Juniper Networks (JNPR) 10-K11 Feb 222021 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($)	12 Months Ended
Cover Page - USD ($)	Dec. 31, 2021	Feb. 09, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 8,749,000,000
Entity Common Stock, Shares Outstanding		322,758,505
Documents Incorporated by Reference	As noted herein, the information called for by Part III is incorporated by reference to specified portions of the registrant's definitive proxy statement to be filed in conjunction with the registrant's 2022 Annual Meeting of Stockholders, which is expected to be filed not later than 120 days after the registrant's fiscal year ended December 31, 2021.
Entity Central Index Key	0001043604
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY

Audit Information

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2021
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	San Jose, California
Auditor Firm ID	42

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net revenues:
Net revenues	$ 4,735.4	$ 4,445.1	$ 4,445.4
Cost of revenues:
Cost of revenues	1,995.3	1,871.4	1,828.6
Gross margin	2,740.1	2,573.7	2,616.8
Operating expenses:
Research and development	1,007.2	958.4	955.7
Sales and marketing	1,052.7	938.8	939.3
General and administrative	249.8	255.4	244.3
Restructuring charges	42.9	68	35.3
Total operating expenses	2,352.6	2,220.6	2,174.6
Operating income	387.5	353.1	442.2
Loss on extinguishment of debt	(60.6)	(55)	(15.3)
Other expense, net	(16.8)	(32.9)	(12.5)
Income before income taxes	310.1	265.2	414.4
Income tax provision	57.4	7.4	69.4
Net income	$ 252.7	$ 257.8	$ 345
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ 0.78	$ 0.78	$ 1.01
Diluted (in dollars per share)	$ 0.76	$ 0.77	$ 0.99
Shares used in computing net income per share:
Basic (in shares)	324.4	330.4	343.2
Diluted (in shares)	331.6	335.2	348.2
Product
Net revenues:
Net revenues	$ 3,078.1	$ 2,845	$ 2,867.7
Cost of revenues:
Cost of revenues	1,409.4	1,278.6	1,227
Service
Net revenues:
Net revenues	1,657.3	1,600.1	1,577.7
Cost of revenues:
Cost of revenues	$ 585.9	$ 592.8	$ 601.6

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 252.7	$ 257.8	$ 345
Available-for-sale debt securities:
Change in net unrealized gains and losses	(5)	5.7	4.6
Net realized gains reclassified into net income	(1.2)	(1.3)	(0.4)
Net change on available-for-sale debt securities	(6.2)	4.4	4.2
Cash flow hedges:
Change in net unrealized gains and losses	(13.5)	54.4	(8.9)
Net realized (gains) and losses reclassified into net income	(25.2)	7.6	5.5
Net change on cash flow hedges	(38.7)	62	(3.4)
Change in foreign currency translation adjustments	(12.8)	7.7	(1.1)
Other comprehensive (loss) income, net	(57.7)	74.1	(0.3)
Comprehensive income	$ 195	$ 331.9	$ 344.7

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents		$ 922.5	$ 1,361.9
Short-term investments		315.5	412.1
Accounts receivable, net of allowance for doubtful accounts of $6.7 and $9.9 as of December 31, 2021 and 2020, respectively		994.4	964.1
Inventory	[1]	272.6	210.2
Prepaid expenses and other current assets	[1]	451.6	322.9
Total current assets		2,956.6	3,271.2
Property and equipment, net		703	762.3
Operating lease assets		161.3	184.6
Long-term investments		455.5	656.6
Purchased intangible assets, net		284.3	266.7
Goodwill		3,762.1	3,669.6
Other long-term assets		564.2	567.3
Total assets		8,887	9,378.3
Current liabilities:
Accounts payable		273.7	277
Accrued compensation		336	270.7
Deferred revenue		937.9	867.3
Short-term debt		0	421.5
Other accrued liabilities		328.9	324.6
Total current liabilities		1,876.5	2,161.1
Long-term debt		1,686.8	1,705.8
Long-term deferred revenue		475.7	418.5
Long-term income taxes payable		330.5	312.5
Long-term operating lease liabilities		142.2	163.5
Other long-term liabilities		58.4	73.4
Total liabilities		4,570.1	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; 321.6 shares and 327.7 shares issued and outstanding as of December 31, 2021 and 2020, respectively		0	0
Additional paid-in capital		6,972.6	7,156.9
Accumulated other comprehensive (loss) income		(2.1)	55.6
Accumulated deficit		(2,653.6)	(2,669)
Total stockholders' equity		4,316.9	4,543.5
Total liabilities and stockholders' equity		$ 8,887	$ 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.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable, current	$ 6.7	$ 9.9
Convertible preferred stock - par value (in dollars per share)	$ 0.00001	$ 0.00001
Convertible preferred stock - shares authorized (in shares)	10,000,000	10,000,000
Convertible preferred stock - issued (in shares)	0	0
Convertible 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	1,000,000,000
Common stock - shares issued (in shares)	321,600,000	327,700,000
Common stock - outstanding (in shares)	321,600,000	327,700,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 252.7	$ 257.8	$ 345
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense	222.6	190.2	202.2
Depreciation, amortization, and accretion	237.4	212.4	210.3
Operating lease assets expense	44.9	42.3	42
Loss on extinguishment of debt	60.6	55	15.3
Deferred income taxes	71.7	(52.3)	2.9
Other	(1.1)	(2.9)	3.5
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable, net	(31.8)	(76.1)	(118.1)
Prepaid expenses and other assets	(310)	(117.8)	(100.7)
Accounts payable	0.2	56	6.4
Accrued compensation	70.3	38.7	6.5
Income taxes payable	24.3	(57.2)	(40.5)
Other accrued liabilities	(80.8)	4.4	(46.8)
Deferred revenue	128.7	61.5	0.9
Net cash provided by operating activities	689.7	612	528.9
Cash flows from investing activities:
Purchases of property and equipment	(100)	(100.4)	(109.6)
Purchases of available-for-sale debt securities	(649.8)	(967)	(3,209.8)
Proceeds from sales of available-for-sale debt securities	546.1	360.4	1,520
Proceeds from maturities and redemptions of available-for-sale debt securities	394	865	1,642.3
Purchases of equity securities	(10.1)	(17.4)	(107.1)
Proceeds from sales of equity securities	25.6	9.7	14.2
Proceeds from Pulse note receivable	0	50	0
Payments for business acquisitions, net of cash and cash equivalents acquired	(182.6)	(438.1)	(270.9)
Subsequent payments related to acquisitions in prior years	(10.1)	(45.9)	(7.3)
Other	0.7	(5.2)	0
Net cash provided by (used in) investing activities	13.8	(288.9)	(528.2)
Cash flows from financing activities:
Repurchase and retirement of common stock	(443.5)	(381.1)	(554.9)
Proceeds from issuance of common stock	56.4	54.7	55.6
Payment of dividends	(259.1)	(264.1)	(260.1)
Payment of debt	(423.8)	(376.2)	(950)
Issuance of debt, net	0	792.4	495.2
Payment for debt extinguishment costs	(58.3)	(52.9)	(14.6)
Other	(3.4)	4.8	0
Net cash used in financing activities	(1,131.7)	(222.4)	(1,228.8)
Effect of foreign currency exchange rates on cash, cash equivalents, and restricted cash	(12.1)	5.8	(1.2)
Net (decrease) increase in cash, cash equivalents, and restricted cash	(440.3)	106.5	(1,229.3)
Cash, cash equivalents, and restricted cash at beginning of period	1,383	1,276.5	2,505.8
Cash, cash equivalents, and restricted cash at end of period	942.7	1,383	1,276.5
Supplemental disclosures of cash flow information:
Cash paid for interest, net of amounts capitalized	62.6	87.2	90.6
Cash paid for income taxes, net	$ 113.2	$ 84.1	$ 98.8

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Shares	Common Stock and Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Accumulated DeficitCumulative Effect, Period of Adoption, Adjustment
Balance (shares) at Dec. 31, 2018			346.4
Balance at Dec. 31, 2018	$ 4,823.2			$ 7,672.8	$ (18.2)	$ (2,831.4)
Balance (Accounting Standards Update 2017-12) at Dec. 31, 2018		$ 0.1					$ 0.1
Balance (Accounting Standards Update 2016-02) at Dec. 31, 2018		$ (4.8)					$ (4.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	345					345
Other comprehensive loss, net	(0.3)				(0.3)
Issuance of common stock (in shares)			9.8
Issuance of common stock	55.6			55.6
Common stock assumed upon business combination	4.6			4.6
Repurchase and retirement of common stock (in shares)			(20.3)
Repurchase and retirement of common stock	(514.9)			(264.6)		(250.3)
Purchase of forward contract under accelerated share repurchase program ("ASR")	(40)			(40)
Share-based compensation expense	202.2			202.2
Payment of cash dividends	(260.1)			(260.1)
Balance (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]
Payments of cash dividends (in dollars per share)	$ 0.76
Net income	$ 257.8					257.8
Other comprehensive loss, net	74.1				74.1
Issuance of common stock (in shares)			10
Issuance of common stock	54.7			54.7
Common stock assumed upon business combination	1.5			1.5
Repurchase and retirement of common stock (in shares)			(18.2)
Repurchase and retirement of common stock	(421.1)			(235.7)		(185.4)
Purchase of forward contract under accelerated share repurchase program ("ASR")	40			40
Share-based compensation expense	190			190
Payment of cash dividends	(264.1)			(264.1)
Balance (shares) at Dec. 31, 2020			327.7
Balance at Dec. 31, 2020	$ 4,543.5			7,156.9	55.6	(2,669)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payments of cash dividends (in dollars per share)	$ 0.80
Net income	$ 252.7					252.7
Other comprehensive loss, net	(57.7)				(57.7)
Issuance of common stock (in shares)			9.9
Issuance of common stock	56.4			56.4
Common stock assumed upon business combination	2.7			2.7
Repurchase and retirement of common stock (in shares)			(16)
Repurchase and retirement of common stock	(443.5)			(206.2)		(237.3)
Share-based compensation expense	221.9			221.9
Payment of cash dividends	(259.1)			(259.1)
Balance (shares) at Dec. 31, 2021			321.6
Balance at Dec. 31, 2021	$ 4,316.9			$ 6,972.6	$ (2.1)	$ (2,653.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payments of cash dividends (in dollars per share)	$ 0.80

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - $ / shares	Oct. 26, 2021	Jul. 27, 2021	Apr. 27, 2021	Jan. 28, 2021	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Stockholders' Equity [Abstract]
Payments of cash dividends (in dollars per share)	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.80	$ 0.80	$ 0.76

Description of Business, Basis

Description of Business, Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Description of Business, Basis of Presentation and Significant Accounting Policies	Note 1. Description of Business, Basis of Presentation and Significant Accounting Policies Description of Business Juniper Networks, Inc. (the “Company” or “Juniper”) designs, develops, and sells products and services for high-performance networks, to enable customers to build scalable, reliable, secure and cost-effective networks for their businesses, while achieving agility and improved operating efficiency through automation. Juniper challenges the inherent complexity that comes with networking in the multicloud era. Juniper does this with products, solutions and services that transform the way people connect, work and live. Juniper simplifies the process of transitioning to a secure and automated multicloud environment to enable secure, AI-driven networks that connect the world. Basis of Presentation The Consolidated Financial Statements, which include the Company and its wholly-owned subsidiaries, are prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). All intercompany balances and transactions have been eliminated. Certain reclassifications have been made to the amounts for the prior year in order to conform to the current year's presentation. 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 Consolidated Financial Statements and the accompanying notes. The Company bases its estimates and assumptions on current facts, historical experience, and various other factors that it believes are reasonable under the circumstances, to determine the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from these estimates. Cash, Cash Equivalents, and Investments Cash and Cash Equivalents Cash and cash equivalents consist of cash on hand, demand deposits with banks, highly liquid investments in money market funds, commercial paper, government securities, certificates of deposits, time deposits, and corporate debt securities, which are readily convertible into cash. All highly liquid investments with original maturities of three months or less from Juniper's purchase date are classified as cash equivalents. Investments in Available-for-Sale Debt Securities The Company's investments in debt securities are classified as available-for-sale and include the Company's fixed income securities and investments in privately-held companies, consisting of debt and redeemable preferred stock securities. Fixed income securities primarily consist of corporate debt securities, U.S. treasury securities, time deposits, asset-backed and mortgage-backed securities, certificate of deposits, commercial paper, U.S. government agency securities, and foreign government debt securities. Fixed income securities are initially recorded at cost and periodically adjusted to fair value in the Consolidated Balance Sheets. The Company periodically evaluates these investments to determine if impairment charges are required. The Company determines whether a credit loss exists for available-for-sale debt securities in an unrealized loss position. When the fair value of a security is below its amortized cost, the amortized cost will be reduced to its fair value and the resulting loss will be recorded in Consolidated Statements of Operations, if it is more likely than not that we are required to sell the impaired security before recovery of its amortized cost basis, or we have the intention to sell the security. If neither of these conditions are met, the Company considers the extent to which the fair value is less than the amortized cost, any changes to the rating of the security by a rating agency, and review of the issuer's financial statements. If factors indicate a credit loss exists, an allowance for credit loss is recorded through other expense, net, limited by the amount that the fair value is less than the amortized cost basis. The Company's privately-held debt and redeemable preferred stock securities are included in other long-term assets in the Consolidated Balance Sheets and are recorded at fair value. Fair value is reassessed when the Company is made aware of information indicating a change in the enterprise value of the investee, including known acquisition offers, subsequent funding rounds, and investee's plans for liquidation. The Company periodically evaluates these securities for indicators of impairment, including the inability to recover a portion of or the entire carrying amount of the investment, the inability of the investee to sustain earnings, the reduction in or termination of financial commitment to the investee from other investors, the intention to sell the investment, and whether it is more likely than not that the Company will be required to sell the investment before recovery of the entire amortized cost basis. If the Company determines that the decline in an investment's value indicates credit losses, the difference is recognized as an impairment loss in its Consolidated Statements of Operations. For all available-for-sale debt securities, unrealized gains and the amount of unrealized loss relating to factors other than credit loss are reported as a separate component of accumulated other comprehensive loss in the Consolidated Balance Sheets. Realized gains and losses are determined based on the specific identification method and are reported in the Consolidated Statements of Operations. Investments in Equity Securities The Company's investments in equity securities with readily determinable fair values consist of money market funds, amounts under the non-qualified compensation plan ("NQDC") that are invested in mutual funds, and investments in public companies. These investments are measured at fair value with changes in fair value recognized in the Consolidated Statements of Operations. Equity securities without readily determinable fair values include the Company's investments in privately-held companies consisting of non-redeemable preferred stock and common stock securities. The Company accounts for these securities at cost, adjusted for changes from observable transactions for identical or similar investments of the same issuer, less impairments. Fair value of these equity securities is reassessed when the Company identifies observable price changes indicating that an adjustment upward or downward to the carrying value is necessary. Any observable changes in fair value are recognized in earnings as of the date that the observable transaction took place, rather than the current reporting date. In addition, the Company periodically evaluates equity securities without readily determinable fair values to determine if impairment charges are required by evaluating whether an event or change in circumstance has occurred that may have a significant adverse effect on the fair value of the investment. A qualitative assessment is performed each reporting period to assess whether there are any impairment indicators, including, but not limited to, significant deterioration in the investee's earnings performance; credit rating; asset quality or business prospects; adverse change in the regulatory, economic, or technological environment; change in the general market condition of the geographic area or industry; acquisition offers; and the ability to continue as a going concern. If such indicators are present, the Company estimates the fair value of impaired investments and recognizes an impairment loss in the Consolidated Statement of Operations equal to the difference between the carrying value and fair value. Fair Value Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which it transacts, and considers assumptions that market participants would use when pricing the asset or liability. The Company applies the following fair value hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1 – Quoted prices in active markets for identical assets or liabilities. Level 2 – Quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. These inputs are valued using market-based approaches. Level 3 – Inputs are unobservable inputs based on the Company’s assumptions. These inputs, if any, are valued using internal financial models. Derivative Instruments The Company uses derivative instruments, primarily foreign currency forward and interest rate contracts, to hedge certain foreign currency and interest rate exposures. The Company does not enter into derivatives for speculative or trading purposes. The Company uses foreign currency forward contracts to hedge certain forecasted foreign currency transactions relating to operating expenses. These derivatives are designated as cash flow hedges, which are carried at fair value with the derivative's gain or loss initially reported as a component of accumulated other comprehensive loss, and upon occurrence of the forecasted transaction, is subsequently reclassified into the costs of services or operating expense line item to which the hedged transaction relates. Cash flows from such hedges are classified as operating activities. The Company also uses foreign currency forward contracts to mitigate variability in gains and losses generated from the re-measurement of certain monetary assets and liabilities denominated in non-functional currencies. These derivatives are carried at fair value with changes recorded in other expense, net in the Consolidated Statements of Operations in the same period as the changes in the fair value from the re-measurement of the underlying assets and liabilities. Cash flows from such derivatives are classified as operating activities. The Company uses interest rate swaps to convert certain of our fixed interest rate notes to floating interest rates based on the London InterBank Offered Rate (LIBOR). All interest rate swaps will expire within nine years. The change in fair value of the derivative instrument substantially offsets the change in the fair value of the hedged item. These derivatives are classified in the Consolidated Statements of Cash Flows in the same section as the underlying item. The Company uses interest rate locks, which fix the benchmark interest rates of future debt issuance. The Company records changes in fair value of interest rate locks in accumulated other comprehensive income (loss) in the consolidated balance sheets, in the period of change. When the forecasted transaction occurs, the Company will start to amortize the accumulated gains or losses included as a component of other comprehensive income (loss) related to the interest rate lock cash flow hedges to interest expense. In the event the underlying forecasted transaction does not occur, or it becomes probable that it will not occur, the gains or losses on the related cash flow hedge from accumulated other comprehensive income (loss) will be reclassified to other income and expense within the income statement. The Company presents its derivative assets and derivative liabilities on a gross basis in the Consolidated Balance Sheets. However, under agreements containing provisions on set-off with certain counterparties, subject to applicable requirements, the Company is allowed to net-settle transactions, with a single net amount payable by one party to the other. The Company is neither required to pledge nor entitled to receive cash collateral related to these derivative transactions. Inventory Inventory consists primarily of component parts to be used in the manufacturing process and finished goods, and is stated at the lower of cost or net realizable value. In addition, the Company purchases and holds inventory to provide adequate component supplies over the life of the underlying products. Cost is computed using standard cost, which approximates actual cost, on a first-in, first-out basis. A charge is recorded to cost of product when inventory is determined to be in excess of anticipated demand or considered obsolete. At the point of loss recognition, a new, lower-cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in the newly established cost basis. Leases The Company determines if an arrangement is a lease at inception. The Company evaluates classification of leases as either operating or finance at commencement and, as necessary, at modification. As of December 31, 2021, the Company did not have any finance leases. Operating leases are included in operating lease right-of-use ("ROU") assets, other accrued liabilities, and operating lease liabilities on the Company's Consolidated Balance Sheets. ROU assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized on the commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made prior to lease commencement and excludes lease incentives. Variable lease payments not dependent on an index or a rate, are expensed as incurred and are not included within the ROU asset and lease liability calculation. Variable lease payments primarily include reimbursements of costs incurred by lessors for common area maintenance and utilities. The Company's lease terms are the noncancelable period, including any rent-free periods provided by the lessor, and include options to extend or terminate the lease when it is reasonably certain that it will exercise that option. At lease inception, and in subsequent periods as necessary, the Company estimates the lease term based on its assessment of extension and termination options that are reasonably certain to be exercised. Lease costs are recognized on a straight-line basis over the lease term. The Company does not separate non-lease components from lease components for all underlying classes of assets. In addition, the Company does not recognize ROU assets and lease liabilities for short-term leases, which have a lease term of twelve months or less and do not include an option to purchase the underlying asset that the Company is reasonably certain to exercise. Lease cost for short-term leases is recognized on a straight-line basis over the lease term. Property and Equipment Property and equipment are recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method, over the estimated useful lives of the following assets: Estimated Useful Life (years) Computers, equipment, and software 1.5 to 10 Furniture and fixtures 5 to 7 Building and building improvements 7 to 40 Land improvements 10 to 40 Leasehold improvements Lease term, not to exceed 10 years Land is not depreciated. Construction-in-process is related to the construction or development of property and equipment that have not yet been placed in service for their intended use. Business Combinations The purchase price of an acquired entity is allocated to tangible assets, liabilities, and intangible assets, including in-process research and development (IPR&D) based on their estimated fair values with the residual of the purchase price recorded as goodwill. The determination of the value of the intangible assets acquired involves certain estimates, such as expected future cash flows, which include consideration of future growth rates and margins, attrition rates, future changes in technology, discount rates, and the expected use of the acquired assets. These factors are also considered in determining the useful life of the acquired intangible assets. IPR&D is initially capitalized at fair value as an intangible asset with an indefinite life and assessed for impairment thereafter. When an IPR&D project is completed, the IPR&D is reclassed as an amortizable purchased intangible asset and amortized over the asset’s estimated useful life. Acquisition related expenses are recognized separately from business combination and are expensed as incurred. The Company's Consolidated Financial Statements include the operating results of acquired businesses from the date of each acquisition. Goodwill and Intangible Assets Goodwill is tested for impairment annually on November 1 or more frequently if certain circumstances indicate the carrying value of goodwill is impaired. Goodwill is tested for impairment at the reporting unit level. A qualitative assessment is first performed to determine whether it is necessary to quantitatively test goodwill for impairment. This initial assessment includes, among others, consideration of macroeconomic conditions and financial performance. If the qualitative assessment indicates that it is more likely than not that an impairment exists, a quantitative analysis is performed by determining the fair value of the reporting unit using a combination of the discounted cash flow and the market approaches. Goodwill is considered impaired if the carrying value of the reporting unit exceeds its fair value. A goodwill impairment loss is recognized for the amount that the carrying amount of the reporting unit, including goodwill, exceeds its fair value, limited to the total amount of goodwill allocated to that reporting unit. Intangible assets consist of existing technology, customer relationships, and trade name, which are amortized over the period of estimated benefit using the straight-line method and estimated useful lives of 4 or 5 years. Other intangible assets acquired in a business combination related to IPR&D projects are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts. Indefinite-lived intangibles are not amortized into the results of operations but instead are evaluated for impairment. If and when development is complete, the associated assets would be deemed finite-lived and would be amortized as cost of revenues over their respective estimated useful lives at that point in time. If the research and development project is abandoned, the acquired IPR&D assets are written off and charged to expense in the period of abandonment. Impairment of Long-lived Assets Long-lived assets, such as property, plant, and equipment, ROU assets, and purchased intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset, or asset group, to estimated undiscounted future cash flows expected to be generated by the asset, or asset group. An impairment charge is recognized by the amount by which the carrying amount of the asset, or asset group, exceeds its fair value. Warranty Reserves The Company generally offers a one-year warranty or limited life-time warranty on most of its hardware products, and a 90-day warranty on the media that contains the software embedded in the products. Warranty costs are recognized as part of the Company's cost of sales based on associated material costs, logistics costs, labor costs, and overhead at the time revenue is recognized. Material costs are estimated primarily based upon the historical costs to repair or replace product returns within the warranty period. Labor, logistics and overhead costs are estimated primarily based upon historical trends in the cost to support customer cases within the warranty period. Warranty reserve is reported within other accrued liabilities in the Consolidated Balance Sheets. Contract Manufacturer Liabilities The Company establishes a liability for non-cancelable, non-returnable purchase commitments with its contract manufacturers for carrying charges, quantities in excess of its demand forecasts, or obsolete material charges for components purchased by the contract manufacturers to meet the Company’s demand forecast or customer orders. The demand forecasts are based upon historical trends and analysis from the Company's sales and marketing organizations, adjusted for overall market conditions. Loss Contingencies The Company is subject to the possibility of various loss contingencies arising in the ordinary course of business. Management considers the likelihood of loss related to the incurrence of a liability as well as its ability to reasonably estimate the amount of loss, in determining loss contingencies. An estimated loss contingency is accrued when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information available to determine whether such accruals should be adjusted and whether new accruals are required. Foreign Currency Assets and liabilities of foreign operations with non-U.S. Dollar functional currency are translated to U.S. Dollars using exchange rates in effect at the end of the period. Revenue and expenses are translated to U.S. Dollars using rates that approximate those in effect during the period. The resulting translation adjustments are included in the Company’s Consolidated Balance Sheets in the stockholders’ equity section as a component of accumulated other comprehensive loss. The Company remeasures monetary assets and monetary liabilities in non-functional currencies and records the resulting foreign exchange transaction gains and losses in other expense, net in the Consolidated Statements of Operations. Revenue Recognition Revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services by following a five-step process, (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price, and (5) recognize revenue when or as the Company satisfies a performance obligation, as further described below. Identify the contract with a customer . The Company generally considers a sales contract and/or agreement with an approved purchase order as a customer contract provided that collection is considered probable, which is assessed based on the creditworthiness of the customer as determined by credit checks, payment histories, and/or other circumstances. The Company combines contracts with a customer if contracts are negotiated with a single commercial substance or contain price dependencies. Identify the performance obligations in the contract . Product performance obligations include hardware, software licenses, and service performance obligations including hardware maintenance, software post-contract support and maintenance, Software-as-a-Service ("SaaS"), education and training, and professional services. Certain software licenses and related post-contract support are combined into a single performance obligation when the maintenance updates are critical to the continued delivery of the software functionality. Determine the transaction price . The transaction price for the Company’s contracts with its customers consists of both fixed and variable consideration provided it is probable that a significant reversal of revenue will not occur when the uncertainty related to variable consideration is resolved. Fixed consideration includes amounts to be contractually billed to the customer while variable consideration includes estimates for rights of return, rebates, and price protection, which are based on historical sales returns and price protection credits, specific criteria outlined in rebate agreements, and other factors known at the time. The Company generally invoices customers for hardware, software licenses and related maintenance arrangements at time of delivery, and professional services either upfront or upon meeting certain milestones. Customer invoices are generally due within 30 to 90 days after issuance. The Company’s contracts with customers typically do not include significant financing components as the period between the transfer of performance obligations and timing of payment are generally within one year. Allocate the transaction price to the performance obligations in the contract . For contracts that contain multiple performance obligations, the Company allocates the transaction price to the performance obligations on a relative stand-alone selling price ("SSP") basis. SSP is based on multiple factors including, but not limited to historical discounting trends for products and services, pricing practices in different geographies and through different sales channels, gross margin objectives, internal costs, competitor pricing strategies, and industry technology lifecycles. Recognize revenue when or as the Company satisfies a performance obligation . Revenue for hardware and certain software licenses, are recognized at a point in time, which is generally upon shipment or delivery. Certain software licenses combined with post-contract support and maintenance are recognized over time on a ratable basis over the term of the license. Revenue for maintenance, software post-contract support and maintenance, and SaaS is recognized over time on a ratable basis over the contract term. Revenue from education, training, and professional services is recognized over time as services are completed or ratably over the contractual period of generally one year or less. Deferred product revenue represents unrecognized revenue related to undelivered product commitments and other shipments that have not met revenue recognition criteria. Deferred service revenue represents billed amounts for service contracts, which include technical support, hardware and software maintenance, professional services, SaaS, and education and training, for which services have not been rendered. Revenue is recognized net of any taxes collected, which are subsequently remitted to governmental authorities. Deferred Commissions Sales commissions earned by the Company’s sales force are considered incremental and recoverable costs of obtaining a contract with a customer. These costs are recorded as prepaid expenses or other long-term assets and are deferred and then amortized over a period of benefit which is typically over the term of the customer contracts. Amortization expense is included in sales and marketing expenses in the accompanying Consolidated Statements of Operations. Research and Development Costs to research, design, and develop the Company's products are expensed as incurred. Software Development Costs Capitalization of software development costs for software to be sold, leased, or otherwise marketed begins when a product's technological feasibility has been established and ends when a product is available for general release to customers. Generally, the Company's products are released soon after technological feasibility has been established. As a result, costs incurred between achieving technological feasibility and product general availability have not been significant. The Company capitalizes costs associated with internal-use software systems during the application development stage. Such capitalized costs include external direct costs incurred in developing or obtaining the applications and payroll and payroll-related costs for employees, who are directly associated with the development of the applications. Advertising Advertising costs are charged to sales and marketing expense as incurred. Advertising expense was $26.6 million , $21.7 million, and $14.6 million, for 2021, 2020, and 2019, respectively. Share-Based Compensation The Company measures and recognizes compensation cost for all share-based awards made to employees and directors, including employee stock options, restricted stock awards ("RSAs"), restricted stock units ("RSUs"), performance share awards ("PSAs") and employee stock purchases related to the Employee Stock Purchase Plan ("ESPP"). For service condition only awards, share-based compensation expense is based on the fair value of the underlying awards and amortized on a straight-line basis. For PSAs, share-based compensation expense is amortized on a straight-line basis for each separate vesting portion of the awards. The Company accounts for forfeitures as they occur. The Company utilizes the Black-Scholes-Merton (“BSM”) option-pricing model to estimate the fair value of its ESPP purchase rights. The BSM model requires various highly subjective assumptions that represent management's best estimates of volatility, risk-free interest rate, expected life, and dividend yield. The Company estimates expected volatility based on the implied volatility of market-traded options, on the Company's common stock, adjusted for other relevant factors including historical volatility of the Company’s common stock over the most recent period commensurate with the estimated expected life of the Company’s ESPP. The expected life of ESPP purchase rights approximates the offering period. The Company determines the grant date fair value of its RSUs, RSAs, and PSAs based on the closing market price of the Company’s common stock on the date of grant, adjusted by the present value of the 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. For market-based RSUs, the Company estimates the fair value and derived service period using the Monte Carlo simulation option pricing model ("Monte Carlo model"). The determination of the grant date fair value and derived service periods using the Monte Carlo model is affected by the Company's stock price, comparative market-based returns, as well as various highly subjective assumptions that represent management's best estimates of volatility, risk-free interest rate, and dividend yield. The Company estimates expected volatility based on the implied volatility of market-traded options, on the Company's common stock, adjusted for other relevant factors, including historical volatility of the Company’s common stock over the contractual life of the Company's market-based RSUs. Provision for Income Taxes Deferred tax assets and liabilities are recognized for the expected tax consequences of temporary differences between the tax basis of assets and liabilities and their reported amounts. Valuation allowances are recorded to reduce deferred tax assets to the amount that will more likely than not be realized. The Company accounts for uncertainty in income taxes using a two-step approach to recognize and measure uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. The Company classifies the liability for unrecognized tax benefits as current to the extent that the Company anticipates payment (or receipt) of cash within one year. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes. The Company accounts for the current impacts of U.S. tax on certain foreign subsidiaries income, which is referred to as Global Intangible Low-Taxed Income in the year earned. Concentrations of Risk Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, investments, derivatives, and accounts receivable. The Company invests only in high-quality credit instruments and maintains its cash, cash equiv

