

The Company enters into interest rate swaps, designated as fair value hedges, to convert the fixed interest rates of certain Senior Notes to floating interest rates. In April 2021, the Company entered into swaps for an aggregate notional amount of $300.0 million for its fixed-rate 2030 Notes in addition to the swaps entered in 2019 for an aggregate notional amount of $300.0 million for its fixed-rate 2041 Notes. The interest rate swaps will expire within ten years.

In 2020, the Company entered into interest rate locks with large financial institutions, which fix the benchmark interest rates of future debt issuance for an aggregate notional amount of $650.0 million. These contracts are designated as cash flow hedges and are expected to terminate within five years or less.

Effect of Derivative Instruments on the Consolidated Statements of Operations

For cash flow hedges, the Company recognized an unrealized loss of $26.9 million and an unrealized gain of $26.1 million in accumulated other comprehensive income for the effective portion of its derivative instruments for the three and six months ended June 30, 2021, respectively. The Company recognized an unrealized gain of $17.9 million and an unrealized loss of $11.2 million in accumulated other comprehensive income for the effective portion of its derivative instruments for the three and six months ended June 30, 2020, respectively.

For foreign currency forward contracts, the Company reclassified a gain of $8.1 million and $18.1 million out of accumulated other comprehensive income to cost of revenues and operating expenses in the Condensed Consolidated Statements of Operations during the three and six months ended June 30, 2021, respectively, and a loss of $6.9 million and $8.3 million for the comparable periods ended June 30, 2020, respectively. As of June 30, 2021, an estimated $18.7 million of unrealized net gain within accumulated other comprehensive loss is expected to be reclassified into earnings within the next twelve months.

Non-Designated Derivatives

The Company also uses foreign currency forward contracts to mitigate variability in gains and losses generated from the remeasurement of certain monetary assets and liabilities denominated in foreign currencies. These foreign exchange forward contracts typically have maturities of approximately one to four months. The outstanding non-designated derivative instruments are carried at fair value. Changes in the fair value of these derivatives, which were recorded in other expense, net within the Condensed Consolidated Statements of Operations, were not material during the three and six months ended June 30, 2021 and June 30, 2020.

Goodwill and Purchased Intangible Assets

6 Months Ended

Jun. 30, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Purchased Intangible Assets

Note 6. Goodwill and Purchased Intangible Assets

Goodwill

The Company's goodwill activity during the six months ended June 30, 2021 was as follows (in millions):


	Total
December 31, 2020	$	3,669.6
Additions due to business combinations	84.5
June 30, 2021	$	3,754.1

There were no impairments to goodwill during the three and six ended June 30, 2021 and June 30, 2020, respectively.

Purchased Intangible Assets

The Company’s purchased intangible assets, net, were as follows (in millions):


	As of June 30, 2021								As of December 31, 2020
	Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net		Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net
Finite-lived intangible assets:
Technologies and patents	$	903.8	$	(628.9)	$	(55.1)	$	219.8	$	823.5	$	(598.2)	$	(55.1)	$	170.2
Customer relationships	136.3		(91.3)		(2.8)		42.2		129.2		(84.4)		(2.8)		42.0
Trade names and other	9.6		(5.3)		—		4.3		9.6		(4.1)		—		5.5
Total	1,049.7		(725.5)		(57.9)		266.3		962.3		(686.7)		(57.9)		217.7
Indefinite-lived intangible assets:
In-process research and development	49.0		—		—		49.0		49.0		—		—		49.0
Total purchased intangible assets	$	1,098.7	$	(725.5)	$	(57.9)	$	315.3	$	1,011.3	$	(686.7)	$	(57.9)	$	266.7

Amortization expense related to purchased intangible assets with finite lives was $19.8 million and $38.8 million for the three and six months ended June 30, 2021. Amortization expense related to purchased intangible assets with finite lives was $9.4 million and $19.3 million for the three and six months ended June 30, 2020. There were no significant impairment charges related to purchased intangible assets for the three and six months ended June 30, 2021 and June 30, 2020, respectively.

As of June 30, 2021, the estimated future amortization expense of purchased intangible assets with finite lives is as follows (in millions):


Years Ending December 31,	Amount
Remainder of 2021	$	40.3
2022	72.8
2023	66.9
2024	47.4
2025	37.8
Thereafter	1.1
Total	$	266.3

Other Financial Information

6 Months Ended

Jun. 30, 2021

Other Financial Information [Abstract]

Other Financial Information

Note 7. Other Financial Information

Total Inventory

Total inventory consisted of the following (in millions):


	As of
	June 30, 2021		December 31, 2020
Production and service materials	$	167.5	$	158.1
Finished goods	54.8		63.8
Total inventory	$	222.3	$	221.9

Reported as:
Inventory	$	211.5	$	210.2
Other long-term assets	10.8		11.7
Total inventory	$	222.3	$	221.9

Deposit

The Company has a non-interest bearing deposit balance of $66.4 million, net of an unamortized discount balance of $4.7 million, to a contract manufacturer. The discount is calculated based on an imputed interest rate of 5.1% at June 30, 2021. The imputed interest will be amortized over the term of the deposit to interest income along with a corresponding charge to cost of revenues. The deposit is classified as other long-term asset on the Condensed Consolidated Balance Sheets.

Warranties

Changes during the six months ended June 30, 2021 in the Company’s warranty reserve as reported within other accrued liabilities in the Condensed Consolidated Balance Sheets were as follows (in millions):


Balance as of December 31, 2020	$	30.2
Provisions made during the period	19.4

Actual costs incurred during the period	(18.8)

Balance as of June 30, 2021	$	30.8

Revenue

See Note 12, Segments, for disaggregated revenue by product and service, customer vertical, and geographic region.

Product revenue of $14.2 million and $42.9 million included in deferred revenue at January 1, 2021 was recognized during the three and six months ended June 30, 2021, respectively. Service revenue of $212.5 million and $490.2 million included in deferred revenue at January 1, 2021 was recognized during the three and six months ended June 30, 2021, respectively.

The following table summarizes the transaction price for contracts that have not yet been recognized as revenue as of June 30, 2021 and when the Company expects to recognize the amounts as revenue (in millions):


	Revenue Recognition Expected by Period
	Total		Less than 1 year		1-3 years		More than 3 years
Product	$	120.9	$	102.3	$	15.5	$	3.1
Service(*)	1,225.2		798.3		350.2		76.7
Total	$	1,346.1	$	900.6	$	365.7	$	79.8

________________________________

(*) Represents unearned service revenue allocated to the performance obligations not delivered or partially delivered as of June 30, 2021. The unearned service revenue is comprised of deferred revenue and non-cancellable contract revenue, which has not been invoiced yet.

Deferred Commissions

Deferred commissions were $30.6 million as of June 30, 2021. For the three and six months ended June 30, 2021, amortization expense for the deferred commissions was $42.5 million and $82.9 million, and there were no impairment charges recognized.

Other Expense, Net

Other expense, net, consisted of the following (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Interest income	$	3.4	$	9.3	$	7.5	$	24.4
Interest expense	(12.6)		(19.3)		(26.3)		(39.5)
(Loss) gain on investments, net	(1.2)		6.5		2.6		0.7
Other	(0.5)		(0.9)		0.3		(1.1)
Other expense, net	$	(10.9)	$	(4.4)	$	(15.9)	$	(15.5)

Restructuring Charges

6 Months Ended

Jun. 30, 2021

Restructuring and Related Activities [Abstract]

Restructuring Charges

Note 8. Restructuring Charges

During the first quarter of 2021, the Company initiated a restructuring plan (the "2021 Restructuring Plan") driven by recent acquisitions and strategic changes and designed to enable reinvestment in certain key priority areas, which resulted in severance, facility consolidations, contract terminations, and other exit related costs. The 2021 Restructuring Plan activities are expected to be substantially completed during the first half of 2022.

During the three and six months ended June 30, 2021, the Company recorded a $0.9 million benefit and $13.8 million charge related to severance for workforce reductions and $2.3 million and $6.9 million in facility consolidation costs, respectively. During the second quarter of 2021, the Company also recorded $20.2 million in contract termination and other costs, which included $5.3 million in impairment charges associated with the restructuring activities. These costs were reported as restructuring charges in the Condensed Consolidated Statements of Operations.

Restructuring liabilities are reported within other accrued liabilities in the Condensed Consolidated Balance Sheets. The following table provides a summary of changes in the restructuring liabilities for the Company's 2021 Restructuring Plan and prior year plan (in millions):


	December 31, 2020		Charges		Cash Payments		Other		June 30, 2021
Severance	$	50.7	$	13.8	$	(62.9)	$	1.0	$	2.6
Facility consolidations	—		6.9		(0.2)		(6.3)		0.4
Contract terminations and other	—		20.2		—		(5.3)		14.9
Total	$	50.7	$	40.9	$	(63.1)	$	(10.6)	$	17.9

Debt

6 Months Ended

Jun. 30, 2021

Debt Disclosure [Abstract]

Debt

Note 9. Debt

Debt

The following table summarizes the Company's total debt (in millions, except percentages):


				As of
	Maturity Date	Effective Interest Rates		June 30, 2021		December 31, 2020
Senior Notes ("Notes"):
4.500% fixed-rate notes ("2024 Notes")	March 2024	4.70	%	$	—	$	265.8
4.350% fixed-rate notes ("2025-I Notes")	June 2025	4.47	%	—		158.0
1.200% fixed-rate notes ("2025-II Notes")	December 2025	1.37	%	400.0		400.0
3.750% fixed-rate notes ("2029 Notes")	August 2029	3.86	%	500.0		500.0
2.000% fixed-rate notes ("2030 Notes")	December 2030	2.12	%	400.0		400.0
5.950% fixed-rate notes ("2041 Notes")	March 2041	6.03	%	400.0		400.0
Total Notes				1,700.0		2,123.8
Unaccreted discount and debt issuance costs				(13.6)		(16.8)
Hedge accounting fair value adjustments(*)				8.0		20.3
Total				$	1,694.4	$	2,127.3

________________________________

(*) Represents the fair value adjustments for interest rate swaps with an aggregate notional amount of $600.0 million. These interest rate swaps convert the fixed interest rates of certain Senior Notes to floating interest rates and are designated as fair value hedges. See Note 5, Derivative Instruments, for a discussion of the Company's interest rate swaps.

In January 2021, the Company redeemed the remaining $265.8 million of its outstanding 2024 Notes and the remaining $158.0 million of its outstanding 2025-I Notes, for a principal redemption amount in the aggregate of $482.1 million, plus accrued interest. The repayments resulted in a loss on extinguishment of debt of $60.6 million, consisting primarily of a premium on the early redemption and acceleration of unamortized debt discount and fees on the redeemed debt.

The Notes above are the Company’s senior unsecured and unsubordinated obligations, ranking equally in right of payment to all of the Company’s existing and future senior unsecured and unsubordinated indebtedness, and senior in right of payment to any of the Company’s future indebtedness that is expressly subordinated to the Notes.

Interest on the Notes is payable in cash semiannually. The effective interest rates for the Notes include the interest on the Notes, accretion of the discount, and amortization of issuance costs. The indenture and the supplemental indentures (together, the "indentures") that govern the Notes also contain various covenants, including limitations on the Company's ability to incur liens or enter into sale-leaseback transactions over certain dollar thresholds.

