Cognizant Technology Solutions (CTSH) 10-K 12 Feb 21 2020 FY Annual report Financial data

Cover Cover

Cover Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 05, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	0-24429
Entity Registrant Name	COGNIZANT TECHNOLOGY SOLUTIONS CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3728359
Entity Address, Address Line One	300 Frank W. Burr Blvd.
Entity Address, City or Town	Teaneck
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07666
City Area Code	201
Local Phone Number	801-0233
Title of 12(b) Security	Class A Common Stock, $0.01 par value per share
Trading Symbol	CTSH
Security Exchange Name	NASDAQ
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			$ 30.8
Entity Common Stock, Shares Outstanding		530,614,258
Documents Incorporated by Reference	The following documents are incorporated by reference into the Annual Report on Form 10-K: Portions of the registrant’s definitive Proxy Statement for its 2021 Annual Meeting of Stockholders are incorporated by reference into Part III of this Report.
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0001058290

Consolidated Statements Of Fina

Consolidated Statements Of Financial Position - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 2,680	$ 2,645
Short-term investments	44	779
Trade accounts receivable, net	3,087	3,256
Other current assets	1,040	931
Total current assets	6,851	7,611
Property and equipment, net	1,251	1,309
Operating lease assets, net	1,013	926
Goodwill	5,031	3,979
Intangible assets, net	1,046	1,041
Deferred income tax assets, net	445	585
Long-term investments	440	17
Other noncurrent assets	846	736
Total assets	16,923	16,204
Liabilities and Stockholders' Equity
Accounts payable	389	239
Deferred revenue	383	313
Short-term debt	38	38
Operating lease liabilities	211	202
Accrued expenses and other current liabilities	2,519	2,191
Total current liabilities	3,540	2,983
Deferred revenue, noncurrent	36	23
Operating lease liabilities, noncurrent	846	745
Deferred income tax liabilities, net	206	35
Long-term debt	663	700
Long-term income taxes payable	428	478
Other noncurrent liabilities	368	218
Total liabilities	6,087	5,182
Commitments and contingencies (See Note 15)
Stockholders' Equity:
Preferred stock, $0.10 par value, 15 shares authorized, none issued	0	0
Class A common stock, $0.01 par value, 1,000 shares authorized, 530 and 548 shares issued and outstanding at December 31, 2020 and 2019, respectively	5	5
Additional paid-in capital	32	33
Retained earnings	10,689	11,022
Accumulated other comprehensive income (loss)	110	(38)
Total stockholders’ equity	10,836	11,022
Total liabilities and stockholders’ equity	$ 16,923	$ 16,204

Consolidated Statements Of Fi_2

Consolidated Statements Of Financial Position (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, shares authorized	15,000,000	15,000,000
Preferred stock, issued	0	0
Class A common stock, par value	$ 0.01	$ 0.01
Class A common stock, shares authorized	1,000,000,000	1,000,000,000
Class A common stock, shares issued	530,000,000	548,000,000
Class A common stock, shares outstanding	530,000,000	548,000,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Depreciation, Depletion and Amortization	$ 552	$ 507	$ 460
Revenues	16,652	16,783	16,125
Operating expenses:
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)	10,671	10,634	9,838
Selling, general and administrative expenses	3,100	2,972	3,007
Income from operations	2,114	2,453	2,801
Other income (expense), net:
Interest income	119	176	177
Interest expense	(24)	(26)	(27)
Foreign currency exchange gains (losses), net	(116)	(65)	(152)
Other, net	3	5	(2)
Total other income (expense), net	(18)	90	(4)
Income before provision for income taxes	2,096	2,543	2,797
Provision for income taxes	(704)	(643)	(698)
Income (loss) from equity method investments	0	(58)	2
Net income	$ 1,392	$ 1,842	$ 2,101
Basic earnings per share	$ 2.58	$ 3.30	$ 3.61
Diluted earnings per share	$ 2.57	$ 3.29	$ 3.60
Weighted average number of common shares outstanding—Basic	540	559	582
Dilutive effect of shares issuable under stock-based compensation plans	1	1	2
Weighted average number of common shares outstanding—Diluted	541	560	584
Restructuring Charges	$ 215	$ 217	$ 19