Business Combinations

Business Combinations	12 Months Ended
Business Combinations	Dec. 31, 2021
Business Combination and Asset Acquisition [Abstract]
Business Combinations	Note 2. Business Combinations 2021 Acquisitions Pro forma results of operations for the acquisitions have not been presented, as the financial impact to the Company's consolidated results of operations is not material. The goodwill recognized for these acquisitions is primarily attributable to expected synergies and is not deductible for U.S. federal income tax purposes. Apstra 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. WiteSand During the fourth quarter of 2021, Juniper acquired 100% ownership of WiteSand Systems Inc. ("WiteSand"), a company that provides cloud-based network infrastructure solutions, for a purchase consideration of $21.8 million in cash. The preliminary purchase price allocation is subject to potential measurement period adjustments relating to certain tax and legal matters. The acquisition is expected to expand upon the Company's AI-driven enterprise network solution. 2020 Acquisitions 128 Technology On November 30, 2020, the Company acquired 100% ownership of 128 Technology for $448.2 million. The purchase consideration consisted of cash of $446.8 million and approximately $1.4 million in share-based awards attributable to employee services prior to the acquisition. The acquisition is expected to enhance Juniper's AI-driven enterprise network portfolio by uniting 128 Technology’s session-smart networking with Juniper's campus and branch solutions driven by Mist AI. Under the terms of the acquisition agreement with 128 Technology, the Company assumed certain share-based awards for continuing employees, which were granted in contemplation of future services. The fair value of these share-based awards was $29.3 million, which will be expensed as share-based compensation over the remaining service period. Netrounds On October 26, 2020, the Company acquired 100% ownership of Netrounds for $33.6 million of cash. The acquisition of Netrounds, a company that provides a programmable, software-based active test and service assurance platform suitable for fixed and mobile networks, is expected to enhance Juniper’s automated WAN solutions by further simplifying operations for service providers and ensuring positive end-user experiences. Acquisition Costs The Company recognized $8.9 million and $24.6 million of acquisition-related costs during the years ended December 31, 2021 and December 31, 2020, respectively. These acquisition-related costs were expensed in the period incurred within general and administrative expense in the Company's Consolidated Statements of Operations. The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition dates (in millions): 2021 2020 Apstra WiteSand 128 Technology Netrounds Cash and cash equivalents $ 1.8 $ 1.5 $ 29.1 $ 1.0 Goodwill 84.0 10.2 298.8 24.7 Intangible assets 87.8 9.3 116.7 8.7 Other assets acquired 12.6 0.8 14.3 0.8 Liabilities assumed (6.8) — (10.7) (1.6) Total $ 179.4 $ 21.8 $ 448.2 $ 33.6 The following table summarizes the fair value of the separately identifiable intangible assets at the time of acquisition and the period over which each intangible asset will be amortized (in millions, except years): 2021 2020 Apstra WiteSand 128 Technology Netrounds Weighted Amount Weighted Amount Weighted Amount Weighted Amount Intangible assets: Existing technology 5 $ 80.5 5 $ 9.3 5 $ 88.0 4 $ 5.3 Customer relationships 1.5 7.3 — — 5 27.0 5 3.4 Backlog — — — — 1.5 1.7 — — Total intangible assets acquired $ 87.8 $ 9.3 $ 116.7 $ 8.7

Cash Equivalents and Investment

Cash Equivalents and Investments	12 Months Ended
Cash Equivalents and Investments	Dec. 31, 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 December 31, 2021 and December 31, 2020 (in millions): As of December 31, 2021 As of December 31, 2020 Amortized Gross Unrealized Gross Unrealized Estimated Fair Amortized Gross Unrealized Gross Unrealized Estimated Fair Fixed income securities: Asset-backed and mortgage-backed securities $ 139.1 $ — $ (0.5) $ 138.6 $ 76.5 $ 0.2 $ — $ 76.7 Certificates of deposit 5.0 — — 5.0 32.9 — — 32.9 Commercial paper 75.8 — — 75.8 89.3 — — 89.3 Corporate debt securities 443.3 0.7 (1.5) 442.5 632.0 5.5 (0.1) 637.4 Foreign government debt securities 12.8 — (0.1) 12.7 4.6 — — 4.6 Time deposits 35.2 — — 35.2 255.6 — — 255.6 U.S. government agency securities 26.8 — (0.1) 26.7 65.3 0.2 — 65.5 U.S. government securities 73.5 0.1 — 73.6 232.8 1.0 — 233.8 Total fixed income securities 811.5 0.8 (2.2) 810.1 1,389.0 6.9 (0.1) 1,395.8 Privately-held debt and redeemable preferred stock securities 9.6 37.4 — $ 47.0 18.3 37.4 — 55.7 Total available-for-sale debt securities $ 821.1 $ 38.2 $ (2.2) $ 857.1 $ 1,407.3 $ 44.3 $ (0.1) $ 1,451.5 Reported as: Cash equivalents $ 47.2 $ — $ — $ 47.2 $ 333.7 $ — $ — $ 333.7 Short-term investments 306.8 0.7 (0.1) 307.4 404.3 1.2 — 405.5 Long-term investments 457.5 0.1 (2.1) 455.5 651.0 5.7 (0.1) 656.6 Other long-term assets 9.6 37.4 — 47.0 18.3 37.4 — 55.7 Total $ 821.1 $ 38.2 $ (2.2) $ 857.1 $ 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 December 31, 2021 (in millions): Amortized Estimated Fair Due in less than one year $ 354.0 $ 354.6 Due between one and five years 457.5 455.5 Total $ 811.5 $ 810.1 As of December 31, 2021, the Company's unrealized loss of $2.2 million resulted from 393 investments that were primarily 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 tha t no allowance for credit losses was required to be recognized during the years ended December 31, 2021 and December 31, 2020. During the year ended December 31, 2021, the Company had gross realized gains of $15.3 million and no material gross realized losses from available-for-sale debt securities. During the years ended December 31, 2020, and 2019, 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 December 31, 2021 and 2020 (in millions): As of December 31, 2021 2020 Equity investments with readily determinable fair value Money market funds $ 382.0 $ 536.6 Mutual funds 33.4 29.3 Publicly-traded equity securities 8.1 6.6 Equity investments without readily determinable fair value 150.1 146.2 Total equity securities $ 573.6 $ 718.7 Reported as: Cash equivalents $ 371.5 $ 519.8 Short-term investments 8.1 6.6 Prepaid expenses and other current assets 15.1 9.9 Other long-term assets 178.9 182.4 Total $ 573.6 $ 718.7 During the years ended December 31, 2021, 2020, and 2019, 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 December 31, 2021, the carrying value of restricted cash and investments was $64.1 million, of which $32.2 million was included in prepaid expenses and other current assets and $31.9 million was included in other long-term assets on the Consolidated Balance Sheets. The following table provides a reconciliation of cash, cash equivalents, and restricted cash included in the Consolidated Balance Sheets as of December 31, 2021 and December 31, 2020 (in millions): As of December 31, 2021 2020 Cash and cash equivalents $ 922.5 $ 1,361.9 Restricted cash included in Prepaid expenses and other current assets 17.2 19.2 Restricted cash included in Other long-term assets 3.0 1.9 Total cash, cash equivalents, and restricted cash $ 942.7 $ 1,383.0

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 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 Consolidated Balance Sheets (in millions): Fair Value Measurements at December 31, 2021 Fair Value Measurements at December 31, 2020 Quoted Prices in Significant Other Significant Other Total Quoted Prices in Significant Other Significant Other Total Assets: Available-for-sale debt securities: Asset-backed and mortgage-backed securities $ — $ 138.6 $ — $ 138.6 $ — $ 76.7 $ — $ 76.7 Certificates of deposit — 5.0 — 5.0 — 32.9 — 32.9 Commercial paper — 75.8 — 75.8 — 89.3 — 89.3 Corporate debt securities — 442.5 — 442.5 — 637.4 — 637.4 Foreign government debt securities — 12.7 — 12.7 — 4.6 — 4.6 Time deposits — 35.2 — 35.2 — 255.6 — 255.6 U.S. government agency securities — 26.7 — 26.7 — 65.5 — 65.5 U.S. government securities 42.3 31.3 — 73.6 140.0 93.8 — 233.8 Privately-held debt and redeemable preferred stock securities — — 47.0 47.0 — — 55.7 55.7 Total available-for-sale debt securities 42.3 767.8 47.0 857.1 140.0 1,255.8 55.7 1,451.5 Equity securities: Money market funds 382.0 — — 382.0 536.6 — — 536.6 Mutual funds 33.4 — — 33.4 29.3 — — 29.3 Publicly-traded equity securities 8.1 — — 8.1 6.6 — — 6.6 Total equity securities 423.5 — — 423.5 572.5 — — 572.5 Derivative assets: Foreign exchange contracts — 9.2 — 9.2 — 38.0 — 38.0 Interest rate contracts — 47.1 — 47.1 — 51.0 — 51.0 Total derivative assets — 56.3 — 56.3 — 89.0 — 89.0 Total assets measured at fair value on a recurring basis $ 465.8 $ 824.1 $ 47.0 $ 1,336.9 $ 712.5 $ 1,344.8 $ 55.7 $ 2,113.0 Liabilities: Derivative liabilities: Foreign exchange contracts $ — $ (24.0) $ — $ (24.0) $ — $ (0.5) $ — $ (0.5) Interest rate contracts — (2.5) — (2.5) — — — — Total derivative liabilities — (26.5) — (26.5) — (0.5) — (0.5) Total liabilities measured at fair value on a recurring basis $ — $ (26.5) $ — $ (26.5) $ — $ (0.5) $ — $ (0.5) Total assets, reported as: Cash equivalents $ 371.6 $ 47.2 $ — $ 418.8 $ 519.8 $ 333.7 $ — $ 853.5 Short-term investments 41.5 274.0 — 315.5 101.0 311.1 — 412.1 Long-term investments 8.8 446.7 — 455.5 45.6 611.0 — 656.6 Prepaid expenses and other current assets 15.1 8.8 — 23.9 9.9 28.0 — 37.9 Other long-term assets 28.8 47.4 47.0 123.2 36.2 61.0 55.7 152.9 Total assets measured at fair value on a recurring basis $ 465.8 $ 824.1 $ 47.0 $ 1,336.9 $ 712.5 $ 1,344.8 $ 55.7 $ 2,113.0 Fair Value Measurements at December 31, 2021 Fair Value Measurements at December 31, 2020 Quoted Prices in Significant Other Significant Other Total Quoted Prices in Significant Other Significant Other Total Total liabilities, reported as: Other accrued liabilities $ — $ (14.9) $ — $ (14.9) $ — $ (0.3) $ — $ (0.3) Other long-term liabilities — (11.6) — (11.6) — (0.2) — (0.2) Total liabilities measured at fair value on a recurring basis $ — $ (26.5) $ — $ (26.5) $ — $ (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 years ended December 31, 2021 and 2020, 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 financing activities and the investee's capital structure. During the year ended December 31, 2021, the Company realized a gain of $13.4 million from disposal of securities with an aggregate cost of $9.6 million related to privately-held debt and redeemable preferred stock. 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 December 31, 2021 and December 31, 2020, there have been no material 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 years ended December 31, 2021, 2020, and 2019. As of December 31, 2021 and 2020, the Company had no liabilities measured at fair value on a nonrecurring basis. Assets and Liabilities Not Measured at Fair Value The carrying amounts of the Company's accounts receivable, accounts payable, and other accrued liabilities approximate fair value due to their short maturities. As of December 31, 2021 and December 31, 2020, the estimated fair value of the Company's total outstanding debt in the Consolidated Balance Sheets was $1,845.6 million

Derivative Instruments

Derivative Instruments	12 Months Ended
Derivative Instruments	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Note 5. Derivative Instruments The notional amount of the Company's derivative instruments is summarized as follows (in millions): As of December 31, 2021 2020 Designated derivatives: Cash flow hedges: Foreign currency contracts $ 873.9 $ 722.1 Interest rate lock contracts 650.0 650.0 Fair value hedges: Interest rate swap contracts 600.0 300.0 Total designated derivatives $ 2,123.9 $ 1,672.1 Non-designated derivatives 144.6 174.1 Total $ 2,268.5 $ 1,846.2 The fair value of derivative instruments on the Consolidated Balance Sheets was as follows: As of December 31, Balance Sheet Location 2021 2020 Derivative assets: Derivatives designated as hedging instruments: Foreign currency contracts as cash flow hedges Other current assets $ 8.7 $ 27.8 Foreign currency contracts as cash flow hedges Other long-term assets 0.4 10.0 Interest rate lock contracts Other long-term assets 45.0 30.7 Interest rate swap contracts Other long-term assets 2.1 20.3 Total derivatives designated as hedging instruments $ 56.2 $ 88.8 Derivatives not designated as hedging instruments Other current assets 0.1 0.2 Total derivative assets $ 56.3 $ 89.0 Derivative liabilities: Derivatives designated as hedging instruments: Foreign currency contracts Other accrued liabilities $ 14.8 $ 0.2 Foreign currency contracts Other long-term liabilities 9.1 0.2 Interest rate swap contracts Other long-term liabilities 2.5 — Total derivatives designated as hedging instruments $ 26.4 $ 0.4 Derivatives not designated as hedging instruments Other accrued liabilities 0.1 0.1 Total derivative liabilities $ 26.5 $ 0.5 Offsetting of Derivative Instruments The Company presents its derivative instruments at gross fair values in the Consolidated Balance Sheets. As of December 31, 2021 and December 31, 2020 the potential effects of set-off associated with the derivative contracts would be a reduction to both derivative assets and derivative liabilities by $17.5 million and $0.5 million, respectively. 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 nine 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 four years . Effect of Derivative Instruments on the Consolidated Statements of Operations For cash flow hedges, the Company recognized an unrealized loss of $9.1 million , unrealized gain of $63.5 million and unrealized loss of $6.3 million in accumulated other comprehensive loss for the effective portion of its derivative instruments during the years ended December 31, 2021, 2020, and 2019, respectively. For foreign currency forward contracts, the Company reclassified a gain of $28.9 million, and losses of $9.0 million and $3.8 million out of accumulated other comprehensive loss to cost of revenues and operating expenses in the Consolidated Statement of Operations during the years ended December 31, 2021, 2020, and 2019, respectively. As of December 31, 2021, an estimated $6.1 million of unrealized net loss 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 . The outstanding non-designated derivative instruments are carried at fair value. Changes in the fair value of these derivatives recorded in other expense, net within the Consolidated Statements of Operations were not material during the years ended December 31, 2021, 2020, and 2019, respectively. See Note 1, Description of Business, Basis of Presentation and Significant Accounting Policies, for the Company’s policy regarding the offsetting of derivative assets and derivative liabilities.

Goodwill and Purchased Intangib

Goodwill and Purchased Intangible Assets	12 Months Ended
Goodwill and Purchased Intangible Assets	Dec. 31, 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 was as follows (in millions): Total December 31, 2019 $ 3,337.1 Additions due to business combinations 332.5 December 31, 2020 3,669.6 Additions due to business combinations 92.5 December 31, 2021 $ 3,762.1 We conducted our annual impairment test of goodwill during the fourth quarter of 2021; the estimated fair value of our reporting unit was substantially in excess of the carrying value. There was no goodwill impairment during the years ended December 31, 2021, 2020, and 2019. Purchased Intangible Assets The Company’s purchased intangible assets, net, were as follows (in millions): As of December 31, 2021 As of December 31, 2020 Gross Accumulated Accumulated Impairments and Net Gross Accumulated Accumulated Impairments and Net Finite-lived intangible assets: Technologies and patents $ 913.1 $ (660.7) $ (55.1) $ 197.3 $ 823.5 $ (598.2) $ (55.1) $ 170.2 Customer contracts, support agreements, and related relationships 136.3 (98.6) (2.8) 34.9 129.2 (84.4) (2.8) 42.0 Trade names and other 9.6 (6.5) — 3.1 9.6 (4.1) — 5.5 Total 1,059.0 (765.8) (57.9) 235.3 962.3 (686.7) (57.9) 217.7 Indefinite-lived intangible assets: IPR&D 49.0 — — 49.0 49.0 — — 49.0 Total purchased intangible assets $ 1,108.0 $ (765.8) $ (57.9) $ 284.3 $ 1,011.3 $ (686.7) $ (57.9) $ 266.7 Amortization expense related to purchased intangible assets with finite lives was $79.5 million, $40.6 million, and $34.7 million for the years ended December 31, 2021, 2020, and 2019, respectively. There were no significant impairment charges related to purchased intangible assets during the years ended December 31, 2021, 2020, and 2019. As of December 31, 2021, the estimated future amortization expense of purchased intangible assets with finite lives was as follows (in millions): Years Ending December 31, Amount 2022 $ 74.9 2023 68.7 2024 49.2 2025 39.6 2026 2.9 Total $ 235.3

Other Financial Information

Other Financial Information	12 Months Ended
Other Financial Information	Dec. 31, 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 December 31, 2021 2020 Production and service materials $ 208.6 $ 158.1 Finished goods 75.6 63.8 Total inventory $ 284.2 $ 221.9 Reported as: Inventory $ 272.6 $ 210.2 Other long-term assets 11.6 11.7 Total inventory $ 284.2 $ 221.9 Property and Equipment, Net Property and equipment, net, consisted of the following (in millions): As of December 31, 2021 2020 Computers and equipment $ 1,023.5 $ 1,057.5 Software 226.8 231.1 Leasehold improvements 197.6 223.8 Furniture and fixtures 46.8 49.6 Building and building improvements 269.3 256.0 Land and land improvements 243.5 243.5 Construction-in-process 11.2 17.7 Property and equipment, gross 2,018.7 2,079.2 Accumulated depreciation (1,315.7) (1,316.9) Property and equipment, net $ 703.0 $ 762.3 Depreciation expense was $151.0 million, $166.2 million, and $184.0 million in 2021, 2020, and 2019, respectively. Warranties Changes in the Company’s warranty reserve were as follows (in millions): As of December 31, 2021 2020 Beginning balance $ 30.2 $ 31.4 Provisions made during the period, net 39.5 37.1 Actual costs incurred during the period (36.7) (38.3) Ending balance $ 33.0 $ 30.2 Revenue See Note 12, Segments, for disaggregated revenue by customer solution, customer vertical, and geographic region. Product revenue of $74.0 million included in deferred revenue at January 1, 2021 was recognized during the year ended December 31, 2021. Service revenue of $770.4 million included in deferred revenue at January 1, 2021 was recognized during the year ended December 31, 2021. Remaining Performance Obligations Remaining Performance Obligations (RPO) are comprised mainly of deferred product and service revenue, and to a lesser extent, unbilled service revenue from non-cancellable contracts for which the Company has not invoiced and has an obligation to perform, and for which revenue has not yet been recognized in the financial statements. The following table summarizes the breakdown of RPO as of December 31, 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 $ 135.8 $ 117.1 $ 15.6 $ 3.1 Service 1,296.0 828.7 371.1 96.2 Total $ 1,431.8 $ 945.8 $ 386.7 $ 99.3 Deferred Commissions Deferred commissions were $34.9 million and $27.4 million as of December 31, 2021 and 2020, respectively. During the years ended December 31, 2021 and 2020, amortization expense for the deferred commissions were $189.8 million and $145.9 million, respectively, and there were no impairment charges recognized. Other Expense, Net Other expense, net consisted of the following (in millions): Years Ended December 31, 2021 2020 2019 Interest income $ 14.9 $ 36.3 $ 79.1 Interest expense (50.8) (77.0) (88.7) Gain (loss) on investments, net 17.6 13.3 (3.8) Other 1.5 (5.5) 0.9 Other expense, net $ (16.8) $ (32.9) $ (12.5) Interest income primarily includes interest earned on the Company’s cash, cash equivalents and investments. Interest expense primarily includes interest, net of capitalized interest expense, from long-term debt and customer financing arrangements. Gain (loss) on investments, net, primarily includes gains (losses) from the sale of investments in public and privately-held companies, and any observable changes in fair value and impairment charges recorded on these investments. Other typically consists of foreign exchange gains and losses and other non-operational income and expense items.