As of June 30, 2021, the Company was in compliance with all covenants in the indentures governing the Notes.

Revolving Credit Facility

The Company has an unsecured revolving credit facility that will expire in April 2024, which enables borrowings of up to $500.0 million, with an option to increase the amount of the credit facility by up to an additional $200.0 million, subject to the lenders' approval. The credit facility will terminate in April 2024. As of June 30, 2021, the Company was in compliance with all covenants and no amounts were outstanding under our credit facility.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (h)
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Publisher FASB
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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 1B
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

+ Details

Equity

6 Months Ended

Jun. 30, 2021

Stockholders' Equity Note [Abstract]

Equity

Note 10. Equity

The following table summarizes dividends paid and stock repurchases under the Company's stock repurchase program (in millions, except per share amounts):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Dividends:
Per share	$	0.20	$	0.20	$	0.40	$	0.40
Amount	$	64.7	$	66.3	$	129.9	$	131.8

Repurchased under the 2018 Stock Repurchase Program:
Shares	4.2		—		9.3		10.3
Average price per share(*)	$	26.34	$	—	$	25.30	$	23.83
Amount	$	110.0	$	—	$	235.0	$	200.0

________________________________

(*) $23.83 average price per share for the six months ended June 30, 2020 includes $200.0 million in open market purchases, and settlement of the forward contract of $40.0 million under the ASR, which was initiated during the fourth quarter of 2019.

Cash Dividends on Shares of Common Stock

During the three and six months ended June 30, 2021, the Company declared and paid a quarterly cash dividend of $0.20 per common share, totaling $64.7 million and $129.9 million, respectively, on its outstanding common stock. Any future dividends, and the establishment of record and payment dates, are subject to approval by the Board of Directors (the “Board”) of Juniper or an authorized committee thereof. See Note 16, Subsequent Events, for discussion of the Company's dividend declaration subsequent to June 30, 2021.

Stock Repurchase Activities

During the six months ended June 30, 2021, the Company repurchased 9.3 million shares of its common stock in the open market for an aggregate purchase price of $235.0 million at an average price of $25.30 per share, under the 2018 Stock Repurchase Program.

As of June 30, 2021, there was approximately $1.1 billion of authorized funds remaining under the 2018 Stock Repurchase Program.

Future share repurchases under the 2018 Stock Repurchase Program will be subject to a review of the circumstances at that time and will be made from time to time in private transactions or open market purchases as permitted by securities laws and other legal requirements.

In addition to repurchases under the 2018 Stock Repurchase Program, the Company also withholds shares of common stock from certain employees in connection with the vesting of stock awards issued to such employees to satisfy applicable tax withholding requirements. Such withheld shares are treated as common stock repurchases in the Company's financial statements as they reduce the number of shares that would have been issued upon vesting. Repurchases associated with tax withholdings were not material during the three and six months ended June 30, 2021 and June 30, 2020.

Accumulated Other Comprehensive Income, Net of Tax

The components of accumulated other comprehensive income, net of related taxes, for the six months ended June 30, 2021 were as follows (in millions):


	Unrealized Gains/Losses on Available-for- Sale Debt Securities		Unrealized Gains/Losses on Cash Flow Hedges		Foreign Currency Translation Adjustments		Total
Balance as of December 31, 2020	$	34.1	$	57.7	$	(36.2)	$	55.6
Other comprehensive income (loss) before reclassifications	0.1		18.8		(1.5)		17.4
Amount reclassified from accumulated other comprehensive income (loss)	(1.0)		(16.1)		—		(17.1)
Other comprehensive income (loss), net	(0.9)		2.7		(1.5)		0.3
Balance as of June 30, 2021	$	33.2	$	60.4	$	(37.7)	$	55.9

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Employee Benefit Plans

6 Months Ended

Jun. 30, 2021

Share-based Payment Arrangement [Abstract]

Employee Benefit Plans

Note 11. Employee Benefit Plans

Equity Incentive Plans

The Company has stock-based compensation plans pursuant to which it has granted stock options, restricted stock units (“RSUs”), and performance share awards (“PSAs”). The Company also maintains its 2008 Employee Stock Purchase Plan (the “ESPP”) for all eligible employees. As of June 30, 2021, 10.0 million and 10.1 million shares were available for future issuance under the Company's 2015 Equity Incentive Plan (the "2015 Plan") and the ESPP, respectively. In connection with past acquisitions, the Company has also assumed or substituted stock options, RSUs, restricted stock awards ("RSAs"), and PSAs.

RSU, RSA and PSA Activities

The Company’s RSU, RSA and PSA activity and related information as of and for the six months ended June 30, 2021 were as follows (in millions, except per share amounts and years):


	Outstanding RSUs, RSAs and PSAs
	Number of Shares	Weighted Average Grant-Date Fair Value per Share		Weighted Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
Balance as of December 31, 2020	19.9	$	23.05
Granted(*)	3.3	23.95
Awards assumed upon the acquisition of Apstra	2.2	25.49
Vested	(4.4)	24.47
Canceled	(1.4)	24.25
Balance as of June 30, 2021	19.6	$	23.08	1.4	$	536.1

________________________________

(*) Includes 1.3 million service-based, 1.5 million performance-based, and 0.5 million market-based RSUs and PSAs, as applicable. The number of shares subject to performance-based and market-based conditions represents the aggregate maximum number of shares that may be issued pursuant to the award over its full term. The grant date fair value of RSUs and PSAs was reduced by the present value of dividends expected to be paid on the underlying shares of common stock during the requisite and derived service period as these awards are not entitled to receive dividends until vested.

Employee Stock Purchase Plan

The following table summarizes employee stock purchases through the ESPP (in millions, except per share amounts):


	Six Months Ended June 30,
	2021		2020
Shares purchased	1.4		1.4
Average exercise price per share	$	19.75	$	19.50

Share-Based Compensation Expense

Share-based compensation expense associated with stock options, RSUs, RSAs, PSAs, and the ESPP purchase rights was recorded in the following cost and expense categories in the Condensed Consolidated Statements of Operations (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Cost of revenues - Product	$	1.0	$	1.1	$	2.3	$	2.5
Cost of revenues - Service	3.9		3.4		8.4		7.6
Research and development	20.1		19.0		44.3		34.2
Sales and marketing	14.9		13.2		31.4		27.0
General and administrative	10.6		7.3		21.6		14.7
Total	$	50.5	$	44.0	$	108.0	$	86.0

The following table summarizes share-based compensation expense by award type (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Stock options	$	2.5	$	1.8	$	5.2	$	3.7
RSUs, RSAs, and PSAs	44.6		37.3		94.5		72.2
ESPP	3.4		4.9		8.3		10.1
Total	$	50.5	$	44.0	$	108.0	$	86.0

As of June 30, 2021, the total unrecognized compensation cost related to unvested share-based awards was $303.7 million to be recognized over a weighted-average period of 1.89 years.

Segments

6 Months Ended

Jun. 30, 2021

Segment Reporting [Abstract]

Segments

Note 12. Segments

The Company operates in one reportable segment. The Company's chief executive officer, who is the chief operating decision maker, reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance, accompanied by disaggregated information about net revenues by customer solution, customer vertical, and geographic region as presented below.

Effective in the first quarter of fiscal 2021, the Company began reporting its revenue by customer solution in the following three categories: Automated WAN Solutions, Cloud-Ready Data Center, AI-Driven Enterprise. In addition, the Company began reporting Hardware Maintenance and Professional Services in the first quarter of fiscal 2021. The change provides for alignment on key growth drivers that is aligned with the Company's strategy.

The following table presents net revenues by customer solution (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Customer Solutions:
Automated WAN Solutions	$	396.1	$	406.8	$	782.5	$	722.3
Cloud-Ready Data Center	201.9		157.6		359.3		332.0
AI-Driven Enterprise	195.1		152.7		356.3		296.1
Hardware Maintenance and Professional Services	379.2		369.2		748.6		733.9
Total	$	1,172.3	$	1,086.3	$	2,246.7	$	2,084.3

The following table presents net revenues by customer vertical (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Cloud	$	320.6	$	285.5	$	591.3	$	547.4
Service Provider	443.7		436.2		881.9		811.7
Enterprise	408.0		364.6		773.5		725.2
Total	$	1,172.3	$	1,086.3	$	2,246.7	$	2,084.3

The Company attributes revenues to geographic region based on the customer’s shipping address. The following table presents net revenues by geographic region (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Americas:
United States	$	597.4	$	547.3	$	1,120.5	$	1,076.7
Other	55.3		61.5		115.2		111.6
Total Americas	652.7		608.8		1,235.7		1,188.3
Europe, Middle East, and Africa	323.9		294.1		635.0		549.1
Asia Pacific	195.7		183.4		376.0		346.9
Total	$	1,172.3	$	1,086.3	$	2,246.7	$	2,084.3

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

Income Taxes

6 Months Ended

Jun. 30, 2021

Income Tax Disclosure [Abstract]

Income Taxes

Note 13. Income Taxes

The following table provides details of income taxes (in millions, except percentages):


	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Income before income taxes	$	74.8		$	86.1		$	37.0		$	114.4
Income tax provision	$	12.8		$	24.9		$	6.1		$	32.8
Effective tax rate	17.1		%	28.9		%	16.5		%	28.7		%

The Company’s effective tax rate differs from the federal statutory rate of 21% primarily due to the tax impact of state taxes, geographic mix of earnings including foreign-derived intangible income deductions and global intangible low-taxed income, research and development ("R&D") tax credits, tax audit settlements, non-deductible compensation, cost sharing of stock-based compensation, and other transfer pricing adjustments.

The Company’s effective tax rate for the six months ended June 30, 2021 reflects the loss on extinguishment of debt of $60.6 million and other restructuring charges of $40.9 million in the period.

The Company's effective tax rate during the six months ended June 30, 2020 reflected the cumulative impact of cost sharing for

stock-based compensation of $18.2 million, partially offset by a reduction of income tax reserves of $15.2 million, which includes interest of $1.7 million.

As of June 30, 2021, the total amount of gross unrecognized tax benefits was $118.9 million.

The Company engages in continuous discussions and negotiations with tax authorities regarding tax matters in various jurisdictions. There is a greater than remote likelihood that the balance of the gross unrecognized tax benefits will decrease by up to $3.5 million within the next twelve months due to the completion of tax review cycles in various tax jurisdictions and lapses of applicable statutes of limitation.