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 1,392	$ 1,842	$ 2,101
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	559	526	498
Deferred income taxes	184	(306)	8
Share-based Payment Arrangement, Noncash Expense	232	217	267
Other	119	119	125
Changes in assets and liabilities:
Trade accounts receivable	264	37	(365)
Other current and noncurrent assets	73	159	(8)
Accounts payable	109	8	(4)
Deferred revenue, current and noncurrent	65	56	(86)
Other current and noncurrent liabilities	302	(159)	56
Net cash provided by operating activities	3,299	2,499	2,592
Cash flows from investing activities:
Purchases of property and equipment	(398)	(392)	(377)
Purchases of available-for-sale investment securities	0	(333)	(1,630)
Proceeds from maturity or sale of available-for-sale investment securities	0	2,107	1,838
Purchases of held-to-maturity investment securities	(202)	(693)	(1,363)
Proceeds from maturity of held-to-maturity investment securities	467	1,498	1,164
Purchases of other investments	(531)	(483)	(513)
Proceeds from maturity or sale of other investments	549	501	365
Payments for business combinations, net of cash acquired	(1,123)	(617)	(1,111)
Net cash (used in) provided by investing activities	(1,238)	1,588	(1,627)
Cash flows from financing activities:
Issuance of common stock under stock-based compensation plans	142	159	181
Repurchases of common stock	(1,621)	(2,247)	(1,261)
Repayment of term loan borrowings and finance lease and earnout obligations	(50)	(28)	(91)
Proceeds from borrowing under the revolving credit facility	1,740	0	0
Repayment of notes outstanding under the revolving credit facility	1,740	0	0
Net repayments in notes outstanding under the revolving credit facility	0	0	(75)
Proceeds from debt modification	0	0	25
Debt issuance costs	0	0	(4)
Dividends paid	(480)	(453)	(468)
Net cash (used in) financing activities	(2,009)	(2,569)	(1,693)
Effect of exchange rate changes on cash and cash equivalents	(17)	(34)	(36)
Increase (decrease) in cash and cash equivalents	35	1,484	(764)
Cash and cash equivalents, beginning of year	2,645	1,161	1,925
Cash and cash equivalents, end of year	2,680	2,645	1,161
Supplemental information:
Cash paid for income taxes during the year	745	870	597
Cash interest paid during the year	$ 25	$ 25	$ 21

Consolidated Statements Of Stoc

Consolidated Statements Of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated other comprehensive income (loss):	Accumulated other comprehensive income (loss):Cumulative Effect, Period of Adoption, Adjustment [Member]
AOCI, beginning balance at Dec. 31, 2017	$ 10,669	$ 121	$ 6	$ 49	$ 10,544	$ 122	$ 70	$ (1)
Beginning balance, shares at Dec. 31, 2017			588
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,101				2,101
Other comprehensive income (loss)	(183)						(183)
Common stock issued, stock-based compensation plans	181			181
Common stock issued, stock based compensation plans and other, shares			6
Stock-based compensation expense	267			267
Repurchases of common stock	(1,261)			(450)	(811)
Repurchases of common stock, shares			(17)
Dividends declared	(471)				(471)
AOCI, ending balance at Dec. 31, 2018	11,424	2	$ 6	47	11,485	2	(114)	$ (1)
Ending balance, shares at Dec. 31, 2018			577
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,842				1,842
Other comprehensive income (loss)	76						76
Common stock issued, stock-based compensation plans	159			159
Common stock issued, stock based compensation plans and other, shares			7
Stock-based compensation expense	217			217
Repurchases of common stock	(2,247)		$ (1)	(390)	(1,856)
Repurchases of common stock, shares			(36)
Dividends declared	(451)				(451)
AOCI, ending balance at Dec. 31, 2019	$ 11,022	$ 1	$ 5	33	11,022	$ 1	(38)
Ending balance, shares at Dec. 31, 2019	548		548
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 1,392				1,392
Other comprehensive income (loss)	148						148
Common stock issued, stock-based compensation plans	142			142
Common stock issued, stock based compensation plans and other, shares			6
Stock-based compensation expense	232			232
Repurchases of common stock	(1,621)			(375)	(1,246)
Repurchases of common stock, shares			(24)
Dividends declared	(480)				(480)
AOCI, ending balance at Dec. 31, 2020	$ 10,836		$ 5	$ 32	$ 10,689		$ 110
Ending balance, shares at Dec. 31, 2020	530		530

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 1,392	$ 1,842	$ 2,101
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	119	39	(65)
Change in unrealized gains and losses on cash flow hedges	29	29	(118)
Change in unrealized losses on available-for-sale investment securities	0	8	0
Other comprehensive income (loss)	148	76	(183)
Comprehensive income	$ 1,540	$ 1,918	$ 1,918