Restructuring Charges

Restructuring Charges	12 Months Ended
Restructuring Charges	Dec. 31, 2021
Restructuring and Related Activities [Abstract]
Restructuring Charges	Note 8. Restructuring Charges The following table presents restructuring charges included in the Consolidated Statements of Operations (in millions): Years Ended December 31, 2021 2020 2019 Severance $ 13.6 $ 62.8 $ 21.5 Facility consolidations 8.1 5.2 2.1 Contract terminations and other 21.2 — 11.7 Total $ 42.9 $ 68.0 $ 35.3 Reported as: Restructuring charges $ 42.9 $ 68.0 $ 35.3 Total $ 42.9 $ 68.0 $ 35.3 2021 Restructuring Plan 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. In connection with the 2021 Restructuring Plan, we incurred cumulative charges of $42.9 million for the twelve months ended December 31, 2021. These costs were reported as restructuring charges in the Consolidated Statements of Operations. Prior Restructuring Activities In 2020, the Company initiated a restructuring plan (the "2020 Restructuring Plan") designed to realign its workforce with the Company's sales strategy, enhance productivity and cost efficiencies, and enable reinvestment in certain key priority areas, which resulted in severance costs and other exit related costs, including impairment charges. In connection with the 2020 Restructuring Plan, during the fourth quarter of 2020, the Company implemented a voluntary early retirement program for employees who met certain eligibility requirements, which resulted in additional severance costs that were recorded to restructuring charges in the Consolidated Statement of Operations. In 2019, the Company initiated a restructuring plan (the "2019 Restructuring Plan") to realign its workforce with the Company's sales strategy, improve productivity, and enhance cost efficiencies, which resulted in severance, facility consolidation, and contract termination costs that were recorded to restructuring charges in the Consolidated Statement of Operations. Restructuring Liabilities Restructuring liabilities are reported within other accrued liabilities in the Consolidated Balance Sheets. The following table provides a summary of changes in the restructuring liabilities associated with the 2021 Restructuring Plan and 2020 Restructuring Plan (in millions): December 31, Charges/ Cash Other December 31, Severance $ 50.7 $ 13.6 $ (63.9) $ 1.0 $ 1.4 Facility consolidations — 8.1 — (8.1) — Contract terminations and other — 21.2 (4.5) (5.8) 10.9 Total $ 50.7 $ 42.9 $ (68.4) $ (12.9) $ 12.3

Debt and Financing

Debt and Financing	12 Months Ended
Debt and Financing	Dec. 31, 2021
Debt Instruments [Abstract]
Debt and Financing	Note 9. Debt and Financing Debt The following table summarizes the Company's total debt (in millions, except percentages): As of December 31, Maturity Date Effective Interest 2021 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 (12.9) (16.8) Hedge accounting fair value adjustments () (0.3) 20.3 Total $ 1,686.8 $ 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 December 2020, the Company issued $400.0 million aggregate principal amount of 1.20% senior notes due 2025 ("2025-II Notes") and $400.0 million aggregate principal amount of 2.00% senior notes due 2030 ("2030 Notes"). The net proceeds from the issuances of the 2025-II Notes and the 2030 Notes, together with cash on hand, were used for the repayment of $500.0 million aggregate principal amount of the Company's 4.50% senior notes due 2024 and $300.0 million aggregate principal amount of the Company's 4.35% senior notes due 2025. In December 2020, the Company, through a cash tender offer, partly repurchased $234.2 million in aggregate principal amount of 2024 Notes and $142.0 million in aggregate principal amount of 2025-I Notes. The repayments resulted in a loss on extinguishment of debt of $55.0 million, consisting primarily of a premium on the tender offer and acceleration of unamortized debt discount and fees on the redeemed debt, which was recorded within the Consolidated Statements of Operations. 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. As of December 31, 2021, the Company's aggregate debt maturities based on outstanding principal were as follows (in millions): Years Ending December 31, Amount 2022 $ — 2023 — 2024 — 2025 400.0 2026 — Thereafter 1,300.0 Total $ 1,700.0 The Company may redeem the Notes, either in whole or in part, at any time at a redemption price equal to the greater of (i) 100% of the aggregate principal amount of the Notes to be redeemed or (ii) the sum of the present values of the remaining scheduled payments discounted to the redemption date, plus, in either case, accrued and unpaid interest, if any. In the event of a change of control repurchase event, the holders of the Notes may require the Company to repurchase for cash all or part of the Notes at a purchase price equal to 101% of the aggregate principal amount, plus accrued and unpaid interest, if any. 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 that governs 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 December 31, 2021, the Company was in compliance with all covenants in the indenture governing the Notes. Revolving Credit Facility In April 2019, the Company entered into a credit agreement (the "Credit Agreement") with certain institutional lenders that provides for a five-year $500.0 million unsecured revolving credit facility (the "Revolving Credit Facility"), with an option to increase the Revolving Credit Facility by up to an additional $200.0 million, subject to the lenders' approval. Proceeds of loans made under the Revolving Credit Facility may be used by the Company for working capital and general corporate purposes. The Revolving Credit Facility will terminate in April 2024. Borrowings under the Revolving Credit Facility will bear interest, at either (i) a floating rate per annum equal to the base rate plus a margin of between 0.00% and 0.375%, depending on the Company's public debt rating or (ii) a per annum rate equal to the reserve adjusted Eurocurrency rate, plus a margin of between 0.910% and 1.375%, depending on the Company's public debt rating. Base rate is defined as the greatest of (A) Citibank's base rate, (B) the federal funds rate plus 0.500% or (C) the ICE Benchmark Administration Settlement Rate applicable to dollars for a period of one month plus 1.00%. The Eurocurrency rate is determined for U.S. dollars and Pounds Sterling as the rate at which deposits in such currency are offered in the London interbank market for the applicable interest period and for Euro as the rate specified for deposits in Euro with a maturity comparable to the applicable interest period. On December 17, 2021, an amendment to the Credit Agreement was executed that defines the Secured Overnight Financing Rate (SOFR) as the benchmark rate for U.S. dollar borrowings in the absence of LIBOR, and the Sterling Overnight Index Average (SONIA) as the benchmark rate for Pounds Sterling borrowings following the cessation of GBP LIBOR on December 31, 2021. The Revolving Credit Facility requires the Company to maintain a leverage ratio no greater than 3.0x (provided that if a material acquisition has been consummated, the Company is permitted to maintain a leverage ratio no greater than 3.5x for up to four quarters) and an interest coverage ratio no less than 3.0x during the term of the credit facility. As of December 31, 2021, the Company had not borrowed any funds under the Credit Agreement and was in compliance with all covenants in the Credit Agreement. Financing Arrangements The Company provides certain customers with access to extended financing arrangements that allow for longer payment terms than those typically provided by the Company by factoring accounts receivable to third-party financing providers ("financing providers"). The program does not and is not intended to affect the timing of the Company's revenue recognition. Under the financing arrangements, proceeds from the financing providers are due to the Company within 1 to 90 days from the sale of the receivable. In these transactions with the financing providers, the Company surrenders control over the transferred assets. Pursuant to the financing arrangements for the sale of receivables, the Company sold receivables of $31.9 million, $57.5 million and $64.0 million during the years ended December 31, 2021, 2020, and 2019, respectively. The Company received cash proceeds from financing providers of $32.5 million, $57.4 million, and $69.7 million during the years ended December 31, 2021, 2020, and 2019, respectively. As of December 31, 2021 and December 31, 2020, the amounts owed by the financing providers were $3.2 million and $3.9 million, respectively, which were recorded in accounts receivable on the Company’s Consolidated Balance Sheets.

Equity

Equity	12 Months Ended
Equity	Dec. 31, 2021
Equity [Abstract]
Equity	Note 10. Equity The following table summarizes dividends paid, stock repurchases and retirements under the Company's stock repurchase programs, and stock repurchases for tax withholdings (in millions, except per share amounts): Dividends Stock Repurchases Total Year Per Share Amount Shares Average price () Amount Tax Withholding Amount 2021 $ 0.80 $ 259.1 15.7 $ 27.56 $ 433.3 $ 10.2 $ 702.6 2020 $ 0.80 $ 264.1 17.9 $ 23.47 $ 375.0 $ 6.2 $ 645.3 2019 $ 0.76 $ 260.1 20.1 $ 25.36 $ 550.0 $ 5.0 $ 815.1 ________________________________ () $23.47 average price per share for 2020 includes $375.0 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 2021, 2020, and 2019, the Company declared and paid quarterly cash dividends of $0.20, $0.20 and $0.19 per common share, totaling $259.1 million, $264.1 million, and $260.1 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 December 31, 2021. Stock Repurchase Activities In January 2018, the Board approved a $2.0 billion share repurchase program ("2018 Stock Repurchase Program"). In October 2019, the Board authorized a $1.0 billion increase to the 2018 Stock Repurchase Program for a total of $3.0 billion. As part of the 2018 Stock Repurchase Program, in April 2019, the Company entered into an accelerated share repurchase program ("ASR") and repurchased $300.0 million of the Company's common stock. The aggregate number of shares ultimately repurchased of 11.6 million shares of the Company's common stock was determined based on a volume weighted average repurchase price, less an agreed upon discount, of $25.79 per share. The shares received by the Company were retired, accounted for as a reduction to stockholder’s equity in the Consolidated Balance Sheets, and treated as a repurchase of common stock for purposes of calculating earnings per share. As part of the 2018 Stock Repurchase Program, in October 2019, the Company entered into an ASR with a financial institution to repurchase an aggregate of $200.0 million of the Company's outstanding common stock. The Company made an up-front payment of $200.0 million pursuant to the ASR and received and retired an initial 6.4 million shares of the Company's common stock for an aggregate price of $160.0 million based on the market price of $25.15 per share of the Company’s common stock on the date of the transaction. In January 2020, the ASR was completed, and an additional 1.8 million shares were received for a total repurchase of 8.2 million shares of the Company's common stock at a volume weighted average repurchase price, less an agreed upon discount, of $24.44 per share. The shares received by the Company were retired, accounted for as a reduction to stockholder’s equity in the Consolidated Balance Sheets, and treated as a repurchase of common stock for purposes of calculating earnings per share. During the fiscal year ended December 31, 2021, the Company repurchased 15.7 million shares of its common stock in the open market at an average price of $27.56 per share for an aggregate purchase price of $433.3 million under the 2018 Stock Repurchase Program. As of December 31, 2021, there were $0.9 billion of authorized funds remaining under the 2018 Stock Repurchase Program. See Note 16, Subsequent Events, for a discussion of the Company's stock repurchase activity subsequent to December 31, 2021. 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 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 our financial statements as they reduce the number of shares that would have been issued upon vesting. Accumulated Other Comprehensive Income (Loss), Net of Tax The components of accumulated other comprehensive income (loss), net of related taxes, for the years ended December 31, 2021, 2020, and 2019 were as follows (in millions): Unrealized Gains/Losses on Available-for- Sale Debt Securities (1) Unrealized Gains/Losses on Cash Flow Hedges (2) Foreign Total Balance as of December 31, 2018 $ 25.5 $ (0.9) $ (42.8) $ (18.2) Other comprehensive income (loss) before reclassifications 4.6 (8.9) (1.1) (5.4) Amount reclassified from accumulated other comprehensive income (loss) (0.4) 5.5 — 5.1 Other comprehensive income (loss), net 4.2 (3.4) (1.1) (0.3) Balance as of December 31, 2019 $ 29.7 $ (4.3) $ (43.9) $ (18.5) Other comprehensive income before reclassifications 5.7 54.4 7.7 67.8 Amount reclassified from accumulated other comprehensive income (loss) (1.3) 7.6 — 6.3 Other comprehensive income, net 4.4 62.0 7.7 74.1 Balance as of December 31, 2020 $ 34.1 $ 57.7 $ (36.2) $ 55.6 Other comprehensive loss before reclassifications (5.0) (13.5) (12.8) (31.3) Amount reclassified from accumulated other comprehensive income (loss) (1.2) (25.2) — (26.4) Other comprehensive loss, net (6.2) (38.7) (12.8) (57.7) Balance as of December 31, 2021 $ 27.9 $ 19.0 $ (49.0) $ (2.1) ________________________________ (1) The reclassifications out of accumulated other comprehensive income (loss) during the years ended December 31, 2021, 2020 , and 2019 for realized gains on available-for-sale debt securities were not material, and were included in other expense, net, in the Consolidated Statements of Operations. (2) The reclassifications out of accumulated other comprehensive income (loss) for realized gains and losses on cash flow hedges was $28.9 million for the year ended December 31, 2021 and not material for the years ended 2020 and 2019. The reclassified amounts were included within cost of revenues, research and development, sales and marketing, and general and administrative in the Consolidated Statements of Operations.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Employee Benefit Plans	Note 11. Employee Benefit Plans Equity Incentive Plans The Company’s equity incentive plans include the 2015 Equity Incentive Plan (the “2015 Plan”) and the 2008 Employee Stock Purchase Plan (the “ESPP”). The Company has granted RSUs and PSAs under the 2015 Plan and purchase rights under the ESPP. In addition, in connection with certain past acquisitions, the Company has assumed or substituted stock options, RSUs, RSAs, and PSAs granted under the stock plans of the acquired companies. Such awards were converted into or replaced with the Company's stock options, RSUs, RSAs, and PSAs, respectively. The 2015 Plan was adopted and approved by the Company's stockholders in May 2015 and had an initial authorized share reserve of 38.0 million shares of common stock, plus the addition of any shares subject to outstanding awards under the 2006 Equity Incentive Plan and the Amended and Restated 1996 Stock Plan that were outstanding as of May 19, 2015, and that subsequently expire or otherwise terminate, up to a maximum of an additional 29.0 million shares. In May 2017, the Company's stockholders approved an additional 23.0 million shares of common stock for issuance under the 2015 Plan, and in May 2019, the Company's stockholders approved an additional 3.7 million shares of common stock for issuance under the 2015 Plan. As of December 31, 2021, an aggregate of 16.5 million shares were subject to outstanding equity awards and 5.1 million shares were available for future issuance under the 2015 Plan. The ESPP was adopted and approved by the Company's stockholders in May 2008. In May 2020, the Company's stockholders approved an additional 8.0 million shares of common stock for issuance under the ESPP. To date, the Company's stockholders have approved a share reserve of 43.0 million shares of the Company's common stock for issuance under the ESPP. The ESPP permits eligible employees to acquire shares of the Company’s common stock at a 15% discount (as determined in the ESPP) through periodic payroll deductions of up to 10% of base compensation, subject to individual purchase limits of 6,000 shares in any twelve-month period or $25,000 worth of stock, determined at the fair market value of the shares at the time the stock purchase option is granted, in one In 2021, in connection with the acquisitions of Apstra and WiteSand, the Company assumed an aggregate of 2.5 million shares of stock options, RSUs, RSAs, and PSAs. In 2020, in connection with the acquisition of 128 Technology, the Company assumed an aggregate of 3.9 million shares of stock options, RSUs, RSAs, and PSAs. No additional awards can be granted under the stock plans of the acquired companies. As of December 31, 2021, approximately 5.8 million shares of common stock were outstanding under all awards assumed or substituted through the Company's acquisitions. RSU, RSA, and PSA Activities RSUs generally vest over three years from the date of grant, and RSAs and PSAs generally vest over a period of two The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the year ended December 31, 2021 (in millions, except per share amounts and years): Outstanding RSUs, RSAs, and PSAs Number of Shares Weighted Average Weighted Average Aggregate Balance at December 31, 2020 19.9 $ 23.05 Granted (1)(2) 10.2 26.19 Awards assumed upon the acquisitions of Apstra and WiteSand (2) 2.5 26.28 Vested (3) (7.8) 23.66 Canceled (2.6) 23.91 Balance at December 31, 2021 22.2 $ 24.55 1.3 $ 791.3 As of December 31, 2021 Vested and expected-to-vest RSUs, RSAs, and PSAs 19.7 $ 24.96 1.3 $ 703.7 ________________________________ (1) Includes 8.2 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. (2) The weighted-average grant-date fair value of RSUs, RSAs, and PSAs granted and assumed or substituted during 2021, 2020, and 2019 was $26.21, $21.59, and $25.26, respectively. 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. During 2021, the Company declared a quarterly cash dividend of $0.20 per share of common stock on January 28, 2021, April 27, 2021, July 27, 2021 and October 26, 2021. (3) Total fair value of RSUs, RSAs, and PSAs vested during 2021, 2020, and 2019 was $184.2 million, $174.7 million, and $170.0 million, respectively. Shares Available for Grant The following table presents the stock activity and the total number of shares available for grant under the 2015 Plan (in millions): Number of Shares Balance as of December 31, 2020 12.1 Additional shares authorized — RSUs and PSAs granted () (10.5) RSUs and PSAs canceled () 3.5 Balance as of December 31, 2021 5.1 ________________________________ (*) In May 2019, the 2015 Plan was amended, and the amendment removed the fungible share adjustment used to determine shares available for issuance. Under the original terms of the 2015 Plan, RSUs and PSAs with a per share or unit purchase price lower than 100% of the fair market value of the Company's common stock on the day of the grant were counted against shares authorized under the plan as two and one-tenth shares of common stock ("the prior fungible rate") for each share subject to such award. Pursuant to the amendment, beginning on May 14, 2019, each share award granted under the 2015 Plan reduces the share reserve by one share and all share awards granted on May 14, 2019 and thereafter that are later forfeited, canceled or terminated are returned to the share reserve in the same manner. During 2021, among the total 3.5 million of canceled shares, 2.2 million shares represent the shares returned to the share reserve at the prior fungible rate. The number of shares subject to PSAs granted represents the maximum number of shares that may be issued pursuant to the award over its full term. Employee Stock Purchase Plan During 2021, 2020, and 2019, employees purchased 2.8 million, 2.7 million and 2.4 million shares of common stock through the ESPP at an average exercise price of $19.81, $19.59, and $22.04 per share, respectively. Valuation Assumptions The weighted-average assumptions used and the resulting estimates of fair value for ESPP purchase rights and market-based RSUs were as follows: Years Ended December 31, 2021 2020 2019 ESPP Purchase Rights: Volatility 32% 31% 27% Risk-free interest rate 0.1% 0.8% 2.1% Expected life (years) 1.3 1.3 1.2 Dividend yield 3.0% 3.3% 2.9% Weighted-average fair value per share $6.96 $6.34 $6.65 Market-based RSUs: Volatility 30% 25% 25% Risk-free interest rate 0.2% 1.3% 2.4% Dividend yield 3.4% 3.3% 2.8% Weighted-average fair value per share $30.70 $26.32 $27.32 Share-Based Compensation Expense Share-based compensation expense associated with stock options, RSUs, RSAs, PSAs, and ESPP purchase rights was recorded in the following cost and expense categories in the Company's Consolidated Statements of Operations (in millions): Years Ended December 31, 2021 2020 2019 Cost of revenues - Product $ 5.3 $ 5.4 $ 5.7 Cost of revenues - Service 18.2 15.8 17.3 Research and development 93.1 78.8 94.0 Sales and marketing 65.9 58.2 56.0 General and administrative 40.1 31.4 29.2 Total $ 222.6 $ 189.6 $ 202.2 The following table summarizes share-based compensation expense by award type (in millions): Years Ended December 31, 2021 2020 2019 Stock options $ 9.3 $ 7.3 $ 7.7 RSUs, RSAs, and PSAs 196.2 162.6 176.5 ESPP Purchase Rights 17.1 19.7 18.0 Total $ 222.6 $ 189.6 $ 202.2 For the years ended December 31, 2021, 2020 and 2019, the Company recognized tax benefits on total stock-based compensation expense, which are reflected in the income tax provision in the Consolidated Statements of Operations, of $28.2 million, $23.5 million, and $29.6 million, respectively. For the years ended December 31, 2021, 2020, and 2019, the realized tax benefit related to awards vested or exercised during the period was $31.7 million, $21.7 million and $30.6 million, respectively. These amounts do not include the indirect effects of stock-based awards, which primarily relate to the research and development tax credit. As of December 31, 2021, the total unrecognized compensation cost related to unvested share-based awards was $357.4 million to be recognized over a weighted-average period of 1.8 years. 401(k) Plan The Company maintains a savings and retirement plan qualified under Section 401(k) of the Internal Revenue Code of 1986, as amended (the "IRC"). Employees meeting the eligibility requirements, as defined under the IRC, may contribute up to the statutory limits each year. The Company currently matches 30% of all eligible employee contributions which vest immediately. The Company’s matching contributions to the plan totaled $22.3 million, $22.0 million, and $20.2 million during 2021, 2020, and 2019, respectively. Deferred Compensation Plan The Company’s NQDC plan is an unfunded and unsecured deferred compensation arrangement. Under the NQDC plan, officers and other senior employees may elect to defer a portion of their compensation and contribute such amounts to one or more investment funds. As of December 31, 2021, the liability of the Company to the plan participants was $33.3 million, of which $4.4 million was included within other accrued liabilities and $28.9 million was included in other long-term liabilities on the Consolidated Balance Sheets. The Company had investments of $33.3 million correlating to the deferred compensation obligations, of which $4.4 million was included within prepaid expenses and other current assets and $28.9 million was included within other long-term assets on the Consolidated Balance Sheets. As of December 31, 2020, the liability of the Company was $29.3 million, of which $3.1 million was included within other accrued liabilities and $26.2 million was included in other long-term liabilities on the Consolidated Balance Sheets. The Company had investments of $29.3 million correlating to