The Company is currently under examination by the Internal Revenue Service and the India tax authorities for the 2017 through 2018 tax years and the 2017 tax year, respectively.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

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+ Details

Net Income per Share

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Net Income per Share

Note 14. Net Income per Share

The Company computed basic and diluted net (loss) income per share as follows (in millions, except per share amounts):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Numerator:
Net income	$	62.0	$	61.2	$	30.9	$	81.6
Denominator:
Weighted-average shares used to compute basic income per share	324.5		331.0		325.4		330.9
Dilutive effect of employee stock awards	5.9		2.1		6.1		3.8
Weighted-average shares used to compute diluted income per share	330.4		333.1		331.5		334.7
Net income per share:
Basic	$	0.19	$	0.18	$	0.09	$	0.25
Diluted	$	0.19	$	0.18	$	0.09	$	0.24

Anti-dilutive shares	0.6		7.6		1.8		6.1

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 15. Commitments and Contingencies Commitments Except for the items below, there have been no material changes to the Company's commitments compared to the commitments described in Note 15, Commitments and Contingencies, in Notes to Consolidated Financial Statements in Item 8 of Part II of the Form 10-K. Purchase Commitments with Contract Manufacturers and Suppliers In order to reduce manufacturing lead times and in the interest of having access to adequate component supply, the Company enters into agreements with contract manufacturers and certain suppliers to procure inventory based on the Company's requirements. A significant portion of the Company's purchase commitments arising from these agreements consists of firm and non-cancelable commitments. These purchase commitments totaled $1,795.0 million as of June 30, 2021. Legal Proceedings In the ordinary course of business, the Company is subject to various pending and potential investigations, disputes, litigations, and legal proceedings. The Company records an accrual for loss contingencies for legal proceedings when it believes that an unfavorable outcome is both (a) probable and (b) the amount or range of any possible loss is reasonably estimable. The Company intends to aggressively defend itself in any legal matters, and while the outcome of any pending matters is not currently determinable, the Company believes that none of its currently existing claims or proceedings are likely to have a material adverse effect on its financial position. Notwithstanding the foregoing, there are many uncertainties associated with any litigation and these matters or any other third-party claims against the Company may cause the Company to incur costly litigation and/or substantial settlement charges. In addition, the resolution of any intellectual property litigation may require the Company to make royalty payments, which could adversely affect gross margins in future periods. If any of these events were to occur, the Company's business, financial condition, results of operations, and cash flows could be adversely affected. The actual liability in any such matters may be materially different from the Company's estimates, if any, which could result in the need to adjust the liability and record additional expenses.

Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 16. Subsequent Events Dividend Declaration On July 27, 2021, the Company announced that the Board declared a cash dividend of $0.20 per share of common stock to be paid on September 22, 2021 to stockholders of record as of the close of business on September 1, 2021.

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The Condensed Consolidated Financial Statements of Juniper Networks, Inc. (the “Company” or “Juniper”) were prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information. Accordingly, they do not include all information and footnotes required by U.S. GAAP for complete financial statements. The Condensed Consolidated Balance Sheet as of December 31, 2020 has been derived from the audited Consolidated Financial Statements at that date. In the opinion of management, all adjustments, including normal recurring accruals, considered necessary for a fair presentation have been included. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021, or any future period. These Condensed Consolidated Financial Statements and accompanying notes should be read in conjunction with the audited Consolidated Financial Statements and accompanying notes in the Company's Annual Report on Form 10-K for the year ended December 31, 2020 (the "Form 10-K"). We have evaluated all subsequent events through the date these condensed consolidated financial statements were issued.
Use of Estimates	The preparation of the financial statements and related disclosures in accordance with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the amounts reported in the Condensed Consolidated Financial Statements and the accompanying notes. Actual results could differ materially from those estimates under different assumptions or conditions.
Recently Adopted Accounting Standards and Recent Accounting Standards Not Yet Adopted	Recently Adopted Accounting Standards Simplifying the Accounting for Income Taxes: On January 1, 2021, the Company adopted ASU No. 2019-12 (Topic 740) Income Taxes — Simplifying the Accounting for Income Taxes, which enhances and simplifies various aspects related to accounting for income taxes. Upon adoption, the standard did not have a material impact on the Condensed Consolidated Financial Statements. Recent Accounting Standards Not Yet Adopted Reference Rate Reform: In March 2020, the FASB issued ASU No. 2020-04 (Topic 848), Reference Rate Reform - Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides temporary optional expedients and exceptions to the existing guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative reference rates, such as the Secured Overnight Financing Rate. In January 2021, the FASB issued ASU No. 2021-01 (Topic 848), Reference Rate Reform: Scope, which refines the scope of Topic 848 and clarifies some of its guidance. The amendments were effective upon issuance and may be applied through December 31, 2022, to any new or amended contracts, hedging relationships, and other transactions that reference LIBOR. The Company is currently evaluating the impact of the transition and disclosure requirements of the standard on its Condensed Consolidated Financial Statements.

Business Combinations (Tables)

6 Months Ended

Jun. 30, 2021

Business Combinations [Abstract]

Schedule of Estimated Fair Value of Assets Acquired

The following table summarizes the preliminary fair value of the assets acquired and liabilities assumed at the acquisition date (in millions):


	Amount
Cash and cash equivalents	$	1.8
Goodwill	84.0
Intangible assets	87.8
Other assets acquired	12.6
Liabilities assumed	(6.8)
Total	$	179.4

Schedule of the Fair Value of Separately Identifiable Intangible Assets Acquired

The following table summarizes the fair value of the separately identifiable intangible assets at the time of acquisition (in millions):


	Amount
Intangible assets(*):
Developed technology	$	80.5
Customer relationships	7.3

Total intangible assets acquired	$	87.8

________________________________

(*) Estimated useful life assigned to Developed Technology and Customer Relationships is 5 and 1.5 years, respectively.

Cash Equivalents and Investments (Tables)

6 Months Ended

Jun. 30, 2021

Cash Equivalents and Investments [Abstract]

Schedule of unrealized gains and losses and fair value of available-for-sale debt securities

The following table summarizes the Company's unrealized gains and losses and fair value of investments designated as available-for-sale debt securities as of June 30, 2021 and December 31, 2020 (in millions):


	As of June 30, 2021								As of December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Fixed income securities:
Asset-backed securities	$	90.8	$	0.1	$	(0.1)	$	90.8	$	76.5	$	0.2	$	—	$	76.7
Certificates of deposit	15.3		—		—		15.3		32.9		—		—		32.9
Commercial paper	78.2		—		—		78.2		89.3		—		—		89.3
Corporate debt securities	482.8		2.8		(0.2)		485.4		632.0		5.5		(0.1)		637.4
Foreign government debt securities	7.6		—		—		7.6		4.6		—		—		4.6
Time deposits	64.2		—		—		64.2		255.6		—		—		255.6
U.S. government agency securities	26.6		0.1		—		26.7		65.3		0.2		—		65.5
U.S. government securities	146.6		0.4		—		147.0		232.8		1.0		—		233.8
Total fixed income securities	912.1		3.4		(0.3)		915.2		1,389.0		6.9		(0.1)		1,395.8
Privately-held debt and redeemable preferred stock securities	21.2		39.9		—		61.1		18.3		37.4		—		55.7
Total available-for-sale debt securities	$	933.3	$	43.3	$	(0.3)	$	976.3	$	1,407.3	$	44.3	$	(0.1)	$	1,451.5

Reported as:
Cash equivalents	$	93.7	$	—	$	—	$	93.7	$	333.7	$	—	$	—	$	333.7
Short-term investments	327.2		1.1		—		328.3		404.3		1.2		—		405.5
Long-term investments	491.2		2.3		(0.3)		493.2		651.0		5.7		(0.1)		656.6
Other long-term assets	21.2		39.9		—		61.1		18.3		37.4		—		55.7
Total	$	933.3	$	43.3	$	(0.3)	$	976.3	$	1,407.3	$	44.3	$	(0.1)	$	1,451.5

Maturities of fixed income securities

The following table presents the contractual maturities of the Company's total fixed income securities as of June 30, 2021 (in millions):


	Amortized Cost		Estimated Fair Value
Due in less than one year	$	420.9	$	422.0
Due between one and five years	491.2		493.2
Total	$	912.1	$	915.2

Schedule of investments in equity securities

The following table presents the Company's investments in equity securities as of June 30, 2021 and December 31, 2020 (in millions):


	As of
	June 30, 2021		December 31, 2020
Equity investments with readily determinable fair value:
Money market funds	$	387.1	$	536.6
Mutual funds	31.9		29.3
Publicly-traded equity securities	7.2		6.6
Equity investments without readily determinable fair value:	145.1		146.2
Total equity securities	$	571.3	$	718.7

Reported as:
Cash equivalents	$	370.3	$	519.8
Short-term investments	7.2		6.6
Prepaid expenses and other current assets	10.4		9.9
Other long-term assets	183.4		182.4
Total	$	571.3	$	718.7

Schedule of reconciliation of cash, cash equivalents and restricted cash

The following table provides a reconciliation of cash, cash equivalents, and restricted cash included in the Condensed Consolidated Balance Sheets as of June 30, 2021 and December 31, 2020 (in millions):


	As of
	June 30, 2021		December 31, 2020
Cash and cash equivalents	$	986.7	$	1,361.9
Restricted cash included in Prepaid expenses and other current assets	19.0		19.2
Restricted cash included in Other long-term assets	3.7		1.9
Total cash, cash equivalents, and restricted cash	$	1,009.4	$	1,383.0

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Assets and liabilities measured at fair value on a recurring basis

The following table provides a summary of assets and liabilities measured at fair value on a recurring basis and as reported in the Condensed Consolidated Balance Sheets as of June 30, 2021 and December 31, 2020 (in millions):


	Fair Value Measurements at June 30, 2021								Fair Value Measurements at December 31, 2020
	Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total
Assets:
Available-for-sale debt securities:
Asset-backed securities	$	—	$	90.8	$	—	$	90.8	$	—	$	76.7	$	—	$	76.7
Certificates of deposit	—		15.3		—		15.3		—		32.9		—		32.9
Commercial paper	—		78.2		—		78.2		—		89.3		—		89.3
Corporate debt securities	—		485.4		—		485.4		—		637.4		—		637.4
Foreign government debt securities	—		7.6		—		7.6		—		4.6		—		4.6
Time deposits	—		64.2		—		64.2		—		255.6		—		255.6
U.S. government agency securities	—		26.7		—		26.7		—		65.5		—		65.5
U.S. government securities	102.9		44.1		—		147.0		140.0		93.8		—		233.8
Privately-held debt and redeemable preferred stock securities	—		—		61.1		61.1		—		—		55.7		55.7
Total available-for-sale debt securities	102.9		812.3		61.1		976.3		140.0		1,255.8		55.7		1,451.5
Equity securities:
Money market funds	387.1		—		—		387.1		536.6		—		—		536.6
Mutual funds	31.9		—		—		31.9		29.3		—		—		29.3
Publicly-traded equity securities	7.2		—		—		7.2		6.6		—		—		6.6
Total equity securities	426.2		—		—		426.2		572.5		—		—		572.5
Derivative assets:
Foreign exchange contracts	—		29.2		—		29.2		—		38.0		—		38.0
Interest rate contracts	—		61.7		—		61.7		—		51.0		—		51.0
Total derivative assets	—		90.9		—		90.9		—		89.0		—		89.0
Total assets measured at fair value on a recurring basis	$	529.1	$	903.2	$	61.1	$	1,493.4	$	712.5	$	1,344.8	$	55.7	$	2,113.0
Liabilities:
Derivative liabilities:
Foreign exchange contracts	$	—	$	(5.9)	$	—	$	(5.9)	$	—	$	(0.5)	$	—	$	(0.5)
Total derivative liabilities	—		(5.9)		—		(5.9)		—		(0.5)		—		(0.5)
Total liabilities measured at fair value on a recurring basis	$	—	$	(5.9)	$	—	$	(5.9)	$	—	$	(0.5)	$	—	$	(0.5)