Business Description and Summar

Business Description and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Business Description and Summary of Significant Accounting Policies	The terms “Cognizant,” “we,” “our,” “us” and “the Company” refer to Cognizant Technology Solutions Corporation and its subsidiaries unless the context indicates otherwise. Description of Business. We are one of the world’s leading professional services companies, engineering modern business for the digital era. Our services include digital services and solutions, consulting, application development, systems integration, application testing, application maintenance, infrastructure services and business process services. Digital services have become an increasingly important part of our portfolio, aligning with our clients' focus on becoming data-enabled, customer-centric and differentiated businesses. We are focused on continued investment in four key areas of digital: IoT, AI, experience-driven software engineering and cloud. We tailor our services and solutions to specific industries with an integrated global delivery model that employs client service and delivery teams based at client locations and dedicated global and regional delivery centers. Basis of Presentation, Principles of Consolidation and Use of Estimates. The consolidated financial statements are presented in accordance with GAAP and reflect the consolidated financial position, results of operations, comprehensive income and cash flows of our consolidated subsidiaries for all periods presented. All intercompany balances and transactions have been eliminated in consolidation. The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying disclosures. The COVID-19 pandemic may affect management's estimates and assumptions of variable consideration in contracts with customers as well as other estimates and assumptions, in particular those that require a projection of our financial results, our cash flows or broader economic conditions, such as the annual effective tax rate, the allowance for doubtful accounts, the recoverability of capitalized deferred charges and the fair value of goodwill, long-lived assets and indefinite-lived intangible assets We evaluate our estimates on a continuous basis. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. The actual amounts may vary from the estimates used in the preparation of the accompanying consolidated financial statements. Cash and Cash Equivalents and Investments. Cash and cash equivalents consist of all cash balances, including money market funds, certificates of deposits and commercial paper that have a maturity, at the date of purchase, of 90 days or less. We determine the appropriate classification of our investments in marketable securities at the date of purchase and reevaluate such designation at each balance sheet date. Our held-to-maturity investment securities are financial instruments for which we have the intent and ability to hold to maturity and we classify these securities with maturities less than one year as short-term investments. Any held-to-maturity investment securities with maturities beyond one year from the balance sheet date are classified as noncurrent. Held-to-maturity securities are reported at amortized cost. Interest and amortization of premiums and discounts for debt securities are included in interest income. On initial recognition and on an ongoing basis, we evaluate our held-to-maturity investment securities for expected credit losses collectively when they share similar risk characteristics or individually, when the risk characteristics are different. The allowance for expected credit losses is determined using our historical loss experience. We monitor the credit ratings of the securities in our portfolio to evaluate the need for any changes to the allowance. An increase or a decrease in the allowance for expected credit losses is recorded through income as a credit loss expense or a reversal thereof. The allowance for expected credit losses is presented as a deduction from the amortized cost. A held-to-maturity investment security is written off when deemed uncollectible. Financial Assets and Liabilities. Cash and certain cash equivalents, time deposits, trade receivables, accounts payable and other accrued liabilities are short-term in nature and, accordingly, their carrying values approximate fair value. Property and Equipment. Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is calculated on a straight-line basis over the estimated useful lives of the assets. Leasehold improvements are amortized on a straight-line basis over the shorter of the term of the lease or the estimated useful life of the asset. Deposits paid towards acquisition of long-lived assets and the cost of assets not put in use by the balance sheet date are disclosed under the caption "Capital work-in-progress" in Note 6 . Leases. Our lease asset classes primarily consist of operating leases for office space, data centers and IT equipment. At inception of a contract, we determine whether a contract contains a lease, and if a lease is identified, whether it is an operating or finance lease. In determining whether a contract contains a lease we consider whether (1) we have the right to obtain substantially all of the economic benefits from the use of the asset throughout the term of the contract, (2) we have the right to direct how and for what purpose the asset is used throughout the term of the contract and (3) we have the right to operate the asset throughout the term of the contract without the lessor having the right to change the terms of the contract. Some of our lease agreements contain both lease and non-lease components that we account for as a single lease component for all of our lease asset classes. Our ROU lease assets represent our right to use an underlying asset for the lease term and may include any advance lease payments made and any initial direct costs and exclude lease incentives. Our lease liabilities represent our obligation to make lease payments arising from the terms of the lease. ROU lease assets and lease liabilities are recognized at the commencement of the lease and are calculated using the present value of lease payments over the lease term. Typically, our lease agreements do not provide sufficient detail to arrive at an implicit interest rate. Therefore, we use our estimated country-specific incremental borrowing rate based on information available at the commencement date of the lease to calculate the present