Segments

Segments	12 Months Ended
Segments	Dec. 31, 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 year 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 year 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): Years Ended December 31, 2021 2020 2019 Customer Solutions: Automated WAN Solutions $ 1,665.0 $ 1,622.2 $ 1,604.4 Cloud-Ready Data Center 727.1 677.1 726.5 AI-Driven Enterprise 830.4 656.2 613.8 Hardware Maintenance and Professional Services 1,512.9 1,489.6 1,500.7 Total $ 4,735.4 $ 4,445.1 $ 4,445.4 The following table presents net revenues by customer vertical (in millions): Years Ended December 31, 2021 2020 2019 Cloud $ 1,228.0 $ 1,081.2 $ 1,059.8 Service Provider 1,839.1 1,761.7 1,827.8 Enterprise 1,668.3 1,602.2 1,557.8 Total $ 4,735.4 $ 4,445.1 $ 4,445.4 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): Years Ended December 31, 2021 2020 2019 Americas: United States $ 2,426.9 $ 2,233.9 $ 2,299.8 Other 222.2 211.2 218.2 Total Americas 2,649.1 2,445.1 2,518.0 Europe, Middle East, and Africa 1,314.5 1,233.8 1,215.3 Asia Pacific 771.8 766.2 712.1 Total $ 4,735.4 $ 4,445.1 $ 4,445.4 During the years ended December 31, 2021, 2020, and 2019, no customer accounted for greater than 10% of the Company's net revenues. The following table presents geographic information for property and equipment, net (in millions). As of December 31, 2021 2020 United States $ 623.4 $ 667.4 International 79.6 94.9 Property and equipment, net $ 703.0 $ 762.3 The Company tracks assets by physical location. The majority of the Company’s assets, excluding cash and cash equivalents and investments, as of December 31, 2021 and December 31, 2020, were attributable to U.S. operations.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 13. Income Taxes The components of pretax income are summarized as follows (in millions): Years Ended December 31, 2021 2020 2019 Domestic $ 264.6 $ 204.2 $ 296.2 Foreign 45.5 61.0 118.2 Total pretax income $ 310.1 $ 265.2 $ 414.4 The provision (benefit) for income taxes is summarized as follows (in millions): Years Ended December 31, 2021 2020 2019 Current provision (benefit): Federal $ 63.4 $ 73.4 $ 6.2 States 15.9 20.3 14.4 Foreign 48.2 (21.6) 48.5 Total current provision (benefit) 127.5 72.1 69.1 Deferred (benefit) provision: Federal (54.3) (58.7) 0.8 States (4.1) (6.6) 2.8 Foreign (11.7) 0.6 (3.3) Total deferred (benefit) provision (70.1) (64.7) 0.3 Total provision (benefit) for income taxes $ 57.4 $ 7.4 $ 69.4 The provision (benefit) for income taxes differs from the amount computed by applying the federal statutory tax rate of 21% to pretax income for each of the years presented as follows (in millions): Years Ended December 31, 2021 2020 2019 Expected provision at statutory rate $ 65.1 $ 55.7 $ 87.0 State taxes, net of federal benefit 6.5 8.7 9.4 Foreign income at different tax rates (0.2) (5.9) 1.8 R&D tax credits (16.6) (16.4) (18.8) Share-based compensation (2.2) 9.0 3.8 Non-deductible compensation 4.2 3.5 3.3 Temporary differences not currently benefited — (0.9) 12.9 Recognition of previously unrecognized tax benefits — (63.7) (25.4) Cost sharing adjustment- Altera — 20.1 — Lapses in federal statutes of limitations — — (7.5) Other 0.6 (2.7) 2.9 Total provision (benefit) for income taxes $ 57.4 $ 7.4 $ 69.4 In 2020, the Company recorded a $63.7 million benefit, including interest and penalties, related to a multi-year recognition of previously unrecognized tax benefits and a $20.1 million charge, including interest, for a cumulative impact of cost sharing for share-based compensation described below. On June 7, 2019, the Ninth Circuit Court of Appeals issued an opinion in Altera Corp. v. Commissioner requiring related parties in an intercompany cost-sharing arrangement to share expenses related to share-based compensation. On February 10, 2020, Altera appealed this decision to the U.S. Supreme Court, which on June 22, 2020, declined to review the decision. Based on the Supreme Court's decision, the Company's share-based compensation is subject to cost sharing, and the Company recorded a $20.1 million charge referenced above during the year ended December 31, 2020. Deferred income taxes reflect the net tax effects of tax carry-forward items and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company's long-term deferred tax assets and deferred tax liabilities are as follows (in millions): As of December 31, 2021 2020 Deferred tax assets: Net operating loss carry-forwards $ 72.5 $ 48.2 Research and other credit carry-forwards 272.2 252.8 Deferred revenue 47.7 43.4 Share-based compensation 17.9 15.0 Capitalized R&D expenditure 102.0 60.5 Reserves and accruals not currently deductible 61.0 43.5 Operating lease liabilities 45.4 51.3 Other 9.9 10.6 Total deferred tax assets 628.6 525.3 Valuation allowance (300.9) (261.5) Deferred tax assets, net of valuation allowance 327.7 263.8 Deferred tax liabilities: Property and equipment basis differences (1.3) (20.1) Purchased intangible assets (56.5) (45.6) Unremitted foreign earnings (25.5) (25.5) Net unrealized gain (21.0) (21.1) Operating lease assets (39.9) (44.9) Total deferred tax liabilities (144.2) (157.2) Net deferred tax assets $ 183.5 $ 106.6 As of December 31, 2021 and 2020, the Company had a valuation allowance on its U.S. and foreign deferred tax assets of $300.9 million and $261.5 million, respectively. The balance at December 31, 2021 consisted of $2.0 million , $288.7 million and $10.2 million against the Company's U.S. federal, state, and foreign deferred tax assets, respectively, which the Company believes are not more likely than not to be utilized in future years. The valuation allowance increased in 2021 and 2020 by $39.4 million and $12.1 million, respectively, primarily related to the changes in state R&D tax credits. As of December 31, 2021, the Company had federal, California and other states net operating loss carry-forwards of approximately $205.5 million, $197.9 million and $144.6 million, respectively. The California net operating loss carry-forwards of $197.9 million are expected to expire unused. The Company also had federal and California tax credit carry-forwards of approximately $6.6 million and $292.4 million, respectively. Unused net operating loss carry-forwards will expire at various dates beginning in the year 2022. The California tax credit carry-forwards will carry forward indefinitely. The Company provides deferred tax liabilities for all tax consequences associated with the undistributed earnings that are expected to be repatriated to subsidiaries' parent unless the subsidiaries' earnings are considered indefinitely reinvested. The Company has made no provision for deferred taxes on approximately $83.1 million of cumulative undistributed earnings of certain foreign subsidiaries through December 31, 2021. These earnings are considered indefinitely invested in operations of the subsidiaries, as the Company intends to utilize these amounts to fund future expansion of its operations. If these earnings were distributed to the parent, the Company would be subject to additional taxes of approximately $16.9 million. As of December 31, 2021, 2020, and 2019, the total amount of gross unrecognized tax benefits was $113.4 million, $116.0 million, and $151.3 million, respectively. As of December 31, 2021, approximately $110.5 million of the $113.4 million gross unrecognized tax benefits, if recognized, would affect the effective tax rate before considering valuation allowance. A reconciliation of the beginning and ending amount of the Company's total gross unrecognized tax benefits was as follows (in millions): Years Ended December 31, 2021 2020 2019 Balance at beginning of year $ 116.0 $ 151.3 $ 178.1 Tax positions related to current year: Additions 7.7 5.3 5.9 Tax positions related to prior years: Additions 3.3 18.1 0.8 Reductions (3.6) (52.0) (3.3) Settlements (9.4) (1.8) (22.5) Lapses in statutes of limitations (0.6) (4.9) (7.7) Balance at end of year $ 113.4 $ 116.0 $ 151.3 As of December 31, 2021, 2020, and 2019, the Company had accrued interest and penalties related to unrecognized tax benefits of $8.1 million, $5.3 million, and $29.9 million, respectively, as other long-term liabilities in the Consolidated Balance Sheets. Due to the changes in the level of gross unrecognized tax benefits, the Company recognized a benefit for net interest and penalties of $2.7 million, $20.7 million and $2.8 million in its Consolidated Statements of Operations during the years ended December 31, 2021, 2020, and 2019, respectively. The Company recognizes interest and penalties related to unrecognized tax benefits as a component of income tax expense. 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 $7.3 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 conducts business globally and, as a result, Juniper Networks or one or more of its subsidiaries files income tax returns in the U.S. federal jurisdiction and various state and foreign jurisdictions. In the normal course of business, the Company is subject to examination by taxing authorities throughout the world, including such major jurisdictions as the Netherlands, U.K., France, Germany, Japan, China, Australia, India, and the U.S. With few exceptions, the Company is no longer subject to U.S. federal, state and local, and non-U.S. income tax examinations for years before 2012. 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 2012 through 2017 tax years, respectively. The Company regularly assesses the likelihood of an adverse outcome resulting from such examinations. As of December 31, 2021, the Company believes the resolution of the audits is unlikely to have a material effect on its consolidated financial condition or results of operations. The Company is pursuing all available administrative remedies relative to these ongoing matters. The Company believes that it has adequately provided for any reasonably foreseeable outcomes related to these proposed adjustments and the ultimate resolution of these matters is unlikely to have a material effect on its consolidated financial condition or results of operations; however, there is still a possibility that an adverse outcome of these matters could have a material effect on its consolidated financial condition and results of operations.

Net Income Per Share

Net Income Per Share	12 Months Ended
Net Income Per Share	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Income per Share	Note 14. Net Income per Share The Company computed basic and diluted net income per share as follows (in millions, except per share amounts): Years Ended December 31, 2021 2020 2019 Numerator: Net income $ 252.7 $ 257.8 $ 345.0 Denominator: Weighted-average shares used to compute basic net income per share 324.4 330.4 343.2 Dilutive effect of employee stock awards 7.2 4.8 5.0 Weighted-average shares used to compute diluted net income per share 331.6 335.2 348.2 Net income per share: Basic $ 0.78 $ 0.78 $ 1.01 Diluted $ 0.76 $ 0.77 $ 0.99 Anti-dilutive shares 0.5 5.3 4.7 Basic net income per share is computed using net income available to common stockholders and the weighted-average number of common shares outstanding for the period. Diluted net income per share is computed using net income available to common stockholders and the weighted-average number of common shares outstanding plus potentially dilutive common shares outstanding during the period. Dilutive potential common shares consist of common shares issuable upon exercise of stock options and purchase rights, and vesting of RSUs, RSAs, and PSAs. The Company includes the common shares underlying PSAs in the calculation of diluted net income per share only when they become contingently issuable. Anti-dilutive shares are excluded from the computation of diluted net income per share.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 15. Commitments and Contingencies Commitments Unconditional Purchase Obligations Unconditional purchase obligations consist of agreements that include firm and non-cancelable terms to transfer funds in the future for fixed or minimum amounts or quantities to be purchased at fixed or minimum prices. For obligations with cancellation provisions, the amounts included in the following table were limited to the non-cancelable portion of the agreement terms or the minimum cancellation fee. The following table summarizes the Company’s unconditional purchase obligations as of December 31, 2021 (in millions): Years Ending December 31, Unconditional Purchase Obligations 2022 $ 61.0 2023 43.9 2024 16.5 2025 7.3 2026 0.6 Total $ 129.3 In December 2018, the Company entered into a Master Services Agreement and certain Statements of Work, as subsequently amended (collectively, the “Agreement”) with International Business Machines Corporation ("IBM"). As of December 31, 2021, the Company expects to pay IBM $145.3 million over the remaining initial term of the Agreement. The table above does not include fees payable to IBM under the contract as the Company is unable to make a reasonably reliable estimate of the amount of the payments related to each of the years under this contract due to uncertainties in the usage of the services. Leases The Company leases its facilities and certain equipment under non-cancelable operating leases that have remaining lease terms of 1 to 10 years and 1 to 4 years, respectively. Each leased facility is subject to an individual lease or sublease, which could provide various options to extend or terminate the lease agreement. Facilities are primarily comprised of corporate offices, data centers, and R&D facilities. Equipment includes vehicles and various office equipment. The Company also has variable lease payments that are primarily comprised of common area maintenance and utility charges. The Company's lease agreements do not contain any residual value guarantees or restrictive covenants. The components of lease costs and other information related to leases were as follows (in millions, except years and percentages): Years Ended December 31, 2021 2020 Operating lease cost $ 57.4 $ 50.8 Variable lease cost 11.5 13.4 Total lease cost $ 68.9 $ 64.2 Operating cash outflows from operating leases $ 57.8 $ 54.2 ROU assets obtained in exchange for new operating lease liabilities $ 29.7 $ 54.7 As of December 31, 2021 2020 Weighted average remaining lease term (years) 4.6 4.9 Weighted average discount rate 3.3 % 3.7 % As of December 31, 2021, future operating lease payments for each of the next five years and thereafter are as follows (in millions): Years Ending December 31, Amount 2022 $ 48.7 2023 47.6 2024 43.1 2025 34.6 2026 14.3 Thereafter 15.3 Total lease payments 203.6 Less: interest (14.2) Total $ 189.4 Balance Sheet Information Other accrued liabilities $ 47.2 Long-term operating lease liabilities 142.2 Total $ 189.4 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. The following table summarizes the Company’s purchase commitments as of December 31, 2021 (in millions): Years Ending December 31, Purchase Commitments 2022 $ 2,094.3 2023 523.0 2024 14.4 2025 0.5 Total $ 2,632.2 The Company establishes a liability in connection with purchase commitments related to quantities in excess of its demand forecasts or obsolete materials charges for components purchased by the contract manufacturers based on the Company’s demand forecast or customer orders. As of December 31, 2021, the Company had accrued $19.8 million based on its estimate of such charges. Debt and Interest Payment on Debt As of December 31, 2021, the Company held total outstanding debt consisting of the Notes with a carrying value of $1,686.8 million . See Note 9, Debt and Financing , for further discussion of the Company's long-term debt and expected future principal maturities. Tax Liability Our transition tax liability represents future cash payments on accumulated foreign earnings of subsidiaries as a result of the Tax Cuts and Jobs Act of 2017 ("Tax Act"). The Company has elected to pay its transition tax, net of applicable tax refunds, over the eight-year period provided in the Tax Act. The long-term income taxes payable of $250.6 million represents the remaining balance of the Company's transition tax obligation. As of December 31, 2021, the Company had $79.9 million included in long-term income taxes payable on the Consolidated Balance Sheets for unrecognized tax positions. At this time, the Company is unable to make a reasonably reliable estimate of the timing of payments related to this amount due to uncertainties in the timing of tax audit outcomes. Guarantees The Company enters into agreements with customers that contain indemnification provisions relating to potential situations where claims could be alleged that the Company’s products solely, or in combination with other third-party products, infringe the intellectual property rights of a third-party. As of December 31, 2021 and 2020, the Company recorded $1.9 million and $6.7 million, respectively, for such indemnification obligations in other accrued liabilities and other long-term liabilities on the Consolidated Balance Sheets. The Company also has financial guarantees consisting of standby letters of credit for certain lease facilities, insurance programs and customs o f $2.4 million and $29.0 million, as of December 31, 2021 and December 31, 2020, respectively. Legal Proceedings The Company is involved in investigations, disputes, litigation, 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 these matters, and while there can be no assurances and the outcome of these matters is currently not determinable, the Company currently believes that these existing claims or proceedings are not likely, individually and in the aggregate, 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 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 those 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

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 16. Subsequent Events Dividend Declaration On January 27, 2022, the Company announced a cash dividend of $0.21 per share of common stock to be paid on March 22, 2022 to stockholders of record as of the close of business on March 1, 2022. Stock Repurchase Activities Subsequent to December 31, 2021, through the date of filing of this Report (the "filing date"), the Company repurchased 2.6 million shares of its common stock in the open market, for an aggregate purchase price of $91.1 million at an average price of $34.75 per share, under the 2018 Stock Repurchase Program. Repurchases of approximately 2.0 million shares were settled prior to the filing of this Report and the remaining shares will be settled after the filing date. The Company has an aggregate of $0.8 billion of authorized funds remaining under the 2018 Stock Repurchase Program as of the filing date.

Schedule II- Valuation and Qual

Schedule II- Valuation and Qualifying Account	12 Months Ended
Schedule II- Valuation and Qualifying Account	Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Account	Juniper Networks, Inc. Schedule II - Valuation and Qualifying Accounts Years Ended December 31, 2021, 2020, and 2019 (In millions) Allowance for Doubtful Accounts Balance at Charged to Write-offs, Balance at 2021 $ 9.9 $ (3.2) $ — $ 6.7 2020 $ 5.5 $ 4.4 $ — $ 9.9 2019 $ 4.9 $ 1.7 $ (1.1) $ 5.5 Sales Return Reserve Balance at Charged as a Used Balance at 2021 $ 28.4 $ 57.6 $ (54.6) $ 31.4 2020 $ 24.8 $ 60.7 $ (57.1) $ 28.4 2019 $ 32.7 $ 59.5 $ (67.4) $ 24.8 All other schedules have been omitted as the required information is not applicable or the information is presented in the Consolidated Financial Statements or notes thereto under Item 8 herein.

Description of Business, Basi_2

Description of Business, Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Consolidated Financial Statements, which include the Company and its wholly-owned subsidiaries, are prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). All intercompany balances and transactions have been eliminated. Certain reclassifications have been made to the amounts for the prior year in order to conform to the current year's presentation.
Use of Estimates	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 Consolidated Financial Statements and the accompanying notes. The Company bases its estimates and assumptions on current facts, historical experience, and various other factors that it believes are reasonable under the circumstances, to determine the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from these estimates.
Cash, Cash Equivalents, and Investments	Cash, Cash Equivalents, and Investments Cash and Cash Equivalents Cash and cash equivalents consist of cash on hand, demand deposits with banks, highly liquid investments in money market funds, commercial paper, government securities, certificates of deposits, time deposits, and corporate debt securities, which are readily convertible into cash. All highly liquid investments with original maturities of three months or less from Juniper's purchase date are classified as cash equivalents.
Investments in Available-for-Sale Debt Securities and Equity Securities	Investments in Available-for-Sale Debt Securities The Company's investments in debt securities are classified as available-for-sale and include the Company's fixed income securities and investments in privately-held companies, consisting of debt and redeemable preferred stock securities. Fixed income securities primarily consist of corporate debt securities, U.S. treasury securities, time deposits, asset-backed and mortgage-backed securities, certificate of deposits, commercial paper, U.S. government agency securities, and foreign government debt securities. Fixed income securities are initially recorded at cost and periodically adjusted to fair value in the Consolidated Balance Sheets. The Company periodically evaluates these investments to determine if impairment charges are required. The Company determines whether a credit loss exists for available-for-sale debt securities in an unrealized loss position. When the fair value of a security is below its amortized cost, the amortized cost will be reduced to its fair value and the resulting loss will be recorded in Consolidated Statements of Operations, if it is more likely than not that we are required to sell the impaired security before recovery of its amortized cost basis, or we have the intention to sell the security. If neither of these conditions are met, the Company considers the extent to which the fair value is less than the amortized cost, any changes to the rating of the security by a rating agency, and review of the issuer's financial statements. If factors indicate a credit loss exists, an allowance for credit loss is recorded through other expense, net, limited by the amount that the fair value is less than the amortized cost basis. The Company's privately-held debt and redeemable preferred stock securities are included in other long-term assets in the Consolidated Balance Sheets and are recorded at fair value. Fair value is reassessed when the Company is made aware of information indicating a change in the enterprise value of the investee, including known acquisition offers, subsequent funding rounds, and investee's plans for liquidation. The Company periodically evaluates these securities for indicators of impairment, including the inability to recover a portion of or the entire carrying amount of the investment, the inability of the investee to sustain earnings, the reduction in or termination of financial commitment to the investee from other investors, the intention to sell the investment, and whether it is more likely than not that the Company will be required to sell the investment before recovery of the entire amortized cost basis. If the Company determines that the decline in an investment's value indicates credit losses, the difference is recognized as an impairment loss in its Consolidated Statements of Operations. For all available-for-sale debt securities, unrealized gains and the amount of unrealized loss relating to factors other than credit loss are reported as a separate component of accumulated other comprehensive loss in the Consolidated Balance Sheets. Realized gains and losses are determined based on the specific identification method and are reported in the Consolidated Statements of Operations. Investments in Equity Securities The Company's investments in equity securities with readily determinable fair values consist of money market funds, amounts under the non-qualified compensation plan ("NQDC") that are invested in mutual funds, and investments in public companies. These investments are measured at fair value with changes in fair value recognized in the Consolidated Statements of Operations.
Fair Value	Fair Value Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which it transacts, and considers assumptions that market participants would use when pricing the asset or liability. The Company applies the following fair value hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1 – Quoted prices in active markets for identical assets or liabilities. Level 2 – Quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. These inputs are valued using market-based approaches. Level 3 – Inputs are unobservable inputs based on the Company’s assumptions. These inputs, if any, are valued using internal financial models.
Derivative Instruments	Derivative Instruments The Company uses derivative instruments, primarily foreign currency forward and interest rate contracts, to hedge certain foreign currency and interest rate exposures. The Company does not enter into derivatives for speculative or trading purposes. The Company uses foreign currency forward contracts to hedge certain forecasted foreign currency transactions relating to operating expenses. These derivatives are designated as cash flow hedges, which are carried at fair value with the derivative's gain or loss initially reported as a component of accumulated other comprehensive loss, and upon occurrence of the forecasted transaction, is subsequently reclassified into the costs of services or operating expense line item to which the hedged transaction relates. Cash flows from such hedges are classified as operating activities. The Company also uses foreign currency forward contracts to mitigate variability in gains and losses generated from the re-measurement of certain monetary assets and liabilities denominated in non-functional currencies. These derivatives are carried at fair value with changes recorded in other expense, net in the Consolidated Statements of Operations in the same period as the changes in the fair value from the re-measurement of the underlying assets and liabilities. Cash flows from such derivatives are classified as operating activities. The Company uses interest rate swaps to convert certain of our fixed interest rate notes to floating interest rates based on the London InterBank Offered Rate (LIBOR). All interest rate swaps will expire within nine years. The change in fair value of the derivative instrument substantially offsets the change in the fair value of the hedged item. These derivatives are classified in the Consolidated Statements of Cash Flows in the same section as the underlying item. The Company uses interest rate locks, which fix the benchmark interest rates of future debt issuance. The Company records changes in fair value of interest rate locks in accumulated other comprehensive income (loss) in the consolidated balance sheets, in the period of change. When the forecasted transaction occurs, the Company will start to amortize the accumulated gains or losses included as a component of other comprehensive income (loss) related to the interest rate lock cash flow hedges to interest expense. In the event the underlying forecasted transaction does not occur, or it becomes probable that it will not occur, the gains or losses on the related cash flow hedge from accumulated other comprehensive income (loss) will be reclassified to other income and expense within the income statement. The Company presents its derivative assets and derivative liabilities on a gross basis in the Consolidated Balance Sheets. However, under agreements containing provisions on set-off with certain counterparties, subject to applicable requirements, the Company is allowed to net-settle transactions, with a single net amount payable by one party to the other. The Company is neither required to pledge nor entitled to receive cash collateral related to these derivative transactions.
Inventory	Inventory Inventory consists primarily of component parts to be used in the manufacturing process and finished goods, and is stated at the lower of cost or net realizable value. In addition, the Company purchases and holds inventory to provide adequate component supplies over the life of the underlying products. Cost is computed using standard cost, which approximates actual cost, on a first-in, first-out basis. A charge is recorded to cost of product when inventory is determined to be in excess of anticipated demand or considered obsolete. At the point of loss recognition, a new, lower-cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in the newly established cost basis.
Leases	Leases The Company determines if an arrangement is a lease at inception. The Company evaluates classification of leases as either operating or finance at commencement and, as necessary, at modification. As of December 31, 2021, the Company did not have any finance leases. Operating leases are included in operating lease right-of-use ("ROU") assets, other accrued liabilities, and operating lease liabilities on the Company's Consolidated Balance Sheets. ROU assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized on the commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made prior to lease commencement and excludes lease incentives. Variable lease payments not dependent on an index or a rate, are expensed as incurred and are not included within the ROU asset and lease liability calculation. Variable lease payments primarily include reimbursements of costs incurred by lessors for common area maintenance and utilities. The Company's lease terms are the noncancelable period, including any rent-free periods provided by the lessor, and include options to extend or terminate the lease when it is reasonably certain that it will exercise that option. At lease inception, and in subsequent periods as necessary, the Company estimates the lease term based on its assessment of extension and termination options that are reasonably certain to be exercised. Lease costs are recognized on a straight-line basis over the lease term. The Company does not separate non-lease components from lease components for all underlying classes of assets. In addition, the Company does not recognize ROU assets and lease liabilities for short-term leases, which have a lease term of twelve months or less and do not include an option to purchase the underlying asset that the Company is reasonably certain to exercise. Lease cost for short-term leases is recognized on a straight-line basis over the lease term.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method, over the estimated useful lives of the following assets: Estimated Useful Life (years) Computers, equipment, and software 1.5 to 10 Furniture and fixtures 5 to 7 Building and building improvements 7 to 40 Land improvements 10 to 40 Leasehold improvements Lease term, not to exceed 10 years
Business Combinations	Business Combinations The purchase price of an acquired entity is allocated to tangible assets, liabilities, and intangible assets, including in-process research and development (IPR&D) based on their estimated fair values with the residual of the purchase price recorded as goodwill. The determination of the value of the intangible assets acquired involves certain estimates, such as expected future cash flows, which include consideration of future growth rates and margins, attrition rates, future changes in technology, discount rates, and the expected use of the acquired assets. These factors are also considered in determining the useful life of the acquired intangible assets. IPR&D is initially capitalized at fair value as an intangible asset with an indefinite life and assessed for impairment thereafter. When an IPR&D project is completed, the IPR&D is reclassed as an amortizable purchased intangible asset and amortized over the asset’s estimated useful life. Acquisition related expenses are recognized separately from business combination and are expensed as incurred. The Company's Consolidated Financial Statements include the operating results of acquired businesses from the date of each acquisition.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill is tested for impairment annually on November 1 or more frequently if certain circumstances indicate the carrying value of goodwill is impaired. Goodwill is tested for impairment at the reporting unit level. A qualitative assessment is first performed to determine whether it is necessary to quantitatively test goodwill for impairment. This initial assessment includes, among others, consideration of macroeconomic conditions and financial performance. If the qualitative assessment indicates that it is more likely than not that an impairment exists, a quantitative analysis is performed by determining the fair value of the reporting unit using a combination of the discounted cash flow and the market approaches. Goodwill is considered impaired if the carrying value of the reporting unit exceeds its fair value. A goodwill impairment loss is recognized for the amount that the carrying amount of the reporting unit, including goodwill, exceeds its fair value, limited to the total amount of goodwill allocated to that reporting unit. Intangible assets consist of existing technology, customer relationships, and trade name, which are amortized over the period of estimated benefit using the straight-line method and estimated useful lives of 4 or 5 years. Other intangible assets acquired in a business combination related to IPR&D projects are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts. Indefinite-lived intangibles are not amortized into the results of operations but instead are evaluated for impairment. If and when development is complete, the associated assets would be deemed finite-lived
Impairment of Long-lived Assets	Impairment of Long-lived Assets Long-lived assets, such as property, plant, and equipment, ROU assets, and purchased intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset, or asset group, to estimated undiscounted future cash flows expected to be generated by the asset, or asset group. An impairment charge is recognized by the amount by which the carrying amount of the asset, or asset group, exceeds its fair value.
Warranty Reserves	Warranty Reserves The Company generally offers a one-year warranty or limited life-time warranty on most of its hardware products, and a 90-day warranty on the media that contains the software embedded in the products. Warranty costs are recognized as part of the Company's cost of sales based on associated material costs, logistics costs, labor costs, and overhead at the time revenue is recognized. Material costs are estimated primarily based upon the historical costs to repair or replace product returns within the warranty period. Labor, logistics and overhead costs are estimated primarily based upon historical trends in the cost to support customer cases within the warranty period. Warranty reserve is reported within other accrued liabilities in the Consolidated Balance Sheets.
Contract Manufacturer Liabilities	Contract Manufacturer LiabilitiesThe Company establishes a liability for non-cancelable, non-returnable purchase commitments with its contract manufacturers for carrying charges, quantities in excess of its demand forecasts, or obsolete material charges for components purchased by the contract manufacturers to meet the Company’s demand forecast or customer orders. The demand forecasts are based upon historical trends and analysis from the Company's sales and marketing organizations, adjusted for overall market conditions.
Loss Contingencies	Loss ContingenciesThe Company is subject to the possibility of various loss contingencies arising in the ordinary course of business. Management considers the likelihood of loss related to the incurrence of a liability as well as its ability to reasonably estimate the amount of loss, in determining loss contingencies. An estimated loss contingency is accrued when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information available to determine whether such accruals should be adjusted and whether new accruals are required.
Foreign Currency	Foreign Currency Assets and liabilities of foreign operations with non-U.S. Dollar functional currency are translated to U.S. Dollars using exchange rates in effect at the end of the period. Revenue and expenses are translated to U.S. Dollars using rates that approximate those in effect during the period. The resulting translation adjustments are included in the Company’s Consolidated Balance Sheets in the stockholders’ equity section as a component of accumulated other comprehensive loss. The Company remeasures monetary assets and monetary liabilities in non-functional currencies and records the resulting foreign exchange transaction gains and losses in other expense, net in the Consolidated Statements of Operations.
Revenue Recognition	Revenue Recognition Revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services by following a five-step process, (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price, and (5) recognize revenue when or as the Company satisfies a performance obligation, as further described below. Identify the contract with a customer . The Company generally considers a sales contract and/or agreement with an approved purchase order as a customer contract provided that collection is considered probable, which is assessed based on the creditworthiness of the customer as determined by credit checks, payment histories, and/or other circumstances. The Company combines contracts with a customer if contracts are negotiated with a single commercial substance or contain price dependencies. Identify the performance obligations in the contract . Product performance obligations include hardware, software licenses, and service performance obligations including hardware maintenance, software post-contract support and maintenance, Software-as-a-Service ("SaaS"), education and training, and professional services. Certain software licenses and related post-contract support are combined into a single performance obligation when the maintenance updates are critical to the continued delivery of the software functionality. Determine the transaction price . The transaction price for the Company’s contracts with its customers consists of both fixed and variable consideration provided it is probable that a significant reversal of revenue will not occur when the uncertainty related to variable consideration is resolved. Fixed consideration includes amounts to be contractually billed to the customer while variable consideration includes estimates for rights of return, rebates, and price protection, which are based on historical sales returns and price protection credits, specific criteria outlined in rebate agreements, and other factors known at the time. The Company generally invoices customers for hardware, software licenses and related maintenance arrangements at time of delivery, and professional services either upfront or upon meeting certain milestones. Customer invoices are generally due within 30 to 90 days after issuance. The Company’s contracts with customers typically do not include significant financing components as the period between the transfer of performance obligations and timing of payment are generally within one year. Allocate the transaction price to the performance obligations in the contract . For contracts that contain multiple performance obligations, the Company allocates the transaction price to the performance obligations on a relative stand-alone selling price ("SSP") basis. SSP is based on multiple factors including, but not limited to historical discounting trends for products and services, pricing practices in different geographies and through different sales channels, gross margin objectives, internal costs, competitor pricing strategies, and industry technology lifecycles. Recognize revenue when or as the Company satisfies a performance obligation . Revenue for hardware and certain software licenses, are recognized at a point in time, which is generally upon shipment or delivery. Certain software licenses combined with post-contract support and maintenance are recognized over time on a ratable basis over the term of the license. Revenue for maintenance, software post-contract support and maintenance, and SaaS is recognized over time on a ratable basis over the contract term. Revenue from education, training, and professional services is recognized over time as services are completed or ratably over the contractual period of generally one year or less. Deferred product revenue represents unrecognized revenue related to undelivered product commitments and other shipments that have not met revenue recognition criteria. Deferred service revenue represents billed amounts for service contracts, which include technical support, hardware and software maintenance, professional services, SaaS, and education and training, for which services have not been rendered.
Deferred Commissions	Deferred Commissions Sales commissions earned by the Company’s sales force are considered incremental and recoverable costs of obtaining a contract with a customer. These costs are recorded as prepaid expenses or other long-term assets and are deferred and then amortized over a period of benefit which is typically over the term of the customer contracts. Amortization expense is included in sales and marketing expenses in the accompanying Consolidated Statements of Operations.
Research and Development	Research and DevelopmentCosts to research, design, and develop the Company's products are expensed as incurred.
Software Development Costs	Software Development Costs Capitalization of software development costs for software to be sold, leased, or otherwise marketed begins when a product's technological feasibility has been established and ends when a product is available for general release to customers. Generally, the Company's products are released soon after technological feasibility has been established. As a result, costs incurred between achieving technological feasibility and product general availability have not been significant. The Company capitalizes costs associated with internal-use software systems during the application development stage. Such capitalized costs include external direct costs incurred in developing or obtaining the applications and payroll and payroll-related costs for employees, who are directly associated with the development of the applications.
Advertising	AdvertisingAdvertising costs are charged to sales and marketing expense as incurred.
Share-Based Compensation	Share-Based Compensation The Company measures and recognizes compensation cost for all share-based awards made to employees and directors, including employee stock options, restricted stock awards ("RSAs"), restricted stock units ("RSUs"), performance share awards ("PSAs") and employee stock purchases related to the Employee Stock Purchase Plan ("ESPP"). For service condition only awards, share-based compensation expense is based on the fair value of the underlying awards and amortized on a straight-line basis. For PSAs, share-based compensation expense is amortized on a straight-line basis for each separate vesting portion of the awards. The Company accounts for forfeitures as they occur. The Company utilizes the Black-Scholes-Merton (“BSM”) option-pricing model to estimate the fair value of its ESPP purchase rights. The BSM model requires various highly subjective assumptions that represent management's best estimates of volatility, risk-free interest rate, expected life, and dividend yield. The Company estimates expected volatility based on the implied volatility of market-traded options, on the Company's common stock, adjusted for other relevant factors including historical volatility of the Company’s common stock over the most recent period commensurate with the estimated expected life of the Company’s ESPP. The expected life of ESPP purchase rights approximates the offering period. The Company determines the grant date fair value of its RSUs, RSAs, and PSAs based on the closing market price of the Company’s common stock on the date of grant, adjusted by the present value of the 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.
Provision for Income Taxes	Provision for Income Taxes Deferred tax assets and liabilities are recognized for the expected tax consequences of temporary differences between the tax basis of assets and liabilities and their reported amounts. Valuation allowances are recorded to reduce deferred tax assets to the amount that will more likely than not be realized. The Company accounts for uncertainty in income taxes using a two-step approach to recognize and measure uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence
Concentrations of Risk	Concentrations of Risk Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, investments, derivatives, and accounts receivable. The Company invests only in high-quality credit instruments and maintains its cash, cash equivalents and available-for-sale investments in fixed income securities with several high-quality institutions. Deposits held with banks, including those held in foreign branches of global banks, may exceed the amount of insurance provided on such deposits. We mitigate the concentration of credit risk in our investment portfolio through diversification of the investments in various industries and asset classes, and limits to the amount of credit exposure to any single issuer and credit rating. The Company’s derivatives expose it to credit risk to the extent that counterparties may be unable to meet the terms of the agreement. The Company has a risk assessment and mitigation framework to evaluate the potential risk of loss with any one counterparty resulting from this type of credit risk. As part of this risk mitigation framework, the Company transacts with major financial institutions with high credit ratings and also enters into master netting agreements, which permit net settlement of the transactions with the same counterparty. The Company performs periodic evaluations of the relative credit standing of these financial institutions. Therefore, the Company does not expect material losses as a result of defaults by counterparties. Generally, credit risk with respect to accounts receivable is diversified due to the number of entities comprising the Company's customer base and their dispersion across different geographic locations throughout the world. The Company performs ongoing credit evaluations of its customers and generally does not require collateral on accounts receivable. During the years ended December 31, 2021, 2020, and 2019, no single customer accounted for 10% or more of net revenues.
Recently Adopted Accounting Standard 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, 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. 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 does not expect adoption and transition to alternative reference rates to have a material impact on its Consolidated Financial Statements. Accounting for Contract Assets and Contract Liabilities from Contracts with Customers: In October, 2021, the FASB issued ASU No. 2021-08 (Topic 805), Accounting for Contract Assets and Contract Liabilities from Contracts with Customers, which requires contract assets and contract liabilities acquired in a business combination to be recognized and measured by the acquirer on the acquisition date in accordance with ASC 606, Revenue from Contracts with Customers, as if it had originated the contracts. The standard is effective for the Company’s fiscal year beginning January 1, 2023, with early adoption permitted. The Company is currently evaluating the effect of this pronouncement on its Consolidated Financial Statements.
Earnings Per Share	Basic net income per share is computed using net income available to common stockholders and the weighted-average number of common shares outstanding for the period. Diluted net income per share is computed using net income available to common stockholders and the weighted-average number of common shares outstanding plus potentially dilutive common shares outstanding during the period. Dilutive potential common shares consist of common shares issuable upon exercise of stock options and purchase rights, and vesting of RSUs, RSAs, and PSAs. The Company includes the common shares underlying PSAs in the calculation of diluted net income per share only when they become contingently issuable. Anti-dilutive shares are excluded from the computation of diluted net income per share.