	Fair Value Measurements at June 30, 2021								Fair Value Measurements at December 31, 2020
	Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Remaining Inputs (Level 2)		Significant Other Unobservable Remaining Inputs (Level 3)		Total

Total assets, reported as:
Cash equivalents	$	370.3	$	93.7	$	—	$	464.0	$	519.8	$	333.7	$	—	$	853.5
Short-term investments	85.7		249.8		—		335.5		101.0		311.1		—		412.1
Long-term investments	24.4		468.8		—		493.2		45.6		611.0		—		656.6
Prepaid expenses and other current assets	10.5		22.5		—		33.0		9.9		28.0		—		37.9
Other long-term assets	38.2		68.4		61.1		167.7		36.2		61.0		55.7		152.9
Total assets measured at fair value	$	529.1	$	903.2	$	61.1	$	1,493.4	$	712.5	$	1,344.8	$	55.7	$	2,113.0

Total liabilities, reported as:
Other accrued liabilities	$	—	$	(2.9)	$	—	$	(2.9)	$	—	$	(0.3)	$	—	$	(0.3)
Other long-term liabilities	—		(3.0)		—		(3.0)		—		(0.2)		—		(0.2)
Total liabilities measured at fair value on a recurring basis	$	—	$	(5.9)	$	—	$	(5.9)	$	—	$	(0.5)	$	—	$	(0.5)

Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Derivative instruments

The notional amount of the Company's derivatives is summarized as follows (in millions):


	As of
	June 30, 2021		December 31, 2020
Designated derivatives:
Cash flow hedges:
Foreign currency contracts	$	811.0	$	722.1
Interest rate lock contracts	650.0		650.0
Fair value hedges:
Interest rate swap contracts	600.0		300.0
Total designated derivatives	2,061.0		1,672.1

Non-designated derivatives	125.3		174.1
Total	$	2,186.3	$	1,846.2

Schedule of Derivative Assets at Fair Value

The fair value of derivative instruments on the Condensed Consolidated Balance Sheets was as follows:


		As of
	Balance Sheet Classification	June 30, 2021		December 31, 2020
Derivative assets:
Derivatives designated as hedging instruments:
Foreign currency contracts	Other current assets	$	21.4	$	27.8
Foreign currency contracts	Other long-term assets	6.7		10.0
Interest rate lock contracts	Other long-term assets	53.7		30.7
Interest rate swap contracts	Other long-term assets	8.0		20.3
Total derivatives designated as hedging instruments		$	89.8	$	88.8
Derivatives not designated as hedging instruments	Other current assets	1.1		0.2
Total derivative assets		$	90.9	$	89.0
Derivative liabilities:
Derivatives designated as hedging instruments:
Foreign currency contracts	Other accrued liabilities	$	2.7	$	0.2
Foreign currency contracts	Other long-term liabilities	3.0		0.2


Total derivatives designated as hedging instruments		$	5.7	$	0.4
Derivatives not designated as hedging instruments	Other accrued liabilities	0.2		0.1
Total derivative liabilities		$	5.9	$	0.5

Schedule of Derivative Liabilities at Fair Value

The fair value of derivative instruments on the Condensed Consolidated Balance Sheets was as follows:


		As of
	Balance Sheet Classification	June 30, 2021		December 31, 2020
Derivative assets:
Derivatives designated as hedging instruments:
Foreign currency contracts	Other current assets	$	21.4	$	27.8
Foreign currency contracts	Other long-term assets	6.7		10.0
Interest rate lock contracts	Other long-term assets	53.7		30.7
Interest rate swap contracts	Other long-term assets	8.0		20.3
Total derivatives designated as hedging instruments		$	89.8	$	88.8
Derivatives not designated as hedging instruments	Other current assets	1.1		0.2
Total derivative assets		$	90.9	$	89.0
Derivative liabilities:
Derivatives designated as hedging instruments:
Foreign currency contracts	Other accrued liabilities	$	2.7	$	0.2
Foreign currency contracts	Other long-term liabilities	3.0		0.2


Total derivatives designated as hedging instruments		$	5.7	$	0.4
Derivatives not designated as hedging instruments	Other accrued liabilities	0.2		0.1
Total derivative liabilities		$	5.9	$	0.5

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Goodwill and Purchased Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The Company's goodwill activity during the six months ended June 30, 2021 was as follows (in millions):


	Total
December 31, 2020	$	3,669.6
Additions due to business combinations	84.5
June 30, 2021	$	3,754.1

Schedule of Acquired Indefinite-Lived Intangible Assets by Major Class

The Company’s purchased intangible assets, net, were as follows (in millions):


	As of June 30, 2021								As of December 31, 2020
	Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net		Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net
Finite-lived intangible assets:
Technologies and patents	$	903.8	$	(628.9)	$	(55.1)	$	219.8	$	823.5	$	(598.2)	$	(55.1)	$	170.2
Customer relationships	136.3		(91.3)		(2.8)		42.2		129.2		(84.4)		(2.8)		42.0
Trade names and other	9.6		(5.3)		—		4.3		9.6		(4.1)		—		5.5
Total	1,049.7		(725.5)		(57.9)		266.3		962.3		(686.7)		(57.9)		217.7
Indefinite-lived intangible assets:
In-process research and development	49.0		—		—		49.0		49.0		—		—		49.0
Total purchased intangible assets	$	1,098.7	$	(725.5)	$	(57.9)	$	315.3	$	1,011.3	$	(686.7)	$	(57.9)	$	266.7

Schedule of Acquired Finite-Lived Intangible Assets by Major Class

The Company’s purchased intangible assets, net, were as follows (in millions):


	As of June 30, 2021								As of December 31, 2020
	Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net		Gross		Accumulated Amortization		Accumulated Impairments and Other Charges		Net
Finite-lived intangible assets:
Technologies and patents	$	903.8	$	(628.9)	$	(55.1)	$	219.8	$	823.5	$	(598.2)	$	(55.1)	$	170.2
Customer relationships	136.3		(91.3)		(2.8)		42.2		129.2		(84.4)		(2.8)		42.0
Trade names and other	9.6		(5.3)		—		4.3		9.6		(4.1)		—		5.5
Total	1,049.7		(725.5)		(57.9)		266.3		962.3		(686.7)		(57.9)		217.7
Indefinite-lived intangible assets:
In-process research and development	49.0		—		—		49.0		49.0		—		—		49.0
Total purchased intangible assets	$	1,098.7	$	(725.5)	$	(57.9)	$	315.3	$	1,011.3	$	(686.7)	$	(57.9)	$	266.7

Estimated Future Amortization Expense of Purchased Intangible Assets with Finite Lives

As of June 30, 2021, the estimated future amortization expense of purchased intangible assets with finite lives is as follows (in millions):


Years Ending December 31,	Amount
Remainder of 2021	$	40.3
2022	72.8
2023	66.9
2024	47.4
2025	37.8
Thereafter	1.1
Total	$	266.3

Other Financial Information (Tables)

6 Months Ended

Jun. 30, 2021

Other Financial Information [Abstract]

Schedule of inventories

Total inventory consisted of the following (in millions):


	As of
	June 30, 2021		December 31, 2020
Production and service materials	$	167.5	$	158.1
Finished goods	54.8		63.8
Total inventory	$	222.3	$	221.9

Reported as:
Inventory	$	211.5	$	210.2
Other long-term assets	10.8		11.7
Total inventory	$	222.3	$	221.9

Schedule of warranties

Changes during the six months ended June 30, 2021 in the Company’s warranty reserve as reported within other accrued liabilities in the Condensed Consolidated Balance Sheets were as follows (in millions):


Balance as of December 31, 2020	$	30.2
Provisions made during the period	19.4

Actual costs incurred during the period	(18.8)

Balance as of June 30, 2021	$	30.8

Schedule of performance obligation

The following table summarizes the transaction price for contracts that have not yet been recognized as revenue as of June 30, 2021 and when the Company expects to recognize the amounts as revenue (in millions):


	Revenue Recognition Expected by Period
	Total		Less than 1 year		1-3 years		More than 3 years
Product	$	120.9	$	102.3	$	15.5	$	3.1
Service(*)	1,225.2		798.3		350.2		76.7
Total	$	1,346.1	$	900.6	$	365.7	$	79.8

________________________________

(*) Represents unearned service revenue allocated to the performance obligations not delivered or partially delivered as of June 30, 2021. The unearned service revenue is comprised of deferred revenue and non-cancellable contract revenue, which has not been invoiced yet.

Schedule of other income (expense), net

Other expense, net, consisted of the following (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Interest income	$	3.4	$	9.3	$	7.5	$	24.4
Interest expense	(12.6)		(19.3)		(26.3)		(39.5)
(Loss) gain on investments, net	(1.2)		6.5		2.6		0.7
Other	(0.5)		(0.9)		0.3		(1.1)
Other expense, net	$	(10.9)	$	(4.4)	$	(15.9)	$	(15.5)

Restructuring Charges (Tables)

6 Months Ended

Jun. 30, 2021

Restructuring and Related Activities [Abstract]

Schedule of restructuring liabilities

The following table provides a summary of changes in the restructuring liabilities for the Company's 2021 Restructuring Plan and prior year plan (in millions):


	December 31, 2020		Charges		Cash Payments		Other		June 30, 2021
Severance	$	50.7	$	13.8	$	(62.9)	$	1.0	$	2.6
Facility consolidations	—		6.9		(0.2)		(6.3)		0.4
Contract terminations and other	—		20.2		—		(5.3)		14.9
Total	$	50.7	$	40.9	$	(63.1)	$	(10.6)	$	17.9

Debt (Tables)

6 Months Ended

Jun. 30, 2021

Debt Disclosure [Abstract]

Schedule of total debt

The following table summarizes the Company's total debt (in millions, except percentages):


				As of
	Maturity Date	Effective Interest Rates		June 30, 2021		December 31, 2020
Senior Notes ("Notes"):
4.500% fixed-rate notes ("2024 Notes")	March 2024	4.70	%	$	—	$	265.8
4.350% fixed-rate notes ("2025-I Notes")	June 2025	4.47	%	—		158.0
1.200% fixed-rate notes ("2025-II Notes")	December 2025	1.37	%	400.0		400.0
3.750% fixed-rate notes ("2029 Notes")	August 2029	3.86	%	500.0		500.0
2.000% fixed-rate notes ("2030 Notes")	December 2030	2.12	%	400.0		400.0
5.950% fixed-rate notes ("2041 Notes")	March 2041	6.03	%	400.0		400.0
Total Notes				1,700.0		2,123.8
Unaccreted discount and debt issuance costs				(13.6)		(16.8)
Hedge accounting fair value adjustments(*)				8.0		20.3
Total				$	1,694.4	$	2,127.3

________________________________

(*) Represents the fair value adjustments for interest rate swaps with an aggregate notional amount of $600.0 million. These interest rate swaps convert the fixed interest rates of certain Senior Notes to floating interest rates and are designated as fair value hedges. See Note 5, Derivative Instruments, for a discussion of the Company's interest rate swaps.