value of the lease payments. In estimating our country-specific incremental borrowing rates, we consider market rates of comparable collateralized borrowings for similar terms. Our lease terms may include the option to extend or terminate the lease before the end of the contractual lease term. Our ROU lease assets and lease liabilities include these options when it is reasonably certain that they will be exercised. A portion of our real estate lease costs is subject to annual changes in the CPI. The changes to the CPI are treated as variable lease payments and are recognized in the period in which the obligation for those payments is incurred. Other variable lease costs primarily relate to adjustments for common area maintenance, utilities, property tax and lease concessions due to the COVID-19 pandemic. These variable costs are recognized in the period in which the obligation for those payments is incurred. We elect not to recognize ROU assets and lease liabilities for short-term leases with a term equal to or less than 12 months. We recognize the lease payments in our income statement on a straight-line basis over the lease term and variable lease payments in the period in which the obligation for those payments is incurred. Both ROU assets and finance lease assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the related asset group may not be recoverable. Internal Use Software. We capitalize certain costs that are incurred to purchase, develop and implement internal-use software during the application development phase, which primarily include coding, testing and certain data conversion activities. Capitalized costs are amortized on a straight-line basis over the useful life of the software. Costs incurred in performing planning and post-implementation activities are expensed as incurred. Cloud Computing Arrangements. We capitalize certain implementation costs within prepaid assets that are incurred when implementing cloud computing service or SaaS arrangements, which primarily include efforts associated with configuration and development activities. Once the service is ready for use, capitalized costs are amortized over the term of the arrangement and recognized in income from operations. Software to be Sold, Leased or Marketed. We capitalize costs incurred after technological feasibility is reached but before software is available for general release to clients, which primarily include coding and testing activities. Once the product is ready for general release, capitalized costs are amortized over the useful life of the software. Business Combinations. We account for business combinations using the acquisition method, which requires the identification of the acquirer, the determination of the acquisition date and the allocation of the purchase price paid by the acquirer to the identifiable tangible and intangible assets acquired, the liabilities assumed, including any contingent consideration and any noncontrolling interest in the acquiree at their acquisition date fair values. Goodwill represents the excess of the purchase price over the fair value of net assets acquired, including the amount assigned to identifiable intangible assets. Identifiable intangible assets with finite lives are amortized over their expected useful lives. Acquisition-related costs are expensed in the periods in which the costs are incurred. The results of operations of acquired businesses are included in our consolidated financial statements from the acquisition date . During the fourth quarter of 2019, the Company adjusted the allocation of the purchase price of certain prior period acquisitions that included revenue contracts with the sellers of the acquired businesses. As a result, we recorded a balance sheet adjustment to decrease total assets (primarily impacting intangible assets, goodwill and deferred income taxes) and total liabilities (primarily impacting deferred revenue) by approximately $70 million each. The impact of the adjustment to our operating results was immaterial. Management concluded that the adjustment was not material to any previously issued consolidated financial statements or to the consolidated financial statements as of and for the year ended December 31, 2019. Equity Method Investments. Equity investments that give us the ability to exercise significant influence, but not control, over an investee are accounted for using the equity method of accounting and recorded in the caption "Long-term investments" on our consolidated statements of financial position. Equity method investments are initially recorded at cost. We periodically review the carrying value of our equity method investments to determine if there has been an other-than-temporary decline in the carrying value. The investment balance is increased to reflect contributions and our share of earnings and decreased to reflect our share of losses, distributions, and other-than-temporary impairments. The Company's proportionate share of the net income or loss of the investee is recorded in the caption "Income (loss) from equity method investments" on our consolidated statements of operations. Long-lived Assets and Finite-lived Intangible Assets. We review long-lived assets and certain finite-lived identifiable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. The carrying amount may not be recoverable when the sum of undiscounted expected future cash flows is less than the carrying amount of such asset groups. The impairment loss is determined as the amount by which the carrying amount of the asset group exceeds its fair value. Intangible assets consist primarily of customer relationships and developed technology, which are being amortized on a straight-line basis over their estimated useful lives. Goodwill and Indefinite-lived Intangible Assets. We evaluate goodwill and indefinite-lived intangible assets for impairment at least annually, or as circumstances warrant. Goodwill is evaluated at the reporting unit level by comparing the fair value of the reporting unit with its carrying amount including goodwill. An impairment of goodwill exists if the carrying amount of the reporting unit exceeds its fair value. The impairment loss is the amount by which the carrying amount exceeds the reporting unit’s fair value, limited to the total amount of goodwill allocated to that reporting unit. For indefinite-lived intangible assets, if our annual qualitative assessment indicates that it is more-likely-than-not that an indefinite-lived intangible asset is impaired, we