Description of Business, Basi_3

Description of Business, Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of Property and Equipment, Net	Property and equipment are recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method, over the estimated useful lives of the following assets: Estimated Useful Life (years) Computers, equipment, and software 1.5 to 10 Furniture and fixtures 5 to 7 Building and building improvements 7 to 40 Land improvements 10 to 40 Leasehold improvements Lease term, not to exceed 10 years Property and equipment, net, consisted of the following (in millions): As of December 31, 2021 2020 Computers and equipment $ 1,023.5 $ 1,057.5 Software 226.8 231.1 Leasehold improvements 197.6 223.8 Furniture and fixtures 46.8 49.6 Building and building improvements 269.3 256.0 Land and land improvements 243.5 243.5 Construction-in-process 11.2 17.7 Property and equipment, gross 2,018.7 2,079.2 Accumulated depreciation (1,315.7) (1,316.9) Property and equipment, net $ 703.0 $ 762.3

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
Business Combinations (Tables)	Dec. 31, 2021
Business Combination and Asset Acquisition [Abstract]
Schedule of Estimated Fair Values of Assets Acquired and Liabilities Assumed	The following table summarizes the fair values of the assets acquired and liabilities assumed at the acquisition dates (in millions): 2021 2020 Apstra WiteSand 128 Technology Netrounds Cash and cash equivalents $ 1.8 $ 1.5 $ 29.1 $ 1.0 Goodwill 84.0 10.2 298.8 24.7 Intangible assets 87.8 9.3 116.7 8.7 Other assets acquired 12.6 0.8 14.3 0.8 Liabilities assumed (6.8) — (10.7) (1.6) Total $ 179.4 $ 21.8 $ 448.2 $ 33.6
Schedule of 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 and the period over which each intangible asset will be amortized (in millions, except years): 2021 2020 Apstra WiteSand 128 Technology Netrounds Weighted Amount Weighted Amount Weighted Amount Weighted Amount Intangible assets: Existing technology 5 $ 80.5 5 $ 9.3 5 $ 88.0 4 $ 5.3 Customer relationships 1.5 7.3 — — 5 27.0 5 3.4 Backlog — — — — 1.5 1.7 — — Total intangible assets acquired $ 87.8 $ 9.3 $ 116.7 $ 8.7

Cash Equivalents and Investme_2

Cash Equivalents and Investments (Tables)	12 Months Ended
Cash Equivalents and Investments (Tables)	Dec. 31, 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 December 31, 2021 and December 31, 2020 (in millions): As of December 31, 2021 As of December 31, 2020 Amortized Gross Unrealized Gross Unrealized Estimated Fair Amortized Gross Unrealized Gross Unrealized Estimated Fair Fixed income securities: Asset-backed and mortgage-backed securities $ 139.1 $ — $ (0.5) $ 138.6 $ 76.5 $ 0.2 $ — $ 76.7 Certificates of deposit 5.0 — — 5.0 32.9 — — 32.9 Commercial paper 75.8 — — 75.8 89.3 — — 89.3 Corporate debt securities 443.3 0.7 (1.5) 442.5 632.0 5.5 (0.1) 637.4 Foreign government debt securities 12.8 — (0.1) 12.7 4.6 — — 4.6 Time deposits 35.2 — — 35.2 255.6 — — 255.6 U.S. government agency securities 26.8 — (0.1) 26.7 65.3 0.2 — 65.5 U.S. government securities 73.5 0.1 — 73.6 232.8 1.0 — 233.8 Total fixed income securities 811.5 0.8 (2.2) 810.1 1,389.0 6.9 (0.1) 1,395.8 Privately-held debt and redeemable preferred stock securities 9.6 37.4 — $ 47.0 18.3 37.4 — 55.7 Total available-for-sale debt securities $ 821.1 $ 38.2 $ (2.2) $ 857.1 $ 1,407.3 $ 44.3 $ (0.1) $ 1,451.5 Reported as: Cash equivalents $ 47.2 $ — $ — $ 47.2 $ 333.7 $ — $ — $ 333.7 Short-term investments 306.8 0.7 (0.1) 307.4 404.3 1.2 — 405.5 Long-term investments 457.5 0.1 (2.1) 455.5 651.0 5.7 (0.1) 656.6 Other long-term assets 9.6 37.4 — 47.0 18.3 37.4 — 55.7 Total $ 821.1 $ 38.2 $ (2.2) $ 857.1 $ 1,407.3 $ 44.3 $ (0.1) $ 1,451.5
Schedule of Maturities of Fixed Income Securities	The following table presents the contractual maturities of the Company's total fixed income securities as of December 31, 2021 (in millions): Amortized Estimated Fair Due in less than one year $ 354.0 $ 354.6 Due between one and five years 457.5 455.5 Total $ 811.5 $ 810.1
Schedule of Investments in Equity Securities	The following table presents the Company's investments in equity securities as of December 31, 2021 and 2020 (in millions): As of December 31, 2021 2020 Equity investments with readily determinable fair value Money market funds $ 382.0 $ 536.6 Mutual funds 33.4 29.3 Publicly-traded equity securities 8.1 6.6 Equity investments without readily determinable fair value 150.1 146.2 Total equity securities $ 573.6 $ 718.7 Reported as: Cash equivalents $ 371.5 $ 519.8 Short-term investments 8.1 6.6 Prepaid expenses and other current assets 15.1 9.9 Other long-term assets 178.9 182.4 Total $ 573.6 $ 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 Consolidated Balance Sheets as of December 31, 2021 and December 31, 2020 (in millions): As of December 31, 2021 2020 Cash and cash equivalents $ 922.5 $ 1,361.9 Restricted cash included in Prepaid expenses and other current assets 17.2 19.2 Restricted cash included in Other long-term assets 3.0 1.9 Total cash, cash equivalents, and restricted cash $ 942.7 $ 1,383.0

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of 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 Consolidated Balance Sheets (in millions): Fair Value Measurements at December 31, 2021 Fair Value Measurements at December 31, 2020 Quoted Prices in Significant Other Significant Other Total Quoted Prices in Significant Other Significant Other Total Assets: Available-for-sale debt securities: Asset-backed and mortgage-backed securities $ — $ 138.6 $ — $ 138.6 $ — $ 76.7 $ — $ 76.7 Certificates of deposit — 5.0 — 5.0 — 32.9 — 32.9 Commercial paper — 75.8 — 75.8 — 89.3 — 89.3 Corporate debt securities — 442.5 — 442.5 — 637.4 — 637.4 Foreign government debt securities — 12.7 — 12.7 — 4.6 — 4.6 Time deposits — 35.2 — 35.2 — 255.6 — 255.6 U.S. government agency securities — 26.7 — 26.7 — 65.5 — 65.5 U.S. government securities 42.3 31.3 — 73.6 140.0 93.8 — 233.8 Privately-held debt and redeemable preferred stock securities — — 47.0 47.0 — — 55.7 55.7 Total available-for-sale debt securities 42.3 767.8 47.0 857.1 140.0 1,255.8 55.7 1,451.5 Equity securities: Money market funds 382.0 — — 382.0 536.6 — — 536.6 Mutual funds 33.4 — — 33.4 29.3 — — 29.3 Publicly-traded equity securities 8.1 — — 8.1 6.6 — — 6.6 Total equity securities 423.5 — — 423.5 572.5 — — 572.5 Derivative assets: Foreign exchange contracts — 9.2 — 9.2 — 38.0 — 38.0 Interest rate contracts — 47.1 — 47.1 — 51.0 — 51.0 Total derivative assets — 56.3 — 56.3 — 89.0 — 89.0 Total assets measured at fair value on a recurring basis $ 465.8 $ 824.1 $ 47.0 $ 1,336.9 $ 712.5 $ 1,344.8 $ 55.7 $ 2,113.0 Liabilities: Derivative liabilities: Foreign exchange contracts $ — $ (24.0) $ — $ (24.0) $ — $ (0.5) $ — $ (0.5) Interest rate contracts — (2.5) — (2.5) — — — — Total derivative liabilities — (26.5) — (26.5) — (0.5) — (0.5) Total liabilities measured at fair value on a recurring basis $ — $ (26.5) $ — $ (26.5) $ — $ (0.5) $ — $ (0.5) Total assets, reported as: Cash equivalents $ 371.6 $ 47.2 $ — $ 418.8 $ 519.8 $ 333.7 $ — $ 853.5 Short-term investments 41.5 274.0 — 315.5 101.0 311.1 — 412.1 Long-term investments 8.8 446.7 — 455.5 45.6 611.0 — 656.6 Prepaid expenses and other current assets 15.1 8.8 — 23.9 9.9 28.0 — 37.9 Other long-term assets 28.8 47.4 47.0 123.2 36.2 61.0 55.7 152.9 Total assets measured at fair value on a recurring basis $ 465.8 $ 824.1 $ 47.0 $ 1,336.9 $ 712.5 $ 1,344.8 $ 55.7 $ 2,113.0 Fair Value Measurements at December 31, 2021 Fair Value Measurements at December 31, 2020 Quoted Prices in Significant Other Significant Other Total Quoted Prices in Significant Other Significant Other Total Total liabilities, reported as: Other accrued liabilities $ — $ (14.9) $ — $ (14.9) $ — $ (0.3) $ — $ (0.3) Other long-term liabilities — (11.6) — (11.6) — (0.2) — (0.2) Total liabilities measured at fair value on a recurring basis $ — $ (26.5) $ — $ (26.5) $ — $ (0.5) $ — $ (0.5)

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
Derivative Instruments (Tables)	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The notional amount of the Company's derivative instruments is summarized as follows (in millions): As of December 31, 2021 2020 Designated derivatives: Cash flow hedges: Foreign currency contracts $ 873.9 $ 722.1 Interest rate lock contracts 650.0 650.0 Fair value hedges: Interest rate swap contracts 600.0 300.0 Total designated derivatives $ 2,123.9 $ 1,672.1 Non-designated derivatives 144.6 174.1 Total $ 2,268.5 $ 1,846.2
Schedule of Derivative Liabilities at Fair Value	The fair value of derivative instruments on the Consolidated Balance Sheets was as follows: As of December 31, Balance Sheet Location 2021 2020 Derivative assets: Derivatives designated as hedging instruments: Foreign currency contracts as cash flow hedges Other current assets $ 8.7 $ 27.8 Foreign currency contracts as cash flow hedges Other long-term assets 0.4 10.0 Interest rate lock contracts Other long-term assets 45.0 30.7 Interest rate swap contracts Other long-term assets 2.1 20.3 Total derivatives designated as hedging instruments $ 56.2 $ 88.8 Derivatives not designated as hedging instruments Other current assets 0.1 0.2 Total derivative assets $ 56.3 $ 89.0 Derivative liabilities: Derivatives designated as hedging instruments: Foreign currency contracts Other accrued liabilities $ 14.8 $ 0.2 Foreign currency contracts Other long-term liabilities 9.1 0.2 Interest rate swap contracts Other long-term liabilities 2.5 — Total derivatives designated as hedging instruments $ 26.4 $ 0.4 Derivatives not designated as hedging instruments Other accrued liabilities 0.1 0.1 Total derivative liabilities $ 26.5 $ 0.5
Schedule of Derivative Assets at Fair Value	The fair value of derivative instruments on the Consolidated Balance Sheets was as follows: As of December 31, Balance Sheet Location 2021 2020 Derivative assets: Derivatives designated as hedging instruments: Foreign currency contracts as cash flow hedges Other current assets $ 8.7 $ 27.8 Foreign currency contracts as cash flow hedges Other long-term assets 0.4 10.0 Interest rate lock contracts Other long-term assets 45.0 30.7 Interest rate swap contracts Other long-term assets 2.1 20.3 Total derivatives designated as hedging instruments $ 56.2 $ 88.8 Derivatives not designated as hedging instruments Other current assets 0.1 0.2 Total derivative assets $ 56.3 $ 89.0 Derivative liabilities: Derivatives designated as hedging instruments: Foreign currency contracts Other accrued liabilities $ 14.8 $ 0.2 Foreign currency contracts Other long-term liabilities 9.1 0.2 Interest rate swap contracts Other long-term liabilities 2.5 — Total derivatives designated as hedging instruments $ 26.4 $ 0.4 Derivatives not designated as hedging instruments Other accrued liabilities 0.1 0.1 Total derivative liabilities $ 26.5 $ 0.5

Goodwill and Purchased Intang_2

Goodwill and Purchased Intangible Assets (Tables)	12 Months Ended
Goodwill and Purchased Intangible Assets (Tables)	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The Company's goodwill activity was as follows (in millions): Total December 31, 2019 $ 3,337.1 Additions due to business combinations 332.5 December 31, 2020 3,669.6 Additions due to business combinations 92.5 December 31, 2021 $ 3,762.1
Schedule of Acquired Indefinite-Lived Intangible Assets by Major Class	The Company’s purchased intangible assets, net, were as follows (in millions): As of December 31, 2021 As of December 31, 2020 Gross Accumulated Accumulated Impairments and Net Gross Accumulated Accumulated Impairments and Net Finite-lived intangible assets: Technologies and patents $ 913.1 $ (660.7) $ (55.1) $ 197.3 $ 823.5 $ (598.2) $ (55.1) $ 170.2 Customer contracts, support agreements, and related relationships 136.3 (98.6) (2.8) 34.9 129.2 (84.4) (2.8) 42.0 Trade names and other 9.6 (6.5) — 3.1 9.6 (4.1) — 5.5 Total 1,059.0 (765.8) (57.9) 235.3 962.3 (686.7) (57.9) 217.7 Indefinite-lived intangible assets: IPR&D 49.0 — — 49.0 49.0 — — 49.0 Total purchased intangible assets $ 1,108.0 $ (765.8) $ (57.9) $ 284.3 $ 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 December 31, 2021 As of December 31, 2020 Gross Accumulated Accumulated Impairments and Net Gross Accumulated Accumulated Impairments and Net Finite-lived intangible assets: Technologies and patents $ 913.1 $ (660.7) $ (55.1) $ 197.3 $ 823.5 $ (598.2) $ (55.1) $ 170.2 Customer contracts, support agreements, and related relationships 136.3 (98.6) (2.8) 34.9 129.2 (84.4) (2.8) 42.0 Trade names and other 9.6 (6.5) — 3.1 9.6 (4.1) — 5.5 Total 1,059.0 (765.8) (57.9) 235.3 962.3 (686.7) (57.9) 217.7 Indefinite-lived intangible assets: IPR&D 49.0 — — 49.0 49.0 — — 49.0 Total purchased intangible assets $ 1,108.0 $ (765.8) $ (57.9) $ 284.3 $ 1,011.3 $ (686.7) $ (57.9) $ 266.7
Schedule of Estimated Future Amortization Expense of Purchased Intangible Assets with Finite Lives	As of December 31, 2021, the estimated future amortization expense of purchased intangible assets with finite lives was as follows (in millions): Years Ending December 31, Amount 2022 $ 74.9 2023 68.7 2024 49.2 2025 39.6 2026 2.9 Total $ 235.3

Other Financial Information (Ta

Other Financial Information (Tables)	12 Months Ended
Other Financial Information (Tables)	Dec. 31, 2021
Other Financial Information [Abstract]
Schedule of Inventories	Total inventory consisted of the following (in millions): As of December 31, 2021 2020 Production and service materials $ 208.6 $ 158.1 Finished goods 75.6 63.8 Total inventory $ 284.2 $ 221.9 Reported as: Inventory $ 272.6 $ 210.2 Other long-term assets 11.6 11.7 Total inventory $ 284.2 $ 221.9
Schedule of Property and Equipment, Net	Property and equipment are recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method, over the estimated useful lives of the following assets: Estimated Useful Life (years) Computers, equipment, and software 1.5 to 10 Furniture and fixtures 5 to 7 Building and building improvements 7 to 40 Land improvements 10 to 40 Leasehold improvements Lease term, not to exceed 10 years Property and equipment, net, consisted of the following (in millions): As of December 31, 2021 2020 Computers and equipment $ 1,023.5 $ 1,057.5 Software 226.8 231.1 Leasehold improvements 197.6 223.8 Furniture and fixtures 46.8 49.6 Building and building improvements 269.3 256.0 Land and land improvements 243.5 243.5 Construction-in-process 11.2 17.7 Property and equipment, gross 2,018.7 2,079.2 Accumulated depreciation (1,315.7) (1,316.9) Property and equipment, net $ 703.0 $ 762.3
Schedule of Warranties	Changes in the Company’s warranty reserve were as follows (in millions): As of December 31, 2021 2020 Beginning balance $ 30.2 $ 31.4 Provisions made during the period, net 39.5 37.1 Actual costs incurred during the period (36.7) (38.3) Ending balance $ 33.0 $ 30.2
Schedule of Performance Obligation	The following table summarizes the breakdown of RPO as of December 31, 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 $ 135.8 $ 117.1 $ 15.6 $ 3.1 Service 1,296.0 828.7 371.1 96.2 Total $ 1,431.8 $ 945.8 $ 386.7 $ 99.3
Schedule of Other Expense, Net	Other expense, net consisted of the following (in millions): Years Ended December 31, 2021 2020 2019 Interest income $ 14.9 $ 36.3 $ 79.1 Interest expense (50.8) (77.0) (88.7) Gain (loss) on investments, net 17.6 13.3 (3.8) Other 1.5 (5.5) 0.9 Other expense, net $ (16.8) $ (32.9) $ (12.5)

Restructuring Charges (Tables)