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 835
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28541-108399

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 835
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Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495743-112612

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21521-112644

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21538-112644

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21475-112644

+ Details

Equity (Tables)

6 Months Ended

Jun. 30, 2021

Stockholders' Equity Note [Abstract]

Schedule of dividends paid and stock repurchases and retirements under stock repurchase program

The following table summarizes dividends paid and stock repurchases under the Company's stock repurchase program (in millions, except per share amounts):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Dividends:
Per share	$	0.20	$	0.20	$	0.40	$	0.40
Amount	$	64.7	$	66.3	$	129.9	$	131.8

Repurchased under the 2018 Stock Repurchase Program:
Shares	4.2		—		9.3		10.3
Average price per share(*)	$	26.34	$	—	$	25.30	$	23.83
Amount	$	110.0	$	—	$	235.0	$	200.0

________________________________

(*) $23.83 average price per share for the six months ended June 30, 2020 includes $200.0 million in open market purchases, and settlement of the forward contract of $40.0 million under the ASR, which was initiated during the fourth quarter of 2019.

Schedule of accumulated other comprehensive loss, net of taxes

The components of accumulated other comprehensive income, net of related taxes, for the six months ended June 30, 2021 were as follows (in millions):


	Unrealized Gains/Losses on Available-for- Sale Debt Securities		Unrealized Gains/Losses on Cash Flow Hedges		Foreign Currency Translation Adjustments		Total
Balance as of December 31, 2020	$	34.1	$	57.7	$	(36.2)	$	55.6
Other comprehensive income (loss) before reclassifications	0.1		18.8		(1.5)		17.4
Amount reclassified from accumulated other comprehensive income (loss)	(1.0)		(16.1)		—		(17.1)
Other comprehensive income (loss), net	(0.9)		2.7		(1.5)		0.3
Balance as of June 30, 2021	$	33.2	$	60.4	$	(37.7)	$	55.9

Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2021

Share-based Payment Arrangement [Abstract]

Schedule of nonvested share activity

The Company’s RSU, RSA and PSA activity and related information as of and for the six months ended June 30, 2021 were as follows (in millions, except per share amounts and years):


	Outstanding RSUs, RSAs and PSAs
	Number of Shares	Weighted Average Grant-Date Fair Value per Share		Weighted Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
Balance as of December 31, 2020	19.9	$	23.05
Granted(*)	3.3	23.95
Awards assumed upon the acquisition of Apstra	2.2	25.49
Vested	(4.4)	24.47
Canceled	(1.4)	24.25
Balance as of June 30, 2021	19.6	$	23.08	1.4	$	536.1

________________________________

(*) Includes 1.3 million service-based, 1.5 million performance-based, and 0.5 million market-based RSUs and PSAs, as applicable. The number of shares subject to performance-based and market-based conditions represents the aggregate maximum number of shares that may be issued pursuant to the award over its full term. The grant date fair value of RSUs and PSAs was reduced by the present value of dividends expected to be paid on the underlying shares of common stock during the requisite and derived service period as these awards are not entitled to receive dividends until vested.

Schedule of employee stock purchases through ESPP

The following table summarizes employee stock purchases through the ESPP (in millions, except per share amounts):


	Six Months Ended June 30,
	2021		2020
Shares purchased	1.4		1.4
Average exercise price per share	$	19.75	$	19.50

Schedule of employee service share-based compensation, allocation of recognized period costs

Share-based compensation expense associated with stock options, RSUs, RSAs, PSAs, and the ESPP purchase rights was recorded in the following cost and expense categories in the Condensed Consolidated Statements of Operations (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Cost of revenues - Product	$	1.0	$	1.1	$	2.3	$	2.5
Cost of revenues - Service	3.9		3.4		8.4		7.6
Research and development	20.1		19.0		44.3		34.2
Sales and marketing	14.9		13.2		31.4		27.0
General and administrative	10.6		7.3		21.6		14.7
Total	$	50.5	$	44.0	$	108.0	$	86.0

Disclosure of share-based compensation arrangements by share-based payment award

The following table summarizes share-based compensation expense by award type (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Stock options	$	2.5	$	1.8	$	5.2	$	3.7
RSUs, RSAs, and PSAs	44.6		37.3		94.5		72.2
ESPP	3.4		4.9		8.3		10.1
Total	$	50.5	$	44.0	$	108.0	$	86.0

Segments (Tables)

6 Months Ended

Jun. 30, 2021

Segment Reporting [Abstract]

Schedule of financial information for each segment

The following table presents net revenues by customer solution (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Customer Solutions:
Automated WAN Solutions	$	396.1	$	406.8	$	782.5	$	722.3
Cloud-Ready Data Center	201.9		157.6		359.3		332.0
AI-Driven Enterprise	195.1		152.7		356.3		296.1
Hardware Maintenance and Professional Services	379.2		369.2		748.6		733.9
Total	$	1,172.3	$	1,086.3	$	2,246.7	$	2,084.3

The following table presents net revenues by customer vertical (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Cloud	$	320.6	$	285.5	$	591.3	$	547.4
Service Provider	443.7		436.2		881.9		811.7
Enterprise	408.0		364.6		773.5		725.2
Total	$	1,172.3	$	1,086.3	$	2,246.7	$	2,084.3

Schedule of net revenues by geographic region

The Company attributes revenues to geographic region based on the customer’s shipping address. The following table presents net revenues by geographic region (in millions):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Americas:
United States	$	597.4	$	547.3	$	1,120.5	$	1,076.7
Other	55.3		61.5		115.2		111.6
Total Americas	652.7		608.8		1,235.7		1,188.3
Europe, Middle East, and Africa	323.9		294.1		635.0		549.1
Asia Pacific	195.7		183.4		376.0		346.9
Total	$	1,172.3	$	1,086.3	$	2,246.7	$	2,084.3

Income Taxes (Tables)

6 Months Ended

Jun. 30, 2021

Income Tax Disclosure [Abstract]

Schedule of effective income tax rate reconciliation

The following table provides details of income taxes (in millions, except percentages):


	Three Months Ended June 30,						Six Months Ended June 30,
	2021			2020			2021			2020
Income before income taxes	$	74.8		$	86.1		$	37.0		$	114.4
Income tax provision	$	12.8		$	24.9		$	6.1		$	32.8
Effective tax rate	17.1		%	28.9		%	16.5		%	28.7		%

Net Income per Share (Tables)

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Schedule of basic and diluted net income per share

The Company computed basic and diluted net (loss) income per share as follows (in millions, except per share amounts):


	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Numerator:
Net income	$	62.0	$	61.2	$	30.9	$	81.6
Denominator:
Weighted-average shares used to compute basic income per share	324.5		331.0		325.4		330.9
Dilutive effect of employee stock awards	5.9		2.1		6.1		3.8
Weighted-average shares used to compute diluted income per share	330.4		333.1		331.5		334.7
Net income per share:
Basic	$	0.19	$	0.18	$	0.09	$	0.25
Diluted	$	0.19	$	0.18	$	0.09	$	0.24

Anti-dilutive shares	0.6		7.6		1.8		6.1

Business Combinations - Additional Information (Details) - Apstra $ in Millions	Jan. 27, 2021 USD ($)
Business Acquisition [Line Items]
Percentage of voting interest acquired	100.00%
Consideration transferred	$ 179.4
Consideration transferred, cash	176.7
Consideration transferred, share-based awards	$ 2.7

Business Combinations - Estimated Fair Value of Assets Acquired (Details) - USD ($) $ in Millions	Jun. 30, 2021	Jan. 27, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill	$ 3,754.1		$ 3,669.6
Apstra
Business Acquisition [Line Items]
Cash and cash equivalents		$ 1.8
Goodwill		84.0
Intangible assets		87.8
Other assets acquired		12.6
Liabilities assumed		(6.8)
Total		$ 179.4

Business Combinations - Fair Value of Identifiable Intangible Assets Acquired (Details) - Apstra $ in Millions	Jan. 27, 2021 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 87.8
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 80.5
Estimated useful life	5 years
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 7.3
Estimated useful life	1 year 6 months

Cash Equivalents and Investments - Available-For-Sale (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Available-for-sale debt securities:
Amortized Cost	$ 933.3	$ 1,407.3
Gross Unrealized Gains	43.3	44.3
Gross Unrealized Losses	(0.3)	(0.1)
Estimated Fair Value	976.3	1,451.5
Cash equivalents
Available-for-sale debt securities:
Amortized Cost	93.7	333.7
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	93.7	333.7
Short-term investments
Available-for-sale debt securities:
Amortized Cost	327.2	404.3
Gross Unrealized Gains	1.1	1.2
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	328.3	405.5
Long-term investments
Available-for-sale debt securities:
Amortized Cost	491.2	651.0
Gross Unrealized Gains	2.3	5.7
Gross Unrealized Losses	(0.3)	(0.1)
Estimated Fair Value	493.2	656.6
Other long-term assets
Available-for-sale debt securities:
Amortized Cost	21.2	18.3
Gross Unrealized Gains	39.9	37.4
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	61.1	55.7
Asset-backed securities
Available-for-sale debt securities:
Amortized Cost	90.8	76.5
Gross Unrealized Gains	0.1	0.2
Gross Unrealized Losses	(0.1)	0.0
Estimated Fair Value	90.8	76.7
Certificates of deposit
Available-for-sale debt securities:
Amortized Cost	15.3	32.9
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	15.3	32.9
Commercial paper
Available-for-sale debt securities:
Amortized Cost	78.2	89.3
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	78.2	89.3
Corporate debt securities
Available-for-sale debt securities:
Amortized Cost	482.8	632.0
Gross Unrealized Gains	2.8	5.5
Gross Unrealized Losses	(0.2)	(0.1)
Estimated Fair Value	485.4	637.4
Foreign government debt securities
Available-for-sale debt securities:
Amortized Cost	7.6	4.6
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	7.6	4.6
Time deposits
Available-for-sale debt securities:
Amortized Cost	64.2	255.6
Gross Unrealized Gains	0.0	0.0
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	64.2	255.6
U.S. government agency securities
Available-for-sale debt securities:
Amortized Cost	26.6	65.3
Gross Unrealized Gains	0.1	0.2
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	26.7	65.5
U.S. government securities
Available-for-sale debt securities:
Amortized Cost	146.6	232.8
Gross Unrealized Gains	0.4	1.0
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	147.0	233.8
Fixed Income Securities
Available-for-sale debt securities:
Amortized Cost	912.1	1,389.0
Gross Unrealized Gains	3.4	6.9
Gross Unrealized Losses	(0.3)	(0.1)
Estimated Fair Value	915.2	1,395.8
Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Amortized Cost	21.2	18.3
Gross Unrealized Gains	39.9	37.4
Gross Unrealized Losses	0.0	0.0
Estimated Fair Value	$ 61.1	$ 55.7

Cash Equivalents and Investments - Maturities of Fixed Income Securities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Amortized Cost
Amortized Cost	$ 933.3	$ 1,407.3
Estimated Fair Value
Total	976.3	1,451.5
Fixed Income Securities
Amortized Cost
Due in less than one year	420.9
Due between one and five years	491.2
Amortized Cost	912.1	1,389.0
Estimated Fair Value
Due in less than one year	422.0
Due between one and five years	493.2
Total	$ 915.2	$ 1,395.8