test the assets for impairment by comparing the fair value of such assets to their carrying value. If an impairment is indicated, a write down to the fair value of indefinite-lived intangible asset is recorded. Stock Repurchase Program. Under the Board of Directors authorized stock repurchase program, the Company is authorized to repurchase its Class A common stock through open market purchases, including under a 10b5-1 Plan, or in private transactions, including through ASR agreements entered into with financial institutions, in accordance with applica ble federal securities laws. We account for the repurchased shares as constructively retired. Shares are returned to the status of authorized and unissued shares at the time of repurchase or in the periods they are delivered if repurchased under an ASR. To reflect share repurchases in the consolidated statements of financial position, we (1) reduce common stock for the par value of the shares, (2) reduce additional paid-in capital for the amount in excess of par during the period in which the shares are repurchased and (3) record any residual amount in excess of available additional paid-in capital to retained earnings. Upfront payments related to ASRs are accounted for as a reduction to stockholders’ equity in the consolidated statements of financial position in the period the payments are made. Revenue Recognition. We recognize revenues as we transfer control of deliverables (products, solutions and services) to our clients in an amount reflecting the consideration to which we expect to be entitled. To recognize revenues, we apply the following five step approach: (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 to the performance obligations in the contract, and (5) recognize revenues when a performance obligation is satisfied. We account for a contract when it has approval and commitment from all parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. We apply judgment in determining the customer’s ability and intention to pay based on a variety of factors including the customer’s historical payment experience. For performance obligations where control is transferred over time, revenues are recognized based on the extent of progress towards completion of the performance obligation. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the deliverables to be provided. Revenues related to fixed-price contracts for application development and systems integration services, consulting or other technology services are recognized as the service is performed using the cost to cost method, under which the total value of revenues is recognized on the basis of the percentage that each contract’s total labor cost to date bears to the total expected labor costs. Revenues related to fixed-price application maintenance, testing and business process services are recognized based on our right to invoice for services performed for contracts in which the invoicing is representative of the value being delivered. If our invoicing is not consistent with the value delivered, revenues are recognized as the service is performed based on the cost to cost method described above. The cost to cost method requires estimation of future costs, which is updated as the project progresses to reflect the latest available information; such estimates and changes in estimates involve the use of judgment. The cumulative impact of any revision in estimates is reflected in the financial reporting period in which the change in estimate becomes known and any anticipated losses on contracts are recognized immediately, where appropriate. Revenues related to fixed-price hosting and infrastructure services are recognized based on our right to invoice for services performed for contracts in which the invoicing is representative of the value being delivered. If our invoicing is not consistent with the value delivered, revenues are recognized on a straight-line basis unless revenues are earned and obligations are fulfilled in a different pattern. The revenue recognition method applied to the types of contracts described above provides the most faithful depiction of performance towards satisfaction of our performance obligations; for example, the cost to cost method is used when the value of services provided to the customer is best represented by the costs expended to deliver those services. Revenues related to our time-and-materials, transaction-based or volume-based contracts are recognized over the period the services are provided either using an output method such as labor hours, or a method that is otherwise consistent with the way in which value is delivered to the customer. Revenues related to our non-hosted software license arrangements that do not require significant modification or customization of the underlying software are recognized when the software is delivered as control is transferred at a point in time. For software license arrangements that require significant functionality enhancements or modification of the software, revenues for the software license and related services are recognized as the services are performed in accordance with the methods applicable to application development and systems integration services described above. In software hosting arrangements, the rights provided to the customer, such as ownership of a license, contract termination provisions and the feasibility of the client to operate the software, are considered in determining whether the arrangement includes a license or a service. Sales and usage-based fees promised in exchange for licenses of intellectual property are not recognized as revenue until the uncertainty related to the variable amounts is resolved. Revenues related to software maintenance and support are generally recognized on a straight-line basis over the contract period. Incentive revenues, volume discounts, or any other form of variable consideration is estimated using either the sum of probability weighted amounts in a range of possible consideration amounts (expected value) or the single most likely amount in a range of possible consideration amounts (most likely amount), depending on which method better predicts the amount of consideration to which we may be entitled. We include in the transaction price variable consideration only to the extent it is probable that a significant reversal of revenues recognized will not occur when the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether and when to include estimated amounts in the transaction price may