Restructuring Charges (Tables)	12 Months Ended
Restructuring Charges (Tables)	Dec. 31, 2021
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Charges	The following table presents restructuring charges included in the Consolidated Statements of Operations (in millions): Years Ended December 31, 2021 2020 2019 Severance $ 13.6 $ 62.8 $ 21.5 Facility consolidations 8.1 5.2 2.1 Contract terminations and other 21.2 — 11.7 Total $ 42.9 $ 68.0 $ 35.3 Reported as: Restructuring charges $ 42.9 $ 68.0 $ 35.3 Total $ 42.9 $ 68.0 $ 35.3
Schedule of Restructuring Liabilities	The following table provides a summary of changes in the restructuring liabilities associated with the 2021 Restructuring Plan and 2020 Restructuring Plan (in millions): December 31, Charges/ Cash Other December 31, Severance $ 50.7 $ 13.6 $ (63.9) $ 1.0 $ 1.4 Facility consolidations — 8.1 — (8.1) — Contract terminations and other — 21.2 (4.5) (5.8) 10.9 Total $ 50.7 $ 42.9 $ (68.4) $ (12.9) $ 12.3

Debt and Financing (Tables)

Debt and Financing (Tables)	12 Months Ended
Debt and Financing (Tables)	Dec. 31, 2021
Debt Instruments [Abstract]
Schedule of Long-term Debt	The following table summarizes the Company's total debt (in millions, except percentages): As of December 31, Maturity Date Effective Interest 2021 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 (12.9) (16.8) Hedge accounting fair value adjustments () (0.3) 20.3 Total $ 1,686.8 $ 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.
Schedule of Maturities of Long-term Debt	As of December 31, 2021, the Company's aggregate debt maturities based on outstanding principal were as follows (in millions): Years Ending December 31, Amount 2022 $ — 2023 — 2024 — 2025 400.0 2026 — Thereafter 1,300.0 Total $ 1,700.0

Equity (Tables)

Equity (Tables)	12 Months Ended
Equity (Tables)	Dec. 31, 2021
Equity [Abstract]
Schedule of Dividends Paid and Stock Repurchases and Retirements Under Stock Repurchase Program	The following table summarizes dividends paid, stock repurchases and retirements under the Company's stock repurchase programs, and stock repurchases for tax withholdings (in millions, except per share amounts): Dividends Stock Repurchases Total Year Per Share Amount Shares Average price () Amount Tax Withholding Amount 2021 $ 0.80 $ 259.1 15.7 $ 27.56 $ 433.3 $ 10.2 $ 702.6 2020 $ 0.80 $ 264.1 17.9 $ 23.47 $ 375.0 $ 6.2 $ 645.3 2019 $ 0.76 $ 260.1 20.1 $ 25.36 $ 550.0 $ 5.0 $ 815.1 ________________________________ () $23.47 average price per share for 2020 includes $375.0 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 (loss), net of related taxes, for the years ended December 31, 2021, 2020, and 2019 were as follows (in millions): Unrealized Gains/Losses on Available-for- Sale Debt Securities (1) Unrealized Gains/Losses on Cash Flow Hedges (2) Foreign Total Balance as of December 31, 2018 $ 25.5 $ (0.9) $ (42.8) $ (18.2) Other comprehensive income (loss) before reclassifications 4.6 (8.9) (1.1) (5.4) Amount reclassified from accumulated other comprehensive income (loss) (0.4) 5.5 — 5.1 Other comprehensive income (loss), net 4.2 (3.4) (1.1) (0.3) Balance as of December 31, 2019 $ 29.7 $ (4.3) $ (43.9) $ (18.5) Other comprehensive income before reclassifications 5.7 54.4 7.7 67.8 Amount reclassified from accumulated other comprehensive income (loss) (1.3) 7.6 — 6.3 Other comprehensive income, net 4.4 62.0 7.7 74.1 Balance as of December 31, 2020 $ 34.1 $ 57.7 $ (36.2) $ 55.6 Other comprehensive loss before reclassifications (5.0) (13.5) (12.8) (31.3) Amount reclassified from accumulated other comprehensive income (loss) (1.2) (25.2) — (26.4) Other comprehensive loss, net (6.2) (38.7) (12.8) (57.7) Balance as of December 31, 2021 $ 27.9 $ 19.0 $ (49.0) $ (2.1) ________________________________ (1) The reclassifications out of accumulated other comprehensive income (loss) during the years ended December 31, 2021, 2020 , and 2019 for realized gains on available-for-sale debt securities were not material, and were included in other expense, net, in the Consolidated Statements of Operations. (2) The reclassifications out of accumulated other comprehensive income (loss) for realized gains and losses on cash flow hedges was $28.9 million for the year ended December 31, 2021 and not material for the years ended 2020 and 2019. The reclassified amounts were included within cost of revenues, research and development, sales and marketing, and general and administrative in the Consolidated Statements of Operations.

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
Employee Benefit Plans (Tables)	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Nonvested Share Activity	The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the year ended December 31, 2021 (in millions, except per share amounts and years): Outstanding RSUs, RSAs, and PSAs Number of Shares Weighted Average Weighted Average Aggregate Balance at December 31, 2020 19.9 $ 23.05 Granted (1)(2) 10.2 26.19 Awards assumed upon the acquisitions of Apstra and WiteSand (2) 2.5 26.28 Vested (3) (7.8) 23.66 Canceled (2.6) 23.91 Balance at December 31, 2021 22.2 $ 24.55 1.3 $ 791.3 As of December 31, 2021 Vested and expected-to-vest RSUs, RSAs, and PSAs 19.7 $ 24.96 1.3 $ 703.7 ________________________________ (1) Includes 8.2 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. (2) The weighted-average grant-date fair value of RSUs, RSAs, and PSAs granted and assumed or substituted during 2021, 2020, and 2019 was $26.21, $21.59, and $25.26, respectively. 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. During 2021, the Company declared a quarterly cash dividend of $0.20 per share of common stock on January 28, 2021, April 27, 2021, July 27, 2021 and October 26, 2021. (3) Total fair value of RSUs, RSAs, and PSAs vested during 2021, 2020, and 2019 was $184.2 million, $174.7 million, and $170.0 million, respectively.
Shares Available for Grant	The following table presents the stock activity and the total number of shares available for grant under the 2015 Plan (in millions): Number of Shares Balance as of December 31, 2020 12.1 Additional shares authorized — RSUs and PSAs granted () (10.5) RSUs and PSAs canceled () 3.5 Balance as of December 31, 2021 5.1 ________________________________ (*) In May 2019, the 2015 Plan was amended, and the amendment removed the fungible share adjustment used to determine shares available for issuance. Under the original terms of the 2015 Plan, RSUs and PSAs with a per share or unit purchase price lower than 100% of the fair market value of the Company's common stock on the day of the grant were counted against shares authorized under the plan as two and one-tenth shares of common stock ("the prior fungible rate") for each share subject to such award. Pursuant to the amendment, beginning on May 14, 2019, each share award granted under the 2015 Plan reduces the share reserve by one share and all share awards granted on May 14, 2019 and thereafter that are later forfeited, canceled or terminated are returned to the share reserve in the same manner. During 2021, among the total 3.5 million of canceled shares, 2.2 million shares represent the shares returned to the share reserve at the prior fungible rate. The number of shares subject to PSAs granted represents the maximum number of shares that may be issued pursuant to the award over its full term.
Schedule Of Share-based Payment Award, Stock Options and Employee Stock Purchase Plan, Valuation Assumptions	The weighted-average assumptions used and the resulting estimates of fair value for ESPP purchase rights and market-based RSUs were as follows: Years Ended December 31, 2021 2020 2019 ESPP Purchase Rights: Volatility 32% 31% 27% Risk-free interest rate 0.1% 0.8% 2.1% Expected life (years) 1.3 1.3 1.2 Dividend yield 3.0% 3.3% 2.9% Weighted-average fair value per share $6.96 $6.34 $6.65 Market-based RSUs: Volatility 30% 25% 25% Risk-free interest rate 0.2% 1.3% 2.4% Dividend yield 3.4% 3.3% 2.8% Weighted-average fair value per share $30.70 $26.32 $27.32
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	Share-based compensation expense associated with stock options, RSUs, RSAs, PSAs, and ESPP purchase rights was recorded in the following cost and expense categories in the Company's Consolidated Statements of Operations (in millions): Years Ended December 31, 2021 2020 2019 Cost of revenues - Product $ 5.3 $ 5.4 $ 5.7 Cost of revenues - Service 18.2 15.8 17.3 Research and development 93.1 78.8 94.0 Sales and marketing 65.9 58.2 56.0 General and administrative 40.1 31.4 29.2 Total $ 222.6 $ 189.6 $ 202.2
Schedule of Disclosure of Share-based Compensation Arrangements by Share-based Payment Award	The following table summarizes share-based compensation expense by award type (in millions): Years Ended December 31, 2021 2020 2019 Stock options $ 9.3 $ 7.3 $ 7.7 RSUs, RSAs, and PSAs 196.2 162.6 176.5 ESPP Purchase Rights 17.1 19.7 18.0 Total $ 222.6 $ 189.6 $ 202.2

Segments (Tables)

Segments (Tables)	12 Months Ended
Segments (Tables)	Dec. 31, 2021
Segment Reporting [Abstract]
Schedule of Financial Information by Segment	The following table presents net revenues by customer solution (in millions): Years Ended December 31, 2021 2020 2019 Customer Solutions: Automated WAN Solutions $ 1,665.0 $ 1,622.2 $ 1,604.4 Cloud-Ready Data Center 727.1 677.1 726.5 AI-Driven Enterprise 830.4 656.2 613.8 Hardware Maintenance and Professional Services 1,512.9 1,489.6 1,500.7 Total $ 4,735.4 $ 4,445.1 $ 4,445.4 The following table presents net revenues by customer vertical (in millions): Years Ended December 31, 2021 2020 2019 Cloud $ 1,228.0 $ 1,081.2 $ 1,059.8 Service Provider 1,839.1 1,761.7 1,827.8 Enterprise 1,668.3 1,602.2 1,557.8 Total $ 4,735.4 $ 4,445.1 $ 4,445.4
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): Years Ended December 31, 2021 2020 2019 Americas: United States $ 2,426.9 $ 2,233.9 $ 2,299.8 Other 222.2 211.2 218.2 Total Americas 2,649.1 2,445.1 2,518.0 Europe, Middle East, and Africa 1,314.5 1,233.8 1,215.3 Asia Pacific 771.8 766.2 712.1 Total $ 4,735.4 $ 4,445.1 $ 4,445.4
Schedule of Property and Equipment by Geographic Region	The following table presents geographic information for property and equipment, net (in millions). As of December 31, 2021 2020 United States $ 623.4 $ 667.4 International 79.6 94.9 Property and equipment, net $ 703.0 $ 762.3

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Components of Pretax Income	The components of pretax income are summarized as follows (in millions): Years Ended December 31, 2021 2020 2019 Domestic $ 264.6 $ 204.2 $ 296.2 Foreign 45.5 61.0 118.2 Total pretax income $ 310.1 $ 265.2 $ 414.4
Schedule of Components of Provision (Benefit) for Income Taxes	The provision (benefit) for income taxes is summarized as follows (in millions): Years Ended December 31, 2021 2020 2019 Current provision (benefit): Federal $ 63.4 $ 73.4 $ 6.2 States 15.9 20.3 14.4 Foreign 48.2 (21.6) 48.5 Total current provision (benefit) 127.5 72.1 69.1 Deferred (benefit) provision: Federal (54.3) (58.7) 0.8 States (4.1) (6.6) 2.8 Foreign (11.7) 0.6 (3.3) Total deferred (benefit) provision (70.1) (64.7) 0.3 Total provision (benefit) for income taxes $ 57.4 $ 7.4 $ 69.4
Schedule of Effective Income Tax Rate Reconciliation	The provision (benefit) for income taxes differs from the amount computed by applying the federal statutory tax rate of 21% to pretax income for each of the years presented as follows (in millions): Years Ended December 31, 2021 2020 2019 Expected provision at statutory rate $ 65.1 $ 55.7 $ 87.0 State taxes, net of federal benefit 6.5 8.7 9.4 Foreign income at different tax rates (0.2) (5.9) 1.8 R&D tax credits (16.6) (16.4) (18.8) Share-based compensation (2.2) 9.0 3.8 Non-deductible compensation 4.2 3.5 3.3 Temporary differences not currently benefited — (0.9) 12.9 Recognition of previously unrecognized tax benefits — (63.7) (25.4) Cost sharing adjustment- Altera — 20.1 — Lapses in federal statutes of limitations — — (7.5) Other 0.6 (2.7) 2.9 Total provision (benefit) for income taxes $ 57.4 $ 7.4 $ 69.4
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company's long-term deferred tax assets and deferred tax liabilities are as follows (in millions): As of December 31, 2021 2020 Deferred tax assets: Net operating loss carry-forwards $ 72.5 $ 48.2 Research and other credit carry-forwards 272.2 252.8 Deferred revenue 47.7 43.4 Share-based compensation 17.9 15.0 Capitalized R&D expenditure 102.0 60.5 Reserves and accruals not currently deductible 61.0 43.5 Operating lease liabilities 45.4 51.3 Other 9.9 10.6 Total deferred tax assets 628.6 525.3 Valuation allowance (300.9) (261.5) Deferred tax assets, net of valuation allowance 327.7 263.8 Deferred tax liabilities: Property and equipment basis differences (1.3) (20.1) Purchased intangible assets (56.5) (45.6) Unremitted foreign earnings (25.5) (25.5) Net unrealized gain (21.0) (21.1) Operating lease assets (39.9) (44.9) Total deferred tax liabilities (144.2) (157.2) Net deferred tax assets $ 183.5 $ 106.6
Schedule of Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of the Company's total gross unrecognized tax benefits was as follows (in millions): Years Ended December 31, 2021 2020 2019 Balance at beginning of year $ 116.0 $ 151.3 $ 178.1 Tax positions related to current year: Additions 7.7 5.3 5.9 Tax positions related to prior years: Additions 3.3 18.1 0.8 Reductions (3.6) (52.0) (3.3) Settlements (9.4) (1.8) (22.5) Lapses in statutes of limitations (0.6) (4.9) (7.7) Balance at end of year $ 113.4 $ 116.0 $ 151.3

Net Income per Share (Tables)

Net Income per Share (Tables)	12 Months Ended
Net Income per Share (Tables)	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Calculation of Basic and Diluted Net Income Per Share	The Company computed basic and diluted net income per share as follows (in millions, except per share amounts): Years Ended December 31, 2021 2020 2019 Numerator: Net income $ 252.7 $ 257.8 $ 345.0 Denominator: Weighted-average shares used to compute basic net income per share 324.4 330.4 343.2 Dilutive effect of employee stock awards 7.2 4.8 5.0 Weighted-average shares used to compute diluted net income per share 331.6 335.2 348.2 Net income per share: Basic $ 0.78 $ 0.78 $ 1.01 Diluted $ 0.76 $ 0.77 $ 0.99 Anti-dilutive shares 0.5 5.3 4.7

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Unconditional Purchase Obligations	The following table summarizes the Company’s unconditional purchase obligations as of December 31, 2021 (in millions): Years Ending December 31, Unconditional Purchase Obligations 2022 $ 61.0 2023 43.9 2024 16.5 2025 7.3 2026 0.6 Total $ 129.3
Schedule of Lease Costs	The components of lease costs and other information related to leases were as follows (in millions, except years and percentages): Years Ended December 31, 2021 2020 Operating lease cost $ 57.4 $ 50.8 Variable lease cost 11.5 13.4 Total lease cost $ 68.9 $ 64.2 Operating cash outflows from operating leases $ 57.8 $ 54.2 ROU assets obtained in exchange for new operating lease liabilities $ 29.7 $ 54.7 As of December 31, 2021 2020 Weighted average remaining lease term (years) 4.6 4.9 Weighted average discount rate 3.3 % 3.7 %
Schedule of Future Operating Lease Payments	As of December 31, 2021, future operating lease payments for each of the next five years and thereafter are as follows (in millions): Years Ending December 31, Amount 2022 $ 48.7 2023 47.6 2024 43.1 2025 34.6 2026 14.3 Thereafter 15.3 Total lease payments 203.6 Less: interest (14.2) Total $ 189.4 Balance Sheet Information Other accrued liabilities $ 47.2 Long-term operating lease liabilities 142.2 Total $ 189.4
Schedule of Purchase Commitments	The following table summarizes the Company’s purchase commitments as of December 31, 2021 (in millions): Years Ending December 31, Purchase Commitments 2022 $ 2,094.3 2023 523.0 2024 14.4 2025 0.5 Total $ 2,632.2

Description of Business, Basi_4

Description of Business, Basis of Presentation and Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Warranty period for hardware products	1 year
Warranty period for software	90 days
Advertising expense	$ 26.6	$ 21.7	$ 14.6
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible assets, estimated useful life	4 years
Revenue from contract with customers, terms of payment	30 days
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible assets, estimated useful life	5 years
Revenue from contract with customers, terms of payment	90 days
Interest rate swap contracts \| Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Expiration period	9 years

Description of Business, Basi_5

Description of Business, Basis of Presentation and Significant Accounting Policies - Property, Plant and Equipment, Useful Lives (Details)	12 Months Ended
	Dec. 31, 2021
Computers, equipment, and software \| Minimum
Property and Equipment [Line Items]
Estimated Useful Life (years)	1 year 6 months
Computers, equipment, and software \| Maximum
Property and Equipment [Line Items]
Estimated Useful Life (years)	10 years
Furniture and fixtures \| Minimum
Property and Equipment [Line Items]
Estimated Useful Life (years)	5 years
Furniture and fixtures \| Maximum
Property and Equipment [Line Items]
Estimated Useful Life (years)	7 years
Building and building improvements \| Minimum
Property and Equipment [Line Items]
Estimated Useful Life (years)	7 years
Building and building improvements \| Maximum
Property and Equipment [Line Items]
Estimated Useful Life (years)	40 years
Land improvements \| Minimum
Property and Equipment [Line Items]
Estimated Useful Life (years)	10 years
Land improvements \| Maximum
Property and Equipment [Line Items]
Estimated Useful Life (years)	40 years
Leasehold improvements
Property and Equipment [Line Items]
Estimated Useful Life (years)	10 years

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Millions	Jan. 27, 2021	Nov. 30, 2020	Oct. 26, 2020	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Acquisition related costs					$ 8.9	$ 24.6
Apstra
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
WiteSand
Business Acquisition [Line Items]
Percentage of voting interest acquired				100.00%	100.00%
Consideration transferred, cash				$ 21.8
128 Technology
Business Acquisition [Line Items]
Percentage of voting interest acquired		100.00%
Consideration transferred		$ 448.2
Consideration transferred, cash		446.8
Consideration transferred, share-based awards		1.4
Share-based compensation assumed, fair value		$ 29.3
Netrounds
Business Acquisition [Line Items]
Percentage of voting interest acquired			100.00%
Consideration transferred, cash			$ 33.6

Business Combinations - Estimat

Business Combinations - Estimated Fair Value of Assets Acquired (Details) - USD ($) $ in Millions	Dec. 31, 2021	Jan. 27, 2021	Dec. 31, 2020	Nov. 30, 2020	Oct. 26, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill	$ 3,762.1		$ 3,669.6			$ 3,337.1
Apstra
Business Acquisition [Line Items]
Cash and cash equivalents		$ 1.8
Goodwill		84
Intangible assets		87.8
Other assets acquired		12.6
Liabilities assumed		(6.8)
Total		$ 179.4
WiteSand
Business Acquisition [Line Items]
Cash and cash equivalents	1.5
Goodwill	10.2
Intangible assets	9.3
Other assets acquired	0.8
Liabilities assumed	0
Total	$ 21.8
128 Technology
Business Acquisition [Line Items]
Cash and cash equivalents				$ 29.1
Goodwill				298.8
Intangible assets				116.7
Other assets acquired				14.3
Liabilities assumed				(10.7)
Total				$ 448.2
Netrounds
Business Acquisition [Line Items]
Cash and cash equivalents					$ 1
Goodwill					24.7
Intangible assets					8.7
Other assets acquired					0.8
Liabilities assumed					(1.6)
Total					$ 33.6

Business Combinations - Fair Va

Business Combinations - Fair Value of Identifiable Intangible Assets Acquired (Details) - USD ($) $ in Millions	Jan. 27, 2021	Nov. 30, 2020	Oct. 26, 2020	Dec. 31, 2021
Apstra
Business Acquisition [Line Items]
Intangible assets	$ 87.8
Apstra \| Existing technology
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)	5 years
Intangible assets	$ 80.5
Apstra \| Customer relationships
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)	1 year 6 months
Intangible assets	$ 7.3
WiteSand
Business Acquisition [Line Items]
Intangible assets				$ 9.3
WiteSand \| Existing technology
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)				5 years
Intangible assets				$ 9.3
128 Technology
Business Acquisition [Line Items]
Intangible assets		$ 116.7
128 Technology \| Existing technology
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)		5 years
Intangible assets		$ 88
128 Technology \| Customer relationships
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)		5 years
Intangible assets		$ 27
128 Technology \| Backlog
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)		1 year 6 months
Intangible assets		$ 1.7
Netrounds
Business Acquisition [Line Items]
Intangible assets			$ 8.7
Netrounds \| Existing technology
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)			4 years
Intangible assets			$ 5.3
Netrounds \| Customer relationships
Business Acquisition [Line Items]
Weighted Average Estimated Useful Life (In Years)			5 years
Intangible assets			$ 3.4

Cash Equivalents and Investme_3

Cash Equivalents and Investments - Available-For-Sale (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Available-for-sale debt securities:
Amortized Cost	$ 821.1	$ 1,407.3
Gross Unrealized Gains	38.2	44.3
Gross Unrealized Losses	(2.2)	(0.1)
Estimated Fair Value	857.1	1,451.5
Cash equivalents
Available-for-sale debt securities:
Amortized Cost	47.2	333.7
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	47.2	333.7
Short-term investments
Available-for-sale debt securities:
Amortized Cost	306.8	404.3
Gross Unrealized Gains	0.7	1.2
Gross Unrealized Losses	(0.1)	0
Estimated Fair Value	307.4	405.5
Long-term investments
Available-for-sale debt securities:
Amortized Cost	457.5	651
Gross Unrealized Gains	0.1	5.7
Gross Unrealized Losses	(2.1)	(0.1)
Estimated Fair Value	455.5	656.6
Other long-term assets
Available-for-sale debt securities:
Amortized Cost	9.6	18.3
Gross Unrealized Gains	37.4	37.4
Gross Unrealized Losses	0	0
Estimated Fair Value	47	55.7
Asset-backed and mortgage-backed securities
Available-for-sale debt securities:
Amortized Cost	139.1	76.5
Gross Unrealized Gains	0	0.2
Gross Unrealized Losses	(0.5)	0
Estimated Fair Value	138.6	76.7
Certificates of deposit
Available-for-sale debt securities:
Amortized Cost	5	32.9
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	5	32.9
Commercial paper
Available-for-sale debt securities:
Amortized Cost	75.8	89.3
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	75.8	89.3
Corporate debt securities
Available-for-sale debt securities:
Amortized Cost	443.3	632
Gross Unrealized Gains	0.7	5.5
Gross Unrealized Losses	(1.5)	(0.1)
Estimated Fair Value	442.5	637.4
Foreign government debt securities
Available-for-sale debt securities:
Amortized Cost	12.8	4.6
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(0.1)	0
Estimated Fair Value	12.7	4.6
Time deposits
Available-for-sale debt securities:
Amortized Cost	35.2	255.6
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	35.2	255.6
U.S. government agency securities
Available-for-sale debt securities:
Amortized Cost	26.8	65.3
Gross Unrealized Gains	0	0.2
Gross Unrealized Losses	(0.1)	0
Estimated Fair Value	26.7	65.5
U.S. government securities
Available-for-sale debt securities:
Amortized Cost	73.5	232.8
Gross Unrealized Gains	0.1	1
Gross Unrealized Losses	0	0
Estimated Fair Value	73.6	233.8
Total fixed income securities
Available-for-sale debt securities:
Amortized Cost	811.5	1,389
Gross Unrealized Gains	0.8	6.9
Gross Unrealized Losses	(2.2)	(0.1)
Estimated Fair Value	810.1	1,395.8
Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Amortized Cost	9.6	18.3
Gross Unrealized Gains	37.4	37.4
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 47	$ 55.7

Cash Equivalents and Investme_4

Cash Equivalents and Investments - Maturities of Fixed Income Securities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Amortized Cost
Amortized Cost	$ 821.1	$ 1,407.3
Estimated Fair Value
Total	857.1	1,451.5
Fixed income securities
Amortized Cost
Due in less than one year	354
Due between one and five years	457.5
Amortized Cost	811.5	1,389
Estimated Fair Value
Due in less than one year	354.6
Due between one and five years	455.5
Total	$ 810.1	$ 1,395.8

Cash Equivalents and Investme_5

Cash Equivalents and Investments - Narrative (Details)	12 Months Ended
Cash Equivalents and Investments - Narrative (Details)	Dec. 31, 2021USD ($)lease	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Restricted Cash and Cash Equivalents Items [Line Items]
Gross unrealized losses	$ 2,200,000
Total investments In unrealized loss position \| lease	393
Gross realized gains from available-for-sale debt securities	$ 15,300,000	$ 0	$ 0
Gross realized losses from available-for-sale debt securities	0	0	0
Equity investments, unrealized gains	0	0	0
Equity investments, unrealized losses	0	0	$ 0
Restricted cash and investments	64,100,000
Debt Securities
Restricted Cash and Cash Equivalents Items [Line Items]
Allowance for credit losses	0	$ 0
Prepaid expenses and other current assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and investments	32,200,000
Other long-term assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash and investments	$ 31,900,000