Cash Equivalents and Investments - Narrative (Details)	3 Months Ended		6 Months Ended
Cash Equivalents and Investments - Narrative (Details)	Jun. 30, 2021 USD ($) investment	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) investment	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Restricted Cash and Cash Equivalents Items [Line Items]
Gross unrealized losses	$ 300,000		$ 300,000		$ 100,000
Total investments in unrealized loss position \| investment	147		147
Available-for-sale debt securities, gross realized gain	$ 0	$ 0	$ 0	$ 0
Available-for-sale debt securities, gross realized loss	0	0	0	0
Equity investments, unrealized gains	0	0	0	0
Equity investments, unrealized losses	0	0	0	0
Restricted cash and investments	71,300,000		71,300,000
Prepaid expenses and other current assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and investments	29,400,000		29,400,000
Other long-term assets
Restricted Cash and Cash Equivalents Items [Line Items]
Gross unrealized losses	0		0		$ 0
Restricted cash and investments	41,900,000		41,900,000
Debt Securities
Restricted Cash and Cash Equivalents Items [Line Items]
Allowance for credit losses	$ 0	$ 0	$ 0	$ 0

Cash Equivalents and Investments - Investments in Equity Securities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments without readily determinable fair value:	$ 145.1	$ 146.2
Total equity securities	571.3	718.7
Cash equivalents
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	370.3	519.8
Short-term investments
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	7.2	6.6
Prepaid expenses and other current assets
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	10.4	9.9
Other long-term assets
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	183.4	182.4
Money market funds
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments with readily determinable fair value:	387.1	536.6
Mutual funds
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments with readily determinable fair value:	31.9	29.3
Publicly-traded equity securities
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments with readily determinable fair value:	$ 7.2	$ 6.6

Cash Equivalents and Investments - Restricted Cash and Investments (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 986.7	$ 1,361.9
Total cash, cash equivalents, and restricted cash	1,009.4	1,383.0	$ 1,521.2	$ 1,276.5
Prepaid expenses and other current assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in Prepaid expenses and other current assets	19.0	19.2
Other long-term assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in Prepaid expenses and other current assets	$ 3.7	$ 1.9

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Available-for-sale debt securities:
Available-for-sale debt securities	$ 976.3	$ 1,451.5
Derivative assets:
Derivative assets:	90.9	89.0
Cash equivalents
Available-for-sale debt securities:
Available-for-sale debt securities	93.7	333.7
Short-term investments
Available-for-sale debt securities:
Available-for-sale debt securities	328.3	405.5
Long-term investments
Available-for-sale debt securities:
Available-for-sale debt securities	493.2	656.6
Asset-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	90.8	76.7
Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	15.3	32.9
Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	78.2	89.3
Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	485.4	637.4
Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	7.6	4.6
Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	64.2	255.6
U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	26.7	65.5
U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	147.0	233.8
Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	61.1	55.7
Money market funds
Equity securities:
Equity securities	387.1	536.6
Publicly-traded equity securities
Equity securities:
Equity securities	7.2	6.6
Fair Value, Measurements, Recurring
Available-for-sale debt securities:
Available-for-sale debt securities	976.3	1,451.5
Equity securities:
Equity securities	426.2	572.5
Derivative assets:
Derivative assets:	90.9	89.0
Total assets measured at fair value on a recurring basis	1,493.4	2,113.0
Liabilities:
Derivative liabilities:	(5.9)	(0.5)
Total liabilities measured at fair value on a recurring basis	(5.9)	(0.5)
Fair Value, Measurements, Recurring \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	464.0	853.5
Fair Value, Measurements, Recurring \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	335.5	412.1
Fair Value, Measurements, Recurring \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	493.2	656.6
Fair Value, Measurements, Recurring \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	33.0	37.9
Fair Value, Measurements, Recurring \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	167.7	152.9
Fair Value, Measurements, Recurring \| Other accrued liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	(2.9)	(0.3)
Fair Value, Measurements, Recurring \| Other long-term liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	(3.0)	(0.2)
Fair Value, Measurements, Recurring \| Foreign exchange contracts
Derivative assets:
Derivative assets:	29.2	38.0
Liabilities:
Derivative liabilities:	(5.9)	(0.5)
Fair Value, Measurements, Recurring \| Interest rate contracts
Derivative assets:
Derivative assets:	61.7	51.0
Fair Value, Measurements, Recurring \| Asset-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	90.8	76.7
Fair Value, Measurements, Recurring \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	15.3	32.9
Fair Value, Measurements, Recurring \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	78.2	89.3
Fair Value, Measurements, Recurring \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	485.4	637.4
Fair Value, Measurements, Recurring \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	7.6	4.6
Fair Value, Measurements, Recurring \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	64.2	255.6
Fair Value, Measurements, Recurring \| U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	26.7	65.5
Fair Value, Measurements, Recurring \| U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	147.0	233.8
Fair Value, Measurements, Recurring \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	61.1	55.7
Fair Value, Measurements, Recurring \| Money market funds
Equity securities:
Equity securities	387.1	536.6
Fair Value, Measurements, Recurring \| Mutual funds
Equity securities:
Equity securities	31.9	29.3
Fair Value, Measurements, Recurring \| Publicly-traded equity securities
Equity securities:
Equity securities	7.2	6.6
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1)
Available-for-sale debt securities:
Available-for-sale debt securities	102.9	140.0
Equity securities:
Equity securities	426.2	572.5
Derivative assets:
Derivative assets:	0.0	0.0
Total assets measured at fair value on a recurring basis	529.1	712.5
Liabilities:
Derivative liabilities:	0.0	0.0
Total liabilities measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	370.3	519.8
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	85.7	101.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	24.4	45.6
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	10.5	9.9
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	38.2	36.2
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Other accrued liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Other long-term liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Foreign exchange contracts
Derivative assets:
Derivative assets:	0.0	0.0
Liabilities:
Derivative liabilities:	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Interest rate contracts
Derivative assets:
Derivative assets:	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Asset-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	102.9	140.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Money market funds
Equity securities:
Equity securities	387.1	536.6
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Mutual funds
Equity securities:
Equity securities	31.9	29.3
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets For Identical Assets (Level 1) \| Publicly-traded equity securities
Equity securities:
Equity securities	7.2	6.6
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2)
Available-for-sale debt securities:
Available-for-sale debt securities	812.3	1,255.8
Equity securities:
Equity securities	0.0	0.0
Derivative assets:
Derivative assets:	90.9	89.0
Total assets measured at fair value on a recurring basis	903.2	1,344.8
Liabilities:
Derivative liabilities:	(5.9)	(0.5)
Total liabilities measured at fair value on a recurring basis	(5.9)	(0.5)
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	93.7	333.7
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	249.8	311.1
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	468.8	611.0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	22.5	28.0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	68.4	61.0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Other accrued liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	(2.9)	(0.3)
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Other long-term liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	(3.0)	(0.2)
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Foreign exchange contracts
Derivative assets:
Derivative assets:	29.2	38.0
Liabilities:
Derivative liabilities:	(5.9)	(0.5)
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Interest rate contracts
Derivative assets:
Derivative assets:	61.7	51.0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Asset-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	90.8	76.7
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	15.3	32.9
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	78.2	89.3
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	485.4	637.4
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	7.6	4.6
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	64.2	255.6
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	26.7	65.5
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	44.1	93.8
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Money market funds
Equity securities:
Equity securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Mutual funds
Equity securities:
Equity securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2) \| Publicly-traded equity securities
Equity securities:
Equity securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3)
Available-for-sale debt securities:
Available-for-sale debt securities	61.1	55.7
Equity securities:
Equity securities	0.0	0.0
Derivative assets:
Derivative assets:	0.0	0.0
Total assets measured at fair value on a recurring basis	61.1	55.7
Liabilities:
Derivative liabilities:	0.0	0.0
Total liabilities measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	61.1	55.7
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Other accrued liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Other long-term liabilities
Liabilities:
Total liabilities measured at fair value on a recurring basis	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Foreign exchange contracts
Derivative assets:
Derivative assets:	0.0	0.0
Liabilities:
Derivative liabilities:	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Interest rate contracts
Derivative assets:
Derivative assets:	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Asset-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	61.1	55.7
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Money market funds
Equity securities:
Equity securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Mutual funds
Equity securities:
Equity securities	0.0	0.0
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3) \| Publicly-traded equity securities
Equity securities:
Equity securities	$ 0.0	$ 0.0

Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
Fair Value Measurements - Narrative (Details) - USD ($)	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities without readily determinable fair value, upward adjustment		$ 0
Equity securities without readily determinable fair value, downward adjustment		0
Goodwill and intangible impairment		0
Contract manufacturer deposit (non-interest bearing)	$ 66,400,000	66,400,000
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	5,900,000	5,900,000	$ 500,000
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	0	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	0	0	0
Significant Other Observable Remaining Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total outstanding debt, fair value	1,873,400,000	1,873,400,000	2,386,600,000
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	5,900,000	5,900,000	$ 500,000
Privately-held debt and redeemable preferred stock securities \| Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain (loss) on investments	$ 0	$ 0

Derivative Instruments - Notional Amount (Details) - USD ($)	Jun. 30, 2021	Apr. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Notional amount of derivatives	$ 2,186,300,000		$ 1,846,200,000
Designated derivatives:
Derivative [Line Items]
Notional amount of derivatives	2,061,000,000.0		1,672,100,000
Non-designated derivatives
Derivative [Line Items]
Notional amount of derivatives	125,300,000		174,100,000
Foreign currency contracts \| Cash flow hedges: \| Designated derivatives:
Derivative [Line Items]
Notional amount of derivatives	811,000,000.0		722,100,000
Interest rate lock contracts \| Cash flow hedges: \| Designated derivatives:
Derivative [Line Items]
Notional amount of derivatives	650,000,000.0	$ 300,000,000.0	650,000,000.0
Interest rate swap contracts \| Fair value hedges: \| Designated derivatives:
Derivative [Line Items]
Notional amount of derivatives	$ 600,000,000.0		$ 300,000,000.0

Derivative Instruments - Fair Value of Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Derivative assets:	$ 90.9	$ 89.0
Derivative liabilities:	5.9	0.5
Designated derivatives:
Derivative [Line Items]
Derivative assets:	89.8	88.8
Derivative liabilities:	5.7	0.4
Designated derivatives: \| Other current assets \| Foreign exchange contracts
Derivative [Line Items]
Derivative assets:	21.4	27.8
Designated derivatives: \| Other long-term assets \| Foreign exchange contracts
Derivative [Line Items]
Derivative assets:	6.7	10.0
Designated derivatives: \| Other long-term assets \| Interest rate lock contracts
Derivative [Line Items]
Derivative assets:	53.7	30.7
Designated derivatives: \| Other long-term assets \| Interest rate swap contracts
Derivative [Line Items]
Derivative assets:	8.0	20.3
Designated derivatives: \| Other accrued liabilities \| Foreign exchange contracts
Derivative [Line Items]
Derivative liabilities:	2.7	0.2
Designated derivatives: \| Other long-term liabilities \| Foreign exchange contracts
Derivative [Line Items]
Derivative liabilities:	3.0	0.2
Non-designated derivatives \| Other current assets
Derivative [Line Items]
Derivative assets:	1.1	0.2
Non-designated derivatives \| Other accrued liabilities
Derivative [Line Items]
Derivative liabilities:	$ 0.2	$ 0.1