involve judgment and are based largely on an assessment of our anticipated performance and all information that is reasonably available to us. Revenues also include the reimbursement of out-of-pocket expenses. Our warranties generally provide a customer with assurance that the related deliverable will function as the parties intended because it complies with agreed-upon specifications and is therefore not considered an additional performance obligation in the contract. We may enter into arrangements that consist of multiple performance obligations. Such arrangements may include any combination of our deliverables. To the extent a contract includes multiple promised deliverables, we apply judgment to determine whether promised deliverables are capable of being distinct and are distinct in the context of the contract. If these criteria are not met, the promised deliverables are accounted for as a combined performance obligation. For arrangements with multiple distinct performance obligations, we allocate consideration among the performance obligations based on their relative standalone selling price. Standalone selling price is the price at which we would sell a promised good or service separately to the customer. When not directly observable, we typically estimate standalone selling price by using the expected cost plus a margin approach. We typically establish a standalone selling price range for our deliverables, which is reassessed on a periodic basis or when facts and circumstances change. We assess the timing of the transfer of goods or services to the customer as compared to the timing of payments to determine whether a significant financing component exists. As a practical expedient, we do not assess the existence of a significant financing component when the difference between payment and transfer of deliverables is a year or less. If the difference in timing arises for reasons other than the provision of finance to either the customer or us, no financing component is deemed to exist. The primary purpose of our invoicing terms is to provide customers with simplified and predictable ways of purchasing our services, not to receive or provide financing from or to customers. We do not consider set up or transition fees paid upfront by our customers to represent a financing component, as such fees are required to encourage customer commitment to the project and protect us from early termination of the contract. Our contracts may be modified to add, remove or change existing performance obligations. The accounting for modifications to our contracts involves assessing whether the services added to an existing contract are distinct and whether the pricing is at the standalone selling price. Services added that are not distinct are accounted for on a cumulative catch up basis, while those that are distinct are accounted for prospectively, either as a separate contract if the additional services are priced at the standalone selling price, or as a termination of the existing contract and creation of a new contract if not priced at the standalone selling price. Services added to our application development and systems integration service contracts are typically not distinct, while services added to our other contracts, including application maintenance, testing and business process services contracts, are typically distinct. From time to time, we may enter into arrangements with third party suppliers to resell products or services. In such cases, we evaluate whether we are the principal (i.e., report revenues on a gross basis) or agent (i.e., report revenues on a net basis). In doing so, we first evaluate whether we control the good or service before it is transferred to the customer. If we control the good or service before it is transferred to the customer, we are the principal; if not, we are the agent. Determining whether we control the good or service before it is transferred to the customer may require judgment. Trade Accounts Receivable, Contract Assets and Contract Liabilities. We classify our right to consideration in exchange for deliverables as either a receivable or a contract asset. A receivable is a right to consideration that is unconditional (i.e., only the passage of time is required before payment is due). For example, we recognize a receivable for revenues related to our time and materials and transaction or volume-based contracts when earned regardless of whether amounts have been billed. We present such receivables in "Trade accounts receivable, net" in our consolidated statements of financial position at their net estimated realizable value. A contract asset is a right to consideration that is conditional upon factors other than the passage of time. Contract assets are presented in "Other current assets" in our consolidated statements of financial position and primarily relate to unbilled amounts on fixed-price contracts utilizing the cost to cost method of revenue recognition. Our contract liabilities, or deferred revenue, consist of advance payments from clients and billings in excess of revenues recognized. We classify deferred revenue as current or noncurrent based on the timing of when we expect to recognize the revenues. Our contract assets and contract liabilities are reported on a net basis by contract at the end of each reporting period. The difference between the opening and closing balances of our contract assets and contract liabilities primarily results from the timing difference between our performance obligations and the client’s payment. We receive payments from clients based on the terms established in our contracts, which vary by contract type. Allowance for Expected Credit Losses . We calculate expected credit losses for our trade accounts receivable and contract assets. Expected credit losses include losses expected based on known credit issues with specific customers as well as a general expected credit loss allowance based on relevant information about past events, including historical loss rates, current conditions, and reasonable economic forecasts that affect collectibility. We update our allowance for expected credit losses on a quarterly basis with changes in the allowance recognized in income from operations. Costs to Fulfill. Recurring operating costs for contracts with customers are recognized as incurred. Certain eligible, nonrecurring costs (i.e., set-up or transition costs) are capitalized when such costs (1) relate directly to the contract, (2) generate or enhance resources of the