Cash Equivalents and Investme_6

Cash Equivalents and Investments - Investments in Equity Securities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments without readily determinable fair value	$ 150.1	$ 146.2
Total equity securities	573.6	718.7
Cash equivalents
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	371.5	519.8
Short-term investments
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	8.1	6.6
Inventory
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	15.1	9.9
Other long-term assets
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Total equity securities	178.9	182.4
Money market funds
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments with readily determinable fair value	382	536.6
Mutual funds
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments with readily determinable fair value	33.4	29.3
Publicly-traded equity securities
Debt Securities, Trading, and Equity Securities, FV-NI [Line Items]
Equity investments with readily determinable fair value	$ 8.1	$ 6.6

Cash Equivalents and Investme_7

Cash Equivalents and Investments - Restricted Cash and Investments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 922.5	$ 1,361.9
Total cash, cash equivalents, and restricted cash	942.7	1,383	$ 1,276.5	$ 2,505.8
Prepaid expenses and other current assets
Cash and Cash Equivalents [Line Items]
Restricted cash included in Prepaid expenses and other current assets	17.2	19.2
Other long-term assets
Cash and Cash Equivalents [Line Items]
Restricted cash included in Prepaid expenses and other current assets	$ 3	$ 1.9

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Available-for-sale debt securities:
Available-for-sale debt securities	$ 857.1	$ 1,451.5
Derivative assets:
Derivative assets	56.3	89
Cash equivalents
Available-for-sale debt securities:
Available-for-sale debt securities	47.2	333.7
Short-term investments
Available-for-sale debt securities:
Available-for-sale debt securities	307.4	405.5
Long-term investments
Available-for-sale debt securities:
Available-for-sale debt securities	455.5	656.6
Asset-backed and mortgage-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	138.6	76.7
Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	5	32.9
Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	75.8	89.3
Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	442.5	637.4
Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	12.7	4.6
Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	35.2	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	73.6	233.8
Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	47	55.7
Money market funds
Equity securities:
Equity securities	382	536.6
Publicly-traded equity securities
Equity securities:
Equity securities	8.1	6.6
Fair Value, Measurements, Recurring
Available-for-sale debt securities:
Available-for-sale debt securities	857.1	1,451.5
Equity securities:
Equity securities	423.5	572.5
Derivative assets:
Derivative assets	56.3	89
Total assets measured at fair value on a recurring basis	1,336.9	2,113
Derivative liabilities:
Derivative liabilities	(26.5)	(0.5)
Total liabilities measured at fair value on a recurring basis	(26.5)	(0.5)
Fair Value, Measurements, Recurring \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	418.8	853.5
Fair Value, Measurements, Recurring \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	315.5	412.1
Fair Value, Measurements, Recurring \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	455.5	656.6
Fair Value, Measurements, Recurring \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	23.9	37.9
Fair Value, Measurements, Recurring \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	123.2	152.9
Fair Value, Measurements, Recurring \| Other accrued liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	(14.9)	(0.3)
Fair Value, Measurements, Recurring \| Other long-term liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	(11.6)	(0.2)
Fair Value, Measurements, Recurring \| Foreign exchange contracts
Derivative assets:
Derivative assets	9.2	38
Derivative liabilities:
Derivative liabilities	(24)	(0.5)
Fair Value, Measurements, Recurring \| Interest rate contracts
Derivative assets:
Derivative assets	47.1	51
Derivative liabilities:
Derivative liabilities	(2.5)	0
Fair Value, Measurements, Recurring \| Asset-backed and mortgage-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	138.6	76.7
Fair Value, Measurements, Recurring \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	5	32.9
Fair Value, Measurements, Recurring \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	75.8	89.3
Fair Value, Measurements, Recurring \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	442.5	637.4
Fair Value, Measurements, Recurring \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	12.7	4.6
Fair Value, Measurements, Recurring \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	35.2	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	73.6	233.8
Fair Value, Measurements, Recurring \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	47	55.7
Fair Value, Measurements, Recurring \| Money market funds
Equity securities:
Equity securities	382	536.6
Fair Value, Measurements, Recurring \| Mutual funds
Equity securities:
Equity securities	33.4	29.3
Fair Value, Measurements, Recurring \| Publicly-traded equity securities
Equity securities:
Equity securities	8.1	6.6
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring
Available-for-sale debt securities:
Available-for-sale debt securities	42.3	140
Equity securities:
Equity securities	423.5	572.5
Derivative assets:
Derivative assets	0	0
Total assets measured at fair value on a recurring basis	465.8	712.5
Derivative liabilities:
Derivative liabilities	0	0
Total liabilities measured at fair value on a recurring basis	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	371.6	519.8
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	41.5	101
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	8.8	45.6
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	15.1	9.9
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	28.8	36.2
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Other accrued liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Other long-term liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Foreign exchange contracts
Derivative assets:
Derivative assets	0	0
Derivative liabilities:
Derivative liabilities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Interest rate contracts
Derivative assets:
Derivative assets	0	0
Derivative liabilities:
Derivative liabilities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Asset-backed and mortgage-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	42.3	140
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Money market funds
Equity securities:
Equity securities	382	536.6
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Mutual funds
Equity securities:
Equity securities	33.4	29.3
Quoted Prices in Active Markets For Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Publicly-traded equity securities
Equity securities:
Equity securities	8.1	6.6
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring
Available-for-sale debt securities:
Available-for-sale debt securities	767.8	1,255.8
Equity securities:
Equity securities	0	0
Derivative assets:
Derivative assets	56.3	89
Total assets measured at fair value on a recurring basis	824.1	1,344.8
Derivative liabilities:
Derivative liabilities	(26.5)	(0.5)
Total liabilities measured at fair value on a recurring basis	(26.5)	(0.5)
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	47.2	333.7
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	274	311.1
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	446.7	611
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	8.8	28
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	47.4	61
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Other accrued liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	(14.9)	(0.3)
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Other long-term liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	(11.6)	(0.2)
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Foreign exchange contracts
Derivative assets:
Derivative assets	9.2	38
Derivative liabilities:
Derivative liabilities	(24)	(0.5)
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Interest rate contracts
Derivative assets:
Derivative assets	47.1	51
Derivative liabilities:
Derivative liabilities	(2.5)	0
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Asset-backed and mortgage-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	138.6	76.7
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	5	32.9
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	75.8	89.3
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	442.5	637.4
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	12.7	4.6
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	35.2	255.6
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	26.7	65.5
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	31.3	93.8
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Money market funds
Equity securities:
Equity securities	0	0
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Mutual funds
Equity securities:
Equity securities	0	0
Significant Other Observable Remaining Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Publicly-traded equity securities
Equity securities:
Equity securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring
Available-for-sale debt securities:
Available-for-sale debt securities	47	55.7
Equity securities:
Equity securities	0	0
Derivative assets:
Derivative assets	0	0
Total assets measured at fair value on a recurring basis	47	55.7
Derivative liabilities:
Derivative liabilities	0	0
Total liabilities measured at fair value on a recurring basis	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Cash equivalents
Derivative assets:
Total assets measured at fair value on a recurring basis	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Short-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Long-term investments
Derivative assets:
Total assets measured at fair value on a recurring basis	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Prepaid expenses and other current assets
Derivative assets:
Total assets measured at fair value on a recurring basis	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Other long-term assets
Derivative assets:
Total assets measured at fair value on a recurring basis	47	55.7
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Other accrued liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Other long-term liabilities
Derivative liabilities:
Total liabilities measured at fair value on a recurring basis	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Foreign exchange contracts
Derivative assets:
Derivative assets	0	0
Derivative liabilities:
Derivative liabilities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Interest rate contracts
Derivative assets:
Derivative assets	0	0
Derivative liabilities:
Derivative liabilities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Asset-backed and mortgage-backed securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Certificates of deposit
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Commercial paper
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Corporate debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Foreign government debt securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Time deposits
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| U.S. government agency securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| U.S. government securities
Available-for-sale debt securities:
Available-for-sale debt securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Privately-held debt and redeemable preferred stock securities
Available-for-sale debt securities:
Available-for-sale debt securities	47	55.7
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Money market funds
Equity securities:
Equity securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Mutual funds
Equity securities:
Equity securities	0	0
Significant Other Unobservable Remaining Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Publicly-traded equity securities
Equity securities:
Equity securities	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	12 Months Ended
Fair Value Measurements - Narrative (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate cost	$ 821,100,000	$ 1,407,300,000
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	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	1,845,600,000	2,386,600,000
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	26,500,000	500,000
Fair Value, Measurements, Recurring \| Significant Other Unobservable Remaining Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	0	0
Fair Value, Measurements, Recurring \| Significant Other Observable Remaining Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and nonfinancial liabilities, fair value disclosure	26,500,000	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
Privately-held debt and redeemable preferred stock securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate cost	9,600,000	$ 18,300,000
Privately Held Debt And Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale, debt securities, realized gains (losses)	13,400,000
Aggregate cost	$ 9,600,000

Derivative Instruments - Notion

Derivative Instruments - Notional Amount (Details) - USD ($)	Dec. 31, 2021	Apr. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	$ 2,268,500,000		$ 1,846,200,000
Designated derivatives
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	2,123,900,000		1,672,100,000
Non-designated derivatives
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	144,600,000		174,100,000
Foreign exchange contracts \| Designated derivatives \| Cash flow hedges
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	873,900,000		722,100,000
Interest rate lock contracts \| Designated derivatives \| Cash flow hedges
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	650,000,000	$ 300,000,000	650,000,000	$ 300,000,000
Interest rate swap contracts \| Designated derivatives \| Fair value hedges
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	$ 600,000,000		$ 300,000,000

Derivative Instruments - Fair V

Derivative Instruments - Fair Value of Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Derivative assets	$ 56.3	$ 89
Derivative Liabilities	26.5	0.5
Designated derivatives
Derivative [Line Items]
Derivative assets	56.2	88.8
Derivative Liabilities	26.4	0.4
Other current assets \| Designated derivatives \| Foreign exchange contracts
Derivative [Line Items]
Derivative assets	8.7	27.8
Other current assets \| Non-designated derivatives
Derivative [Line Items]
Derivative assets	0.1	0.2
Other long-term assets \| Designated derivatives \| Foreign exchange contracts
Derivative [Line Items]
Derivative assets	0.4	10
Other long-term assets \| Designated derivatives \| Interest rate lock contracts
Derivative [Line Items]
Derivative assets	45	30.7
Other long-term assets \| Designated derivatives \| Interest rate swap contracts
Derivative [Line Items]
Derivative assets	2.1	20.3
Other accrued liabilities \| Designated derivatives \| Foreign exchange contracts
Derivative [Line Items]
Derivative Liabilities	14.8	0.2
Other accrued liabilities \| Non-designated derivatives
Derivative [Line Items]
Derivative Liabilities	0.1	0.1
Other long-term liabilities \| Designated derivatives \| Foreign exchange contracts
Derivative [Line Items]
Derivative Liabilities	9.1	0.2
Other long-term liabilities \| Designated derivatives \| Interest rate swap contracts \| Fair value hedges
Derivative [Line Items]
Derivative Liabilities	$ 2.5	$ 0

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
Derivative Instruments - Narrative (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Apr. 30, 2021
Derivatives, Fair Value [Line Items]
Reduction in derivative asset		$ 17,500,000	$ 500,000
Reduction in derivative liability		17,500,000	500,000
Notional amount of derivatives		2,268,500,000	1,846,200,000
Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Foreign currency forward contracts, amounts of loss reclassified out of AOCI		28,900,000	(9,000,000)	$ (3,800,000)
Cash flow hedges
Derivatives, Fair Value [Line Items]
Derivative instruments, gain (loss) recognized in other comprehensive income (loss), effective portion		(9,100,000)	63,500,000	(6,300,000)
Designated derivatives
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		$ 2,123,900,000	1,672,100,000
Designated derivatives \| Cash flow hedges
Derivatives, Fair Value [Line Items]
Maximum maturities of cash flow hedge derivatives		36 months
Losses expected to be reclassified into earnings within the next 12 months		$ 6,100,000
Designated derivatives \| Cash flow hedges \| Interest rate lock contracts
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		$ 650,000,000	650,000,000	$ 300,000,000	$ 300,000,000
Derivative, expiration period		9 years
Swaps designated as cash flow hedges, expected termination period	4 years
Designated derivatives \| Cash flow hedges \| Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Notional amount of derivatives		$ 873,900,000	$ 722,100,000
Minimum \| Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Maturity of foreign currency derivatives		1 month
Maximum \| Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Maturity of foreign currency derivatives		4 months

Goodwill and Purchased Intang_3

Goodwill and Purchased Intangible Assets - Goodwill Rollforward (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 3,669,600,000	$ 3,337,100,000
Additions due to business combinations	92,500,000	332,500,000
Goodwill, end of period	3,762,100,000	3,669,600,000	$ 3,337,100,000
Goodwill impairment	$ 0	$ 0	$ 0

Goodwill and Purchased Intang_4

Goodwill and Purchased Intangible Assets - Purchased Intangible Assets, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross	$ 1,059	$ 962.3
Accumulated Amortization	(765.8)	(686.7)
Accumulated Impairments and Other Charges	(57.9)	(57.9)
Net	235.3	217.7
Indefinite-lived Intangible Assets [Line Items]
Total purchased intangible assets	1,108	1,011.3
Accumulated Amortization	(765.8)	(686.7)
Accumulated Impairments and Other Charges	(57.9)	(57.9)
Net	284.3	266.7
Amortization of intangible assets	79.5	40.6	$ 34.7
Impairment of intangible assets	0	0	$ 0
IPR&D
Indefinite-lived Intangible Assets [Line Items]
Gross	49	49
Technologies and patents
Finite-Lived Intangible Assets [Line Items]
Gross	913.1	823.5
Accumulated Amortization	(660.7)	(598.2)
Accumulated Impairments and Other Charges	(55.1)	(55.1)
Net	197.3	170.2
Indefinite-lived Intangible Assets [Line Items]
Accumulated Amortization	(660.7)	(598.2)
Accumulated Impairments and Other Charges	(55.1)	(55.1)
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross	136.3	129.2
Accumulated Amortization	(98.6)	(84.4)
Accumulated Impairments and Other Charges	(2.8)	(2.8)
Net	34.9	42
Indefinite-lived Intangible Assets [Line Items]
Accumulated Amortization	(98.6)	(84.4)
Accumulated Impairments and Other Charges	(2.8)	(2.8)
Trade name
Finite-Lived Intangible Assets [Line Items]
Gross	9.6	9.6
Accumulated Amortization	(6.5)	(4.1)
Accumulated Impairments and Other Charges	0	0
Net	3.1	5.5
Indefinite-lived Intangible Assets [Line Items]
Accumulated Amortization	(6.5)	(4.1)
Accumulated Impairments and Other Charges	$ 0	$ 0

Goodwill and Purchased Intang_5

Goodwill and Purchased Intangible Assets - Estimated Future Amortization Expense Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Amount
2022	$ 74.9
2023	68.7
2024	49.2
2025	39.6
2026	2.9
Net	$ 235.3	$ 217.7

Other Financial Information - I

Other Financial Information - Inventories (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Inventory [Line Items]
Production and service materials	$ 208.6	$ 158.1
Finished goods	75.6	63.8
Total inventory	284.2	221.9
Inventory
Schedule Of Inventory [Line Items]
Total inventory	272.6	210.2
Other long-term assets
Schedule Of Inventory [Line Items]
Total inventory	$ 11.6	$ 11.7

Other Financial Information - P

Other Financial Information - Property and Equipment, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property and Equipment [Line Items]
Property and equipment, gross	$ 2,018.7	$ 2,079.2
Accumulated depreciation	(1,315.7)	(1,316.9)
Property and equipment, net	703	762.3
Depreciation expense	151	166.2	$ 184
Computers and equipment
Property and Equipment [Line Items]
Property and equipment, gross	1,023.5	1,057.5
Software
Property and Equipment [Line Items]
Property and equipment, gross	226.8	231.1
Leasehold improvements
Property and Equipment [Line Items]
Property and equipment, gross	197.6	223.8
Furniture and fixtures
Property and Equipment [Line Items]
Property and equipment, gross	46.8	49.6
Building and building improvements
Property and Equipment [Line Items]
Property and equipment, gross	269.3	256
Land and land improvements
Property and Equipment [Line Items]
Property and equipment, gross	243.5	243.5
Construction-in-process
Property and Equipment [Line Items]
Property and equipment, gross	$ 11.2	$ 17.7

Other Financial Information - W

Other Financial Information - Warranties (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Warranty Reserve [Roll Forward]
Beginning balance	$ 30.2	$ 31.4
Provisions made during the period, net	39.5	37.1
Actual costs incurred during the period	(36.7)	(38.3)
Ending balance	$ 33	$ 30.2

Other Financial Information - R

Other Financial Information - Revenue, Remaining Performance Obligations and Deferred Commissions (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Deferred commission	$ 34,900,000	$ 27,400,000
Amortization of deferred commission	189,800,000	145,900,000
Impairment loss	0	$ 0
Product
Disaggregation of Revenue [Line Items]
Contract with customer, liability, revenue recognized	74,000,000
Service
Disaggregation of Revenue [Line Items]
Contract with customer, liability, revenue recognized	$ 770,400,000

Other Financial Information -_2

Other Financial Information - Revenue, Remaining Performance Obligation (Details) $ in Millions	Dec. 31, 2021USD ($)
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 1,431.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	945.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	386.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	99.3
Product
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	135.8
Product \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 117.1
Revenue recognition expected by period, satisfaction period	1 year
Product \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 15.6
Revenue recognition expected by period, satisfaction period	2 years
Product \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 3.1
Revenue recognition expected by period, satisfaction period
Service
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 1,296
Service \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 828.7
Revenue recognition expected by period, satisfaction period	1 year
Service \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 371.1
Revenue recognition expected by period, satisfaction period	2 years
Service \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Disaggregation of Revenue [Line Items]
Revenue recognition expected by period	$ 96.2
Revenue recognition expected by period, satisfaction period

Other Financial Information - O

Other Financial Information - Other Expense, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Financial Information [Abstract]
Interest income	$ 14.9	$ 36.3	$ 79.1
Interest expense	(50.8)	(77)	(88.7)
Gain (loss) on investments, net	17.6	13.3	(3.8)
Other	1.5	(5.5)	0.9
Other expense, net	$ (16.8)	$ (32.9)	$ (12.5)

Restructuring Charges - (Detail

Restructuring Charges - (Details) - USD ($) $ in Millions	12 Months Ended
Restructuring Charges - (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 42.9	$ 68	$ 35.3
Restructuring charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges	42.9	68	35.3
Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges	13.6	62.8	21.5
Facility consolidations
Restructuring Cost and Reserve [Line Items]
Restructuring charges	8.1	5.2	2.1
Contract terminations and other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 21.2	$ 0	$ 11.7

Restructuring Charges - Narrati

Restructuring Charges - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 42.9	$ 68	$ 35.3
2021 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 42.9

Restructuring Charges - Restruc

Restructuring Charges - Restructuring Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Reserve [Roll Forward]
Charges/ (Benefits)	$ 42.9	$ 68	$ 35.3
Cash Payments	(68.4)
Other	(12.9)
Restructuring liability, ending balance	12.3
2021 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance	50.7
Charges/ (Benefits)	42.9
Restructuring liability, ending balance		50.7
2021 Restructuring Plan \| Severance
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance	50.7
Charges/ (Benefits)	13.6
Cash Payments	(63.9)
Other	1
Restructuring liability, ending balance	1.4	50.7
2021 Restructuring Plan \| Facility consolidations
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance	0
Charges/ (Benefits)	8.1
Cash Payments	0
Other	(8.1)
Restructuring liability, ending balance	0	0
2021 Restructuring Plan \| Contract terminations and other
Restructuring Reserve [Roll Forward]
Restructuring liability, beginning balance	0
Charges/ (Benefits)	21.2
Cash Payments	(4.5)
Other	(5.8)
Restructuring liability, ending balance	$ 10.9	$ 0

Debt and Financing - Schedule o

Debt and Financing - Schedule of Debt (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt	$ 1,700,000,000
Unaccreted discount and debt issuance costs	(12,900,000)	$ (16,800,000)
Hedge accounting fair value adjustment	(300,000)	20,300,000
Total	1,686,800,000	2,127,300,000
Notional amount of derivatives	2,268,500,000	1,846,200,000
Senior Notes
Debt Instrument [Line Items]
Long-term debt	$ 1,700,000,000	2,123,800,000
Senior Notes \| 4.500% fixed-rate notes ("2024 Notes")
Debt Instrument [Line Items]
Stated interest rate	4.50%
Effective interest rate	4.70%
Long-term debt	$ 0	$ 265,800,000
Senior Notes \| 4.350% fixed-rate notes ("2025-I Notes")
Debt Instrument [Line Items]
Stated interest rate	4.35%	4.35%
Effective interest rate	4.47%
Long-term debt	$ 0	$ 158,000,000
Senior Notes \| 1.200% fixed-rate notes ("2025-II Notes")
Debt Instrument [Line Items]
Stated interest rate	1.20%	1.20%
Effective interest rate	1.37%
Long-term debt	$ 400,000,000	$ 400,000,000
Senior Notes \| 3.750% fixed-rate notes ("2029 Notes")
Debt Instrument [Line Items]
Stated interest rate	3.75%
Effective interest rate	3.86%
Long-term debt	$ 500,000,000	$ 500,000,000
Senior Notes \| 2.000% fixed-rate notes ("2030 Notes")
Debt Instrument [Line Items]
Stated interest rate	2.00%	2.00%
Effective interest rate	2.12%
Long-term debt	$ 400,000,000	$ 400,000,000
Senior Notes \| 5.950% fixed-rate notes ("2041 Notes")
Debt Instrument [Line Items]
Stated interest rate	5.95%
Effective interest rate	6.03%
Long-term debt	$ 400,000,000	400,000,000
Designated derivatives
Debt Instrument [Line Items]
Notional amount of derivatives	2,123,900,000	1,672,100,000
Fair value hedges \| Interest rate swap contracts \| Designated derivatives
Debt Instrument [Line Items]
Notional amount of derivatives	$ 600,000,000	$ 300,000,000

Debt and Financing - Narrative

Debt and Financing - Narrative (Details) - USD ($)	1 Months Ended			12 Months Ended
Debt and Financing - Narrative (Details) - USD ($)	Jan. 31, 2021	Dec. 31, 2020	Apr. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Repayment of debt				$ 423,800,000	$ 376,200,000	$ 950,000,000
Loss on extinguishment of debt		$ 55,000,000		60,600,000	55,000,000	15,300,000
Sale of receivables				31,900,000	57,500,000	64,000,000
Proceeds from sale and collection of receivables				32,500,000	57,400,000	$ 69,700,000
Receivables from sale of receivables		3,900,000		$ 3,200,000	3,900,000
Minimum
Debt Instrument [Line Items]
Number of days due from receivable				1 day
Maximum
Debt Instrument [Line Items]
Number of days due from receivable				90 days
Senior Notes
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 60,600,000
Principal redemption amount	482,100,000
Senior Notes \| 1.200% fixed-rate notes ("2025-II Notes")
Debt Instrument [Line Items]
Principal amount		$ 400,000,000			$ 400,000,000
Stated interest rate		1.20%		1.20%	1.20%
Senior Notes \| 2.000% fixed-rate notes ("2030 Notes")
Debt Instrument [Line Items]
Principal amount		$ 400,000,000			$ 400,000,000
Stated interest rate		2.00%		2.00%	2.00%
Senior Notes \| 4.500% fixed-rate notes (2024 Notes) - Issued March 2014
Debt Instrument [Line Items]
Stated interest rate		4.50%			4.50%
Repayment of debt					$ 500,000,000
Debt redemption, amount		$ 234,200,000			$ 234,200,000
Senior Notes \| 4.350% fixed-rate notes ("2025-I Notes")
Debt Instrument [Line Items]
Stated interest rate		4.35%		4.35%	4.35%
Repayment of debt					$ 300,000,000
Debt redemption, amount		$ 142,000,000			$ 142,000,000
Senior Notes \| 4.500% fixed-rate notes ("2024 Notes")
Debt Instrument [Line Items]
Stated interest rate				4.50%
Principal redemption amount	265,800,000
Senior Notes \| Fixed Rate Note Due June 2025
Debt Instrument [Line Items]
Principal redemption amount	$ 158,000,000
Senior Notes \| Fixed Rate Note Due 2025 And Fixed Rate Note Due 2029
Debt Instrument [Line Items]
Debt instrument, redemption price, percent				100.00%
Repurchase price percentage related to change in control				101.00%
Line of Credit
Debt Instrument [Line Items]
Amounts outstanding				$ 0
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt, term			5 years
Maximum borrowing capacity			$ 500,000,000
Additional borrowing capacity			$ 200,000,000
Maximum leverage ratio			3
Maximum leverage ratio, if acquisition is consummated			3.5
Interest coverage ratio			3
Line of Credit \| Revolving Credit Facility \| Federal Funds Rate \| Variable Rate Component, Federal Funds
Debt Instrument [Line Items]
Basis spread on variable rate			0.50%
Line of Credit \| Revolving Credit Facility \| ICE Benchmark Administration Settlement Rate \| Variable Rate Component, ICE Benchmark Administration Settlement Rate
Debt Instrument [Line Items]
Basis spread on variable rate			1.00%
Line of Credit \| Revolving Credit Facility \| Minimum \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate			0.00%
Line of Credit \| Revolving Credit Facility \| Minimum \| Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate			0.91%
Line of Credit \| Revolving Credit Facility \| Maximum \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate			0.375%
Line of Credit \| Revolving Credit Facility \| Maximum \| Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate			1.375%