Derivative Instruments - Narrative (Details) - USD ($)		3 Months Ended		6 Months Ended		12 Months Ended
Derivative Instruments - Narrative (Details) - USD ($)	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Apr. 30, 2021
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	$ 2,186,300,000	$ 2,186,300,000		$ 2,186,300,000		$ 1,846,200,000
Foreign exchange contracts
Derivatives, Notional Amount [Line Items]
Foreign currency forward contracts, amounts reclassified out of AOCI		8,100,000	$ (6,900,000)	$ 18,100,000	$ (8,300,000)
Foreign exchange contracts \| Minimum
Derivatives, Notional Amount [Line Items]
Maturity of foreign currency derivatives				1 month
Foreign exchange contracts \| Maximum
Derivatives, Notional Amount [Line Items]
Maturity of foreign currency derivatives				4 months
Designated derivatives:
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	2,061,000,000.0	2,061,000,000.0		$ 2,061,000,000.0		1,672,100,000
Cash flow hedges:
Derivatives, Notional Amount [Line Items]
Derivative instruments, gain (loss) recognized in other comprehensive income (loss), effective portion		(26,900,000)	$ 17,900,000	$ 26,100,000	$ (11,200,000)
Cash flow hedges: \| Designated derivatives:
Derivatives, Notional Amount [Line Items]
Maximum maturities of cash flow hedge derivatives				36 months
Losses expected to be reclassified into earnings within the next 12 months	18,700,000
Cash flow hedges: \| Designated derivatives: \| Interest rate lock contracts
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	650,000,000.0	650,000,000.0		$ 650,000,000.0		$ 650,000,000.0	$ 300,000,000.0
Swaps designated as cash flow hedges, expected termination period						5 years
Derivative, Expiration Period				10 years
Cash flow hedges: \| Designated derivatives: \| Foreign exchange contracts
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	$ 811,000,000.0	$ 811,000,000.0		$ 811,000,000.0		$ 722,100,000

Goodwill and Purchased Intangible Assets - Goodwill Rollforward (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Goodwill [Roll Forward]
Goodwill, beginning balance			$ 3,669,600,000
Additions due to business combinations	$ 84,500,000
Goodwill, end of period	3,754,100,000		3,754,100,000
Goodwill impairment	$ 0	$ 0	$ 0	$ 0

Goodwill and Purchased Intangible Assets - Purchased Intangible Assets, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Purchased Intangible Assets [Line Items]
Gross	$ 1,049.7		$ 1,049.7		$ 962.3
Accumulated Amortization	(725.5)		(725.5)		(686.7)
Accumulated Impairments and Other Charges	(57.9)		(57.9)		(57.9)
Net	266.3		266.3		217.7
Total purchased intangible assets	1,098.7		1,098.7		1,011.3
Net	315.3		315.3		266.7
Amortization of intangible assets	19.8	$ 9.4	38.8	$ 19.3
Impairment of intangible assets	0.0	$ 0.0	0.0	$ 0.0
In-process research and development
Purchased Intangible Assets [Line Items]
Indefinite-lived intangible assets:	49.0		49.0		49.0
Technologies and patents
Purchased Intangible Assets [Line Items]
Gross	903.8		903.8		823.5
Accumulated Amortization	(628.9)		(628.9)		(598.2)
Accumulated Impairments and Other Charges	(55.1)		(55.1)		(55.1)
Net	219.8		219.8		170.2
Customer relationships
Purchased Intangible Assets [Line Items]
Gross	136.3		136.3		129.2
Accumulated Amortization	(91.3)		(91.3)		(84.4)
Accumulated Impairments and Other Charges	(2.8)		(2.8)		(2.8)
Net	42.2		42.2		42.0
Trade names and other
Purchased Intangible Assets [Line Items]
Gross	9.6		9.6		9.6
Accumulated Amortization	(5.3)		(5.3)		(4.1)
Accumulated Impairments and Other Charges	0.0		0.0		0.0
Net	$ 4.3		$ 4.3		$ 5.5

Goodwill and Purchased Intangible Assets - Estimated Future Amortization Expense Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Amount
Remainder of 2021	$ 40.3
2022	72.8
2023	66.9
2024	47.4
2025	37.8
Thereafter	1.1
Net	$ 266.3	$ 217.7

Other Financial Information - Inventories, Net (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Schedule Of Inventory [Line Items]
Production and service materials	$ 167.5	$ 158.1
Finished goods	54.8	63.8
Total inventory	222.3	221.9
Inventory
Schedule Of Inventory [Line Items]
Total inventory	211.5	210.2
Other long-term assets
Schedule Of Inventory [Line Items]
Total inventory	$ 10.8	$ 11.7

Other Financial Information - Narrative (Details)	3 Months Ended	6 Months Ended
Other Financial Information - Narrative (Details)	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)
Other Financial Information [Abstract]
Contract manufacturer deposit (non-interest bearing)	$ 66,400,000	$ 66,400,000
Non-interest bearing deposit to contract manufacturer, unamortized discount	4,700,000	$ 4,700,000
Non-interest bearing deposit to contract manufacturer, imputed interest rate		5.10%
Disaggregation of Revenue [Line Items]
Deferred commission	30,600,000	$ 30,600,000
Amortization of deferred commission	42,500,000	82,900,000
Impairment loss	0	0
Product
Disaggregation of Revenue [Line Items]
Contract with customer, liability, revenue recognized	14,200,000	42,900,000
Service
Disaggregation of Revenue [Line Items]
Contract with customer, liability, revenue recognized	$ 212,500,000	$ 490,200,000

Other Financial Information - Warranties (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($)
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance as of December 31, 2020	$ 30.2
Provisions made during the period	19.4
Actual costs incurred during the period	(18.8)
Balance as of June 30, 2021	$ 30.8

Other Financial Information - Revenue (Details) $ in Millions	Jun. 30, 2021 USD ($)
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 1,346.1
Product
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	120.9
Service
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	1,225.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	900.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 \| Product
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 102.3
Revenue recognition expected by period, satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 \| Service
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 798.3
Revenue recognition expected by period, satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 365.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 \| Product
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 15.5
Revenue recognition expected by period, satisfaction period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 \| Service
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 350.2
Revenue recognition expected by period, satisfaction period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-07-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 79.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-07-01 \| Product
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 3.1
Revenue recognition expected by period, satisfaction period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-07-01 \| Service
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 76.7
Revenue recognition expected by period, satisfaction period

Other Financial Information - Revenue - Total (Details) $ in Millions	Jun. 30, 2021 USD ($)
Segment Reporting Information [Line Items]
Revenue recognition expected by period	$ 1,346.1
Product
Segment Reporting Information [Line Items]
Revenue recognition expected by period	120.9
Service
Segment Reporting Information [Line Items]
Revenue recognition expected by period	$ 1,225.2

Other Financial Information - Other Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other Financial Information [Abstract]
Interest income	$ 3.4	$ 9.3	$ 7.5	$ 24.4
Interest expense	(12.6)	(19.3)	(26.3)	(39.5)
(Loss) gain on investments, net	(1.2)	6.5	2.6	0.7
Other	(0.5)	(0.9)	0.3	(1.1)
Other expense, net	$ (10.9)	$ (4.4)	$ (15.9)	$ (15.5)

Restructuring Charges - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring charges (benefits)	$ 21.6	$ 4.8	$ 40.9	$ 13.7
2020 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges (benefits)			40.9
2020 Restructuring Plan \| Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges (benefits)	(0.9)		13.8
2020 Restructuring Plan \| Facility consolidations
Restructuring Cost and Reserve [Line Items]
Restructuring charges (benefits)	2.3		6.9
2020 Restructuring Plan \| Contract terminations and other
Restructuring Cost and Reserve [Line Items]
Restructuring charges (benefits)	20.2		$ 20.2
2020 Restructuring Plan \| Restructuring impairment charge
Restructuring Cost and Reserve [Line Items]
Restructuring charges (benefits)	$ 5.3

Restructuring Charges - Changes to Restructuring Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Reserve [Roll Forward]
Charges	$ 21.6	$ 4.8	$ 40.9	$ 13.7
2020 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance			50.7
Charges			40.9
Cash Payments			(63.1)
Other			(10.6)
Restructuring liability, ending balance	17.9		17.9
2020 Restructuring Plan \| Severance
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance			50.7
Charges	(0.9)		13.8
Cash Payments			(62.9)
Other			1.0
Restructuring liability, ending balance	2.6		2.6
2020 Restructuring Plan \| Facility consolidations
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance			0.0
Charges	2.3		6.9
Cash Payments			(0.2)
Other			(6.3)
Restructuring liability, ending balance	0.4		0.4
2020 Restructuring Plan \| Contract terminations and other
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance			0.0
Charges	20.2		20.2
Cash Payments			0.0
Other			(5.3)
Restructuring liability, ending balance	$ 14.9		$ 14.9

Debt - Schedule of Debt (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt	$ 1,700,000,000.0	$ 2,123,800,000
Unaccreted discount and debt issuance costs	(13,600,000)	(16,800,000)
Hedge accounting fair value adjustments	8,000,000.0	20,300,000
Total	1,694,400,000	2,127,300,000
Notional amount of derivatives	2,186,300,000	1,846,200,000
Designated derivatives:
Debt Instrument [Line Items]
Notional amount of derivatives	2,061,000,000.0	1,672,100,000
Designated derivatives: \| Fair value hedges: \| Interest rate swap contracts
Debt Instrument [Line Items]
Notional amount of derivatives	600,000,000.0	300,000,000.0
Senior notes \| 4.500% fixed-rate notes (2024 Notes)
Debt Instrument [Line Items]
Long-term debt	$ 0	265,800,000
Stated interest rate	4.50%
Effective interest rate	4.70%
Senior notes \| 4.350% fixed-rate notes ("2025-I Notes")
Debt Instrument [Line Items]
Long-term debt	$ 0	158,000,000.0
Stated interest rate	4.35%
Effective interest rate	4.47%
Senior notes \| 1.200% fixed-rate notes ("2025-II Notes")
Debt Instrument [Line Items]
Long-term debt	$ 400,000,000.0	400,000,000.0
Stated interest rate	1.20%
Effective interest rate	1.37%
Senior notes \| 3.750% fixed-rate notes ("2029 Notes")
Debt Instrument [Line Items]
Long-term debt	$ 500,000,000.0	500,000,000.0
Stated interest rate	3.75%
Effective interest rate	3.86%
Senior notes \| 2.000% fixed-rate notes ("2030 Notes")
Debt Instrument [Line Items]
Long-term debt	$ 400,000,000.0	400,000,000.0
Stated interest rate	2.00%
Effective interest rate	2.12%
Senior notes \| 5.950% fixed-rate notes ("2041 Notes")
Debt Instrument [Line Items]
Long-term debt	$ 400,000,000.0	$ 400,000,000.0
Stated interest rate	5.95%
Effective interest rate	6.03%

Debt - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
Debt - Narrative (Details) - USD ($) $ in Millions	Jan. 31, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ 0.0	$ 0.0	$ 60.6	$ 0.0
Senior notes
Debt Instrument [Line Items]
Principal redemption amount	$ 482.1
Loss on extinguishment of debt	60.6
Senior notes \| 4.500% fixed-rate notes (2024 Notes)
Debt Instrument [Line Items]
Principal redemption amount	265.8
Senior notes \| 4.350% fixed-rate notes ("2025-I Notes")
Debt Instrument [Line Items]
Principal redemption amount	$ 158.0

Debt - Revolving Credit Facility (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Amount outstanding	$ 1,694,400,000	$ 2,127,300,000
Unsecured Revolving Credit Facility \| Line of Credit
Line of Credit Facility [Line Items]
Borrowing capacity	500,000,000.0
Increase amount of borrowings, subject to lenders' approval	200,000,000.0
Amount outstanding	$ 0

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References + Details

Equity - Summary of Dividends Paid and Stock Repurchases and Retirements (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Dividends:
Per share (in dollars per share)	$ 0.20	$ 0.20	$ 0.40	$ 0.40
Amount	$ 64.7	$ 66.3	$ 129.9	$ 131.8
Repurchased under the 2018 Stock Repurchase Program:
Amount	$ 111.2	$ 2.1	$ 243.1	245.3
Forward contract under ASR				$ 40.0
Stock Repurchase Program 2018
Repurchased under the 2018 Stock Repurchase Program:
Shares (in shares)	4.2	0.0	9.3	10.3
Average price (in dollars per share)	$ 26.34	$ 0	$ 25.30	$ 23.83
Amount	$ 110.0	$ 0.0	$ 235.0	$ 200.0

Equity - Cash Dividends on Shares of Common Stock (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Stockholders' Equity Note [Abstract]
Cash dividends declared per share of common stock (in dollars per share)	$ 0.20		$ 0.20
Amount	$ 64.7	$ 66.3	$ 129.9	$ 131.8

Equity - Stock Repurchase Activities (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accelerated Share Repurchases [Line Items]
Common stock received, aggregate price	$ 111.2	$ 2.1	$ 243.1	$ 245.3
Stock Repurchase Program 2018
Accelerated Share Repurchases [Line Items]
Stock repurchased (in shares)			9.3
Common stock received, aggregate price	110.0	$ 0.0	$ 235.0	$ 200.0
Common stock repurchased, average cost per share (in dollars per share)			$ 25.30
Stock repurchase program, remaining authorized repurchase amount	$ 1,100.0		$ 1,100.0

Equity - Components of Accumulated Other Comprehensive (Loss) Income, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	$ 4,429.6	$ 4,390.7	$ 4,543.5	$ 4,610.6
Other comprehensive income (loss) before reclassifications			17.4
Amount reclassified from accumulated other comprehensive income (loss)			(17.1)
Other comprehensive income (loss), net	(25.4)	36.3	0.3	(4.4)
Balance	4,340.9	4,464.3	4,340.9	4,464.3
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	81.3	(59.2)	55.6	(18.5)
Other comprehensive income (loss), net	(25.4)	36.3	0.3	(4.4)
Balance	55.9	$ (22.9)	55.9	$ (22.9)
Unrealized Gains/Losses on Available-for- Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance			34.1
Other comprehensive income (loss) before reclassifications			0.1
Amount reclassified from accumulated other comprehensive income (loss)			(1.0)
Other comprehensive income (loss), net			(0.9)
Balance	33.2		33.2
Unrealized Gains/Losses on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance			57.7
Other comprehensive income (loss) before reclassifications			18.8
Amount reclassified from accumulated other comprehensive income (loss)			(16.1)
Other comprehensive income (loss), net			2.7
Balance	60.4		60.4
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance			(36.2)
Other comprehensive income (loss) before reclassifications			(1.5)
Amount reclassified from accumulated other comprehensive income (loss)			0.0
Other comprehensive income (loss), net			(1.5)
Balance	$ (37.7)		$ (37.7)

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=122038336&loc=d3e74512-122707

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-Subparagraph (SX 210.5-02(31))
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SX 210.5-02(29))
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Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
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-Subparagraph (f)
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Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Employee Benefit Plans - Equity Incentive Plan (Details) shares in Millions	Jun. 30, 2021 shares
Equity incentive plan 2015
Share-Based Compensation Plans
Number of shares available for future issuance (in shares)	10.0
Employee stock purchase plan 2008
Share-Based Compensation Plans
Number of shares available for future issuance (in shares)	10.1

Employee Benefit Plans - Restricted Stock Unit and Performance Share Award Activities (Details) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($) $ / shares shares
Number of Shares
Awards assumed upon the acquisition of Apstra (in shares)	2.2
Weighted Average Grant-Date Fair Value per Share
Awards assumed upon the acquisition of Apstra (in dollars per share) \| $ / shares	$ 25.49
RSUs, RSAs, and PSAs
Number of Shares
Balance at beginning of period (in shares)	19.9
Granted (in shares)	3.3
Vested (in shares)	(4.4)
Canceled (in shares)	(1.4)
Balance at end of period (in shares)	19.6
Weighted Average Grant-Date Fair Value per Share
Balance at beginning of period (in dollars per share) \| $ / shares	$ 23.05
Granted (in dollars per share) \| $ / shares	23.95
Vested (in dollars per share) \| $ / shares	24.47
Canceled (in dollars per share) \| $ / shares	24.25
Balance at end of period (in dollars per share) \| $ / shares	$ 23.08
Weighted Average Remaining Contractual Term (In Years)	1 year 4 months 24 days
Aggregate Intrinsic Value \| $	$ 536.1
Service-based RSUs
Number of Shares
Granted (in shares)	1.3
Performance Shares
Number of Shares
Granted (in shares)	1.5
Market-based RSUs
Number of Shares
Granted (in shares)	0.5

Employee Benefit Plans - Employee Stock Purchase Plan (Details) - Employee stock purchase plan 2008 - $ / shares shares in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares purchased (in shares)	1.4	1.4
Average exercise price per share (in dollars per share)	$ 19.75	$ 19.50

Employee Benefit Plans - Share Based Compensation by Cost and Expense Categories (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 50.5	$ 44.0	$ 108.0	$ 86.0
Stock options
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	2.5	1.8	5.2	3.7
RSUs, RSAs, and PSAs
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	44.6	37.3	94.5	72.2
ESPP
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	3.4	4.9	8.3	10.1
Cost of revenues - Product
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	1.0	1.1	2.3	2.5
Cost of revenues - Service
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	3.9	3.4	8.4	7.6
Research and development
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	20.1	19.0	44.3	34.2
Sales and marketing
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	14.9	13.2	31.4	27.0
General and administrative
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 10.6	$ 7.3	$ 21.6	$ 14.7

Employee Benefit Plans - Share Based Compensation by Share Based Payment Award Types (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($)
Share-based Payment Arrangement [Abstract]
Unrecognized compensation cost	$ 303.7
Unrecognized compensation, weighted average recognition period	1 year 10 months 20 days

Segments - Revenue by Product (Details) $ in Millions	3 Months Ended		6 Months Ended
Segments - Revenue by Product (Details) $ in Millions	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			1
Total net revenues	$ 1,172.3	$ 1,086.3	$ 2,246.7	$ 2,084.3
Automated WAN Solutions
Segment Reporting Information [Line Items]
Total net revenues	396.1	406.8	782.5	722.3
Cloud-Ready Data Center
Segment Reporting Information [Line Items]
Total net revenues	201.9	157.6	359.3	332.0
AI-Driven Enterprise
Segment Reporting Information [Line Items]
Total net revenues	195.1	152.7	356.3	296.1
Hardware Maintenance and Professional Services
Segment Reporting Information [Line Items]
Total net revenues	$ 379.2	$ 369.2	$ 748.6	$ 733.9

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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+ Details

Segments - Revenues by Customer Vertical (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Total net revenues	$ 1,172.3	$ 1,086.3	$ 2,246.7	$ 2,084.3
Cloud
Segment Reporting Information [Line Items]
Total net revenues	320.6	285.5	591.3	547.4
Service Provider
Segment Reporting Information [Line Items]
Total net revenues	443.7	436.2	881.9	811.7
Enterprise
Segment Reporting Information [Line Items]
Total net revenues	$ 408.0	$ 364.6	$ 773.5	$ 725.2

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Segments - Geographic (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Segments - Geographic (Details) - USD ($) $ in Millions	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Total net revenues	$ 1,172.3	$ 1,086.3	$ 2,246.7	$ 2,084.3
United States
Segment Reporting Information [Line Items]
Total net revenues	597.4	547.3	1,120.5	1,076.7
Other
Segment Reporting Information [Line Items]
Total net revenues	55.3	61.5	115.2	111.6
Total Americas
Segment Reporting Information [Line Items]
Total net revenues	652.7	608.8	1,235.7	1,188.3
Europe, Middle East, and Africa
Segment Reporting Information [Line Items]
Total net revenues	323.9	294.1	635.0	549.1
Asia Pacific
Segment Reporting Information [Line Items]
Total net revenues	$ 195.7	$ 183.4	$ 376.0	$ 346.9

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Contingency [Line Items]
Income before income taxes	$ 74.8	$ 86.1	$ 37.0	$ 114.4
Income tax provision	$ 12.8	$ 24.9	$ 6.1	$ 32.8
Effective tax rate	17.10%	28.90%	16.50%	28.70%
Loss on extinguishment of debt	$ 0.0	$ 0.0	$ 60.6	$ 0.0
Restructuring charges (benefits)	21.6	$ 4.8	40.9	13.7
Unrecognized tax benefits	118.9		118.9
Cost sharing for stock-based compensation				18.2
Reduction of income tax reserves				15.2
Interest				$ 1.7
Maximum
Income Tax Contingency [Line Items]
Unrecognized tax benefits, maximum decrease in the next twelve months	$ 3.5		$ 3.5

Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income	$ 62.0	$ 61.2	$ 30.9	$ 81.6
Denominator:
Basic (in shares)	324.5	331.0	325.4	330.9
Dilutive effect of employee stock awards (in shares)	5.9	2.1	6.1	3.8
Weighted-average shares used to compute diluted income per share (in shares)	330.4	333.1	331.5	334.7
Net income per share:
Basic (in dollars per share)	$ 0.19	$ 0.18	$ 0.09	$ 0.25
Diluted, (in dollars per share)	$ 0.19	$ 0.18	$ 0.09	$ 0.24
Anti-dilutive shares (in shares)	0.6	7.6	1.8	6.1

Commitments and Contingencies - Commitments (Details) $ in Millions	Jun. 30, 2021 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Purchase obligation	$ 1,795.0

Subsequent Events (Details) - $ / shares			3 Months Ended		6 Months Ended
Subsequent Events (Details) - $ / shares	Sep. 22, 2021	Jul. 27, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Subsequent Event [Line Items]
Cash dividends declared per share of common stock (in dollars per share)			$ 0.20		$ 0.20
Cash dividends (in dollars per share)			$ 0.20	$ 0.20	$ 0.40	$ 0.40
Forecast
Subsequent Event [Line Items]
Cash dividends declared per share of common stock (in dollars per share)		$ 0.20
Subsequent Event
Subsequent Event [Line Items]
Cash dividends (in dollars per share)	$ 0.20