Debt and Financing - Schedule_2

Debt and Financing - Schedule of Aggregate Debt Maturities (Details) $ in Millions	Dec. 31, 2021USD ($)
Debt Instruments [Abstract]
2022	$ 0
2023	0
2024	0
2025	400
2026	0
Thereafter	1,300
Total	$ 1,700

Equity - Stock Repurchase Activ

Equity - Stock Repurchase Activities (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Oct. 26, 2021	Jul. 27, 2021	Apr. 27, 2021	Jan. 28, 2021	Oct. 31, 2019	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Dividends
Per Share (in dollars per share)	$ 0.20	$ 0.20	$ 0.20	$ 0.20		$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.80	$ 0.80	$ 0.76
Amount																		$ 259.1	$ 264.1	$ 260.1
Stock Repurchases
Amount																		$ 443.5	421.1	$ 514.9
Remaining forward contract, value																			$ 40
Stock Repurchase Program 2018
Stock Repurchases
Shares (in shares)																		15.7	17.9	20.1
Average price per share (in dollars per share)																		$ 27.56	$ 23.47	$ 25.36
Amount					$ 160													$ 433.3	$ 375	$ 550
Tax Withholding Amount																		10.2	6.2	5
Amount																		$ 702.6	$ 645.3	$ 815.1

Equity - Narrative (Details)

Equity - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions	Oct. 26, 2021	Jul. 27, 2021	Apr. 27, 2021	Jan. 28, 2021	Jan. 31, 2020	Oct. 31, 2019	Apr. 30, 2019	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jan. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Payments of cash dividends (in dollars per share)	$ 0.20	$ 0.20	$ 0.20	$ 0.20				$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.19	$ 0.19	$ 0.19	$ 0.19		$ 0.80	$ 0.80	$ 0.76
Cash dividends																					$ 259,100,000	$ 264,100,000	$ 260,100,000
Stock repurchased under ASR, market price (in dollars per share)						$ 25.15	$ 25.79
Payment to repurchase stock																					443,500,000	381,100,000	554,900,000
Amount																					$ 443,500,000	$ 421,100,000	$ 514,900,000
Stock repurchased and retired (in dollars per share)					$ 24.44
Stock Repurchase Program 2018
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount						$ 3,000,000,000																		$ 2,000,000,000
Stock repurchase program, increased amount						1,000,000,000
Stock repurchased (in shares)							11.6														15.7
Repurchase and retirement of common stock (in shares)																					15.7	17.9	20.1
Amount						160,000,000															$ 433,300,000	$ 375,000,000	$ 550,000,000
Stock repurchased average cost (in dollars per share)																					$ 27.56
Stock repurchase program, authorized funds remaining								$ 900,000,000													$ 900,000,000
Accelerated Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount						200,000,000	$ 300,000,000
Payment to repurchase stock						$ 200,000,000
Repurchase and retirement of common stock (in shares)					1.8	6.4														8.2

Equity - Accumulated Other Comp

Equity - Accumulated Other Comprehensive Income (loss), Net of Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Balance	$ 4,543.5	$ 4,610.6	$ 4,823.2
Other comprehensive income (loss) before reclassifications	(31.3)	67.8	(5.4)
Amount reclassified from accumulated other comprehensive income (loss)	(26.4)	6.3	5.1
Other comprehensive (loss) income, net	(57.7)	74.1	(0.3)
Balance	4,316.9	4,543.5	4,610.6
Other comprehensive income (loss)	28.9	0	0
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Balance	55.6	(18.5)	(18.2)
Other comprehensive (loss) income, net	(57.7)	74.1	(0.3)
Balance	(2.1)	55.6	(18.5)
Unrealized Gains/Losses on Available-for- Sale Debt Securities
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Balance	34.1	29.7	25.5
Other comprehensive income (loss) before reclassifications	(5)	5.7	4.6
Amount reclassified from accumulated other comprehensive income (loss)	(1.2)	(1.3)	(0.4)
Other comprehensive (loss) income, net	(6.2)	4.4	4.2
Balance	27.9	34.1	29.7
Unrealized Gain/Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Balance	57.7	(4.3)	(0.9)
Other comprehensive income (loss) before reclassifications	(13.5)	54.4	(8.9)
Amount reclassified from accumulated other comprehensive income (loss)	(25.2)	7.6	5.5
Other comprehensive (loss) income, net	(38.7)	62	(3.4)
Balance	19	57.7	(4.3)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]
Balance	(36.2)	(43.9)	(42.8)
Other comprehensive income (loss) before reclassifications	(12.8)	7.7	(1.1)
Amount reclassified from accumulated other comprehensive income (loss)	0	0	0
Other comprehensive (loss) income, net	(12.8)	7.7	(1.1)
Balance	$ (49)	$ (36.2)	$ (43.9)

Employee Benefit Plans - Equity

Employee Benefit Plans - Equity Incentive Plans (Details)	1 Months Ended			12 Months Ended
Employee Benefit Plans - Equity Incentive Plans (Details)	May 31, 2020shares	May 31, 2019shares	May 31, 2017shares	Dec. 31, 2021USD ($)offeringPeriodshares	Dec. 31, 2020shares	May 31, 2015shares
Share-Based Compensation Plans
ESPP, offering period				24 months
ESPP, number of offering period \| offeringPeriod				4
ESPP, purchase period				6 months
ESPP, purchase price				85.00%
Common stock - shares issued (in shares)				321,600,000	327,700,000
Common shares outstanding from equity awards through acquisition (in shares)				5,800,000
Apstra And WiteSand Acquisitions
Share-Based Compensation Plans
Common shares outstanding from equity awards through acquisition (in shares)				2,500,000
128 Technology
Share-Based Compensation Plans
Common shares outstanding from equity awards through acquisition (in shares)					3,900,000
Equity Incentive Plan 2015
Share-Based Compensation Plans
Number of shares authorized (in shares)						38,000,000
Additional shares authorized (in shares)		3,700,000	23,000,000	0
Aggregate shares subject to outstanding equity awards (in shares)				16,500,000
Number of shares available for future issuance (in shares)				5,100,000	12,100,000
Equity Incentive Plan 1996 and 2006
Share-Based Compensation Plans
Maximum additional shares expired, unexercised, canceled (in shares)						29,000,000
Employee Stock Purchase Plan 2008
Share-Based Compensation Plans
Number of shares authorized (in shares)				43,000,000
Additional shares authorized (in shares)	8,000,000
Number of shares available for future issuance (in shares)				8,800,000
Discount on share purchase price for purchases made under ESPP				15.00%
Periodic payroll deduction - percentage of base salary				10.00%
ESPP individual purchase limits (in shares)				6,000
Period for share purchases under ESPP				12 months
ESPP individual purchase limits \| $				$ 25,000
Period for ESPP purchases				1 year
Common stock - shares issued (in shares)				34,200,000

Employee Benefit Plans - RSU, R

Employee Benefit Plans - RSU, RSA, and PSA Activities (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Oct. 26, 2021	Jul. 27, 2021	Apr. 27, 2021	Jan. 28, 2021	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Weighted Average Grant-Date Fair Value per Share
Payments of cash dividends (in dollars per share)	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.80	$ 0.80	$ 0.76
Restricted Stock Units (RSU) and Restricted Stock \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																	3 years
Performance Shares (PSAs)
Number of Shares
Granted (in shares)																	1.5
Performance Shares (PSAs) \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																	2 years
Performance Shares (PSAs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period																	3 years
RSUs, RSAs, and PSAs
Number of Shares
Balance at beginning of period (in shares)								19.9									19.9
Granted (in shares)																	10.2
Awards assumed upon the acquisition of Apstra (in shares)																	2.5
Vested (in shares)																	(7.8)
Canceled (in shares)																	(2.6)
Balance at end of period (in shares)					22.2				19.9								22.2	19.9
Vested and expected-to-vest RSUs, RSAs and PSAs, number of shares at (in shares)					19.7												19.7
Weighted Average Grant-Date Fair Value per Share
Balance at beginning of period (in dollars per share)								$ 23.05									$ 23.05
Granted (in dollars per share)																	26.19
Awards assumed upon the acquisition of Apstra (in dollars per share)																	26.28
Vested (in dollars per share)																	23.66
Canceled (in dollars per share)																	23.91
Balance at end of period (in dollars per share)					$ 24.55				$ 23.05								24.55	$ 23.05
Vested and expected-to-vest RSUs, RSAs and PSA, weighted average grant date fair value (in dollars per share)																	$ 24.96
Weighted Average Remaining Contractual Term (In Years)																	1 year 3 months 18 days
Vested and expected to vest RSUs, RSAs, and PSAs, weighted average remaining contractual term																	1 year 3 months 18 days
Aggregate Intrinsic Value					$ 791.3												$ 791.3
Vested and expected-to-vest RSUs, RSAs and PSA, aggregate intrinsic value																	$ 703.7
Weighted-average grant-date fair value, RSUs, RSAs, PSUs granted, assumed or substituted (in dollars per share)																	$ 26.21	$ 21.59	$ 25.26
Fair value of RSUs, RSAs and PSAs																	$ 184.2	$ 174.7	$ 170
Service-based RSUs
Number of Shares
Granted (in shares)																	8.2
Marked-based RSUs
Number of Shares
Granted (in shares)																	0.5

Employee Benefit Plans - Shares

Employee Benefit Plans - Shares Available For Grant (Details) - Equity Incentive Plan 2015 - shares	1 Months Ended		12 Months Ended
	May 31, 2019	May 31, 2017	Dec. 31, 2021
Number of Shares
Balance as of beginning of period (in shares)			12,100,000
Additional shares authorized (in shares)	3,700,000	23,000,000	0
RSUs and PSAs granted (in shares)			(10,500,000)
RSUs and PSAs canceled (in shares)			3,500,000
Balance as of end of period (in shares)			5,100,000
Canceled shares returned to the share reserve (in shares)			2,200,000

Employee Benefit Plans - Employ

Employee Benefit Plans - Employee Stock Purchase Plan and Valuation Assumptions (Details) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Stock Purchase Plan
Estimates of Fair Value
Volatility	32.00%	31.00%	27.00%
Risk-free interest rate	0.10%	0.80%	2.10%
Expected life (years)	1 year 3 months 18 days	1 year 3 months 18 days	1 year 2 months 12 days
Dividend yield	3.00%	3.30%	2.90%
Weighted-average fair value per share (in dollars per share)	$ 6.96	$ 6.34	$ 6.65
Market-based RSUs
Estimates of Fair Value
Volatility	30.00%	25.00%	25.00%
Risk-free interest rate	0.20%	1.30%	2.40%
Dividend yield	3.40%	3.30%	2.80%
Weighted-average fair value per share (in dollars per share)	$ 30.70	$ 26.32	$ 27.32
Employee Stock Purchase Plan 2008
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares purchased through ESPP (in shares)	2.8	2.7	2.4
Average exercise price of shares purchased through ESPP (in dollars per share)	$ 19.81	$ 19.59	$ 22.04

Employee Benefit Plans - Share-

Employee Benefit Plans - Share-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 222.6	$ 189.6	$ 202.2
Stock options
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	9.3	7.3	7.7
RSUs, RSAs, and PSAs
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	196.2	162.6	176.5
ESPP Purchase Rights
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	17.1	19.7	18
Cost of revenues - Product
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	5.3	5.4	5.7
Cost of revenues - Service
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	18.2	15.8	17.3
Research and development
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	93.1	78.8	94
Sales and marketing
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	65.9	58.2	56
General and administrative
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 40.1	$ 31.4	$ 29.2

Employee Benefit Plans - Shar_2

Employee Benefit Plans - Share-Based Compensation Expense Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Company recognized tax benefits on total stock-based compensation expense	$ 28.2	$ 23.5	$ 29.6
Tax benefit realized related to awards vested or exercised during the period	31.7	$ 21.7	$ 30.6
Unrecognized compensation cost	$ 357.4
Weighted average period that unrecognized compensation cost will be recognized	1 year 9 months 18 days

Employee Benefit Plans - 401(k)

Employee Benefit Plans - 401(k) plan, Deferred Compensation Plan and Non-US Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Benefit Textuals [Abstract]
Employee contribution matched	30.00%
Matching contributions to plan	$ 22.3	$ 22	$ 20.2
NQDC
Employee Benefit Textuals [Abstract]
Deferred compensation liability	33.3	29.3
Investment	33.3	29.3
Other accrued liabilities \| NQDC
Employee Benefit Textuals [Abstract]
Deferred compensation liability	4.4	3.1
Other long-term liabilities \| NQDC
Employee Benefit Textuals [Abstract]
Deferred compensation liability	28.9	26.2
Inventory \| NQDC
Employee Benefit Textuals [Abstract]
Investment	4.4	3.1
Other long-term assets \| NQDC
Employee Benefit Textuals [Abstract]
Investment	$ 28.9	$ 26.2

Segments - Revenue by Product (

Segments - Revenue by Product (Details) $ in Millions	12 Months Ended
Segments - Revenue by Product (Details) $ in Millions	Dec. 31, 2021USD ($)segment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment	1
Net revenues	$ 4,735.4	$ 4,445.1	$ 4,445.4
Automated WAN Solutions
Segment Reporting Information [Line Items]
Net revenues	1,665	1,622.2	1,604.4
Cloud-Ready Data Center
Segment Reporting Information [Line Items]
Net revenues	727.1	677.1	726.5
AI-Driven Enterprise
Segment Reporting Information [Line Items]
Net revenues	830.4	656.2	613.8
Hardware Maintenance and Professional Services
Segment Reporting Information [Line Items]
Net revenues	$ 1,512.9	$ 1,489.6	$ 1,500.7

Segments - Revenue (Details)

Segments - Revenue (Details) - USD ($) $ in Millions	12 Months Ended
Segments - Revenue (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net Revenues [Abstract]
Net revenues	$ 4,735.4	$ 4,445.1	$ 4,445.4
Cloud
Net Revenues [Abstract]
Net revenues	1,228	1,081.2	1,059.8
Service Provider
Net Revenues [Abstract]
Net revenues	1,839.1	1,761.7	1,827.8
Enterprise
Net Revenues [Abstract]
Net revenues	$ 1,668.3	$ 1,602.2	$ 1,557.8

Segments - Geographical (Detail

Segments - Geographical (Details) - USD ($) $ in Millions	12 Months Ended
Segments - Geographical (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net Revenues by Geographic Region [Line Items]
Net revenues	$ 4,735.4	$ 4,445.1	$ 4,445.4
Property and equipment, net	703	762.3
Total Americas
Net Revenues by Geographic Region [Line Items]
Net revenues	2,649.1	2,445.1	2,518
United States
Net Revenues by Geographic Region [Line Items]
Net revenues	2,426.9	2,233.9	2,299.8
Property and equipment, net	623.4	667.4
Other
Net Revenues by Geographic Region [Line Items]
Net revenues	222.2	211.2	218.2
Europe, Middle East, and Africa
Net Revenues by Geographic Region [Line Items]
Net revenues	1,314.5	1,233.8	1,215.3
Asia Pacific
Net Revenues by Geographic Region [Line Items]
Net revenues	771.8	766.2	$ 712.1
International
Net Revenues by Geographic Region [Line Items]
Property and equipment, net	$ 79.6	$ 94.9

Income Taxes - Components of Pr

Income Taxes - Components of Pretax Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Components of income before provision for income taxes and noncontrolling interest
Domestic	$ 264.6	$ 204.2	$ 296.2
Foreign	45.5	61	118.2
Income before income taxes	310.1	265.2	414.4
Current provision (benefit):
Federal	63.4	73.4	6.2
States	15.9	20.3	14.4
Foreign	48.2	(21.6)	48.5
Total current provision (benefit)	127.5	72.1	69.1
Deferred (benefit) provision:
Federal	(54.3)	(58.7)	0.8
States	(4.1)	(6.6)	2.8
Foreign	(11.7)	0.6	(3.3)
Total deferred (benefit) provision	(70.1)	(64.7)	0.3
Total provision (benefit) for income taxes	57.4	7.4	69.4
Income tax reconciliation
Expected provision at statutory rate	65.1	55.7	87
State taxes, net of federal benefit	6.5	8.7	9.4
Foreign income at different tax rates	(0.2)	(5.9)	1.8
R&D tax credits	(16.6)	(16.4)	(18.8)
Share-based compensation	(2.2)	9	3.8
Non-deductible compensation	4.2	3.5	3.3
Temporary differences not currently benefited	0	(0.9)	12.9
Recognition of previously unrecognized tax benefits	0	(63.7)	(25.4)
Cost sharing adjustment- Altera	0	20.1	0
Lapses in federal statutes of limitations	0	0	(7.5)
Other	0.6	(2.7)	2.9
Total provision (benefit) for income taxes	$ 57.4	$ 7.4	$ 69.4

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Recognition of previously unrecognized tax benefits	$ 0	$ 63.7	$ 25.4
Cost sharing adjustment- Altera	0	20.1	0
Valuation allowance	300.9	261.5
Increase (decrease) in DTA valuation allowance	39.4	12.1
Undistributed earnings of foreign subsidiaries	83.1
Additional income tax expense related to undistributed earnings	16.9
Unrecognized tax benefits	113.4	116	151.3	$ 178.1
Unrecognized tax benefits that would impact effective tax rate	110.5
Unrecognized tax benefits, penalties and interest	2.7	20.7	2.8
Reductions in unrecognized tax benefits (up to)	3.6	52	3.3
Incremental tax benefit from stock-based compensation	2.2	(9)	(3.8)
Minimum
Income Tax Contingency [Line Items]
Reductions in unrecognized tax benefits (up to)	7.3
Other long-term liabilities
Income Tax Contingency [Line Items]
Interest and penalties accrued related to unrecognized tax benefits	8.1	$ 5.3	$ 29.9
Federal
Income Tax Contingency [Line Items]
Valuation allowance	2
Net operating loss carry-forwards	205.5
Tax credit carry-forwards	6.6
State and Local Jurisdiction
Income Tax Contingency [Line Items]
Valuation allowance	288.7
State and Local Jurisdiction \| CALIFORNIA
Income Tax Contingency [Line Items]
Net operating loss carry-forwards	197.9
State and Local Jurisdiction \| Other States
Income Tax Contingency [Line Items]
Net operating loss carry-forwards	144.6
Foreign Tax Authority
Income Tax Contingency [Line Items]
Valuation allowance	10.2
California Deferred Tax Assets \| State and Local Jurisdiction
Income Tax Contingency [Line Items]
Net operating loss carry-forwards	197.9
Tax credit carry-forwards	$ 292.4

Income Taxes - Deferred Taxes (

Income Taxes - Deferred Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carry-forwards	$ 72.5	$ 48.2
Research and other credit carry-forwards	272.2	252.8
Deferred revenue	47.7	43.4
Share-based compensation	17.9	15
Capitalized R&D expenditure	102	60.5
Reserves and accruals not currently deductible	61	43.5
Operating lease liabilities	45.4	51.3
Other	9.9	10.6
Total deferred tax assets	628.6	525.3
Valuation allowance	(300.9)	(261.5)
Deferred tax assets, net of valuation allowance	327.7	263.8
Deferred tax liabilities:
Property and equipment basis differences	(1.3)	(20.1)
Purchased intangible assets	(56.5)	(45.6)
Unremitted foreign earnings	(25.5)	(25.5)
Net unrealized gain	(21)	(21.1)
Operating lease assets	(39.9)	(44.9)
Total deferred tax liabilities	(144.2)	(157.2)
Net deferred tax assets	$ 183.5	$ 106.6

Income Taxes - Income Tax Conti

Income Taxes - Income Tax Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 116	$ 151.3	$ 178.1
Tax positions related to current year:
Additions	7.7	5.3	5.9
Tax positions related to prior years:
Additions	3.3	18.1	0.8
Reductions	(3.6)	(52)	(3.3)
Settlements	(9.4)	(1.8)	(22.5)
Lapses in statutes of limitations	(0.6)	(4.9)	(7.7)
Balance at end of year	$ 113.4	$ 116	$ 151.3

Net Income per Share (Details)

Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net income	$ 252.7	$ 257.8	$ 345
Denominator:
Weighted-average shares used to compute basic net income per share (in shares)	324.4	330.4	343.2
Dilutive effect of employee stock awards (in shares)	7.2	4.8	5
Weighted-average shares used to compute diluted net income per share (in shares)	331.6	335.2	348.2
Net income per share:
Basic (in dollars per share)	$ 0.78	$ 0.78	$ 1.01
Diluted (in dollars per share)	$ 0.76	$ 0.77	$ 0.99
Anti-dilutive shares (in shares)	0.5	5.3	4.7

Commitments and Contingencies -

Commitments and Contingencies - Unconditional Purchase Obligations (Details) $ in Millions	Dec. 31, 2021USD ($)
Unconditional Purchase Obligations
2022	$ 61
2023	43.9
2024	16.5
2025	7.3
2026	0.6
Total	$ 129.3

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Guarantor Obligations [Line Items]
Accrued estimated carrying charges	$ 19.8
Long-term debt	1,686.8	$ 2,127.3
Income taxes payable	250.6
Unrecognized tax benefits	113.4	116	$ 151.3	$ 178.1
Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, current carrying value	1.9	6.7
Financing guarantees, bank guarantees, and standby letters of credit
Guarantor Obligations [Line Items]
Guarantor obligations, current carrying value	2.4	$ 29
Master Service Agreement
Guarantor Obligations [Line Items]
Expected payment	$ 145.3
Facilities \| Minimum
Guarantor Obligations [Line Items]
Lease term	1 year
Facilities \| Maximum
Guarantor Obligations [Line Items]
Lease term	10 years
Equipment \| Minimum
Guarantor Obligations [Line Items]
Lease term	1 year
Equipment \| Maximum
Guarantor Obligations [Line Items]
Lease term	4 years
Long-term Income Taxes
Guarantor Obligations [Line Items]
Unrecognized tax benefits	$ 79.9

Commitments and Contingencies_3

Commitments and Contingencies - Lease Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 57.4	$ 50.8
Variable lease cost	11.5	13.4
Total lease cost	68.9	64.2
Operating cash outflows from operating leases	57.8	54.2
ROU assets obtained in exchange for new operating lease liabilities	$ 29.7	$ 54.7
Weighted average remaining lease term (years)	4 years 7 months 6 days	4 years 10 months 24 days
Weighted average discount rate	3.30%	3.70%

Commitments and Contingencies_4

Commitments and Contingencies - Future Operating Lease Payments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Amount
2022	$ 48.7
2023	47.6
2024	43.1
2025	34.6
2026	14.3
Thereafter	15.3
Total lease payments	203.6
Less: interest	(14.2)
Total	189.4
Balance Sheet Information
Other accrued liabilities	47.2
Long-term operating lease liabilities	$ 142.2	$ 163.5

Commitments and Contingencies_5

Commitments and Contingencies - Purchase Commitments (Details) $ in Millions	Dec. 31, 2021USD ($)
Purchase Commitments
2022	$ 2,094.3
2023	523
2024	14.4
2025	0.5
Total	$ 2,632.2

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, shares in Millions	Mar. 22, 2022	Jan. 27, 2022	Oct. 26, 2021	Jul. 27, 2021	Apr. 27, 2021	Jan. 28, 2021	Feb. 11, 2022	Oct. 31, 2019	Apr. 30, 2019	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 31, 2018
Subsequent Event [Line Items]
Payments of cash dividends (in dollars per share)			$ 0.20	$ 0.20	$ 0.20	$ 0.20				$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.19	$ 0.19	$ 0.19	$ 0.19	$ 0.80	$ 0.80	$ 0.76
Amount																						$ 443,500,000	$ 421,100,000	$ 514,900,000
Forecast
Subsequent Event [Line Items]
Payments of cash dividends (in dollars per share)	$ 0.21
Stock Repurchase Program 2018
Subsequent Event [Line Items]
Stock repurchased (in shares)									11.6													15.7
Amount								$ 160,000,000														$ 433,300,000	$ 375,000,000	$ 550,000,000
Repurchase and retirement of common stock (in shares)																						15.7	17.9	20.1
Stock repurchase program, authorized amount								$ 3,000,000,000																	$ 2,000,000,000
Subsequent Event
Subsequent Event [Line Items]
Cash dividends declared per share of common stock (in dollars per share)		$ 0.21
Subsequent Event \| Stock Repurchase Program 2018
Subsequent Event [Line Items]
Stock repurchased (in shares)							2.6
Amount							$ 91,100,000
Price paid per share (in dollars per share)							$ 34.75
Repurchase and retirement of common stock (in shares)							2
Stock repurchase program, authorized amount							$ 800,000,000

Schedule II- Valuation and Qu_2

Schedule II- Valuation and Qualifying Account - Allowance for Doubtful Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 9.9	$ 5.5	$ 4.9
Charged to (Reversed from) Costs and Expenses	(3.2)	4.4	1.7
Write-offs, Net of Recoveries	0	0	(1.1)
Balance at End of Year	$ 6.7	$ 9.9	$ 5.5

Schedule_II_- Valuation and Qua

Schedule II - Valuation and Qualifying Account - Sales Return Reserve (Details) - Sales Return Reserve - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 28.4	$ 24.8	$ 32.7
Charged as a Reduction in Revenues	57.6	60.7	59.5
Used	(54.6)	(57.1)	(67.4)
Balance at End of Year	$ 31.4	$ 28.4	$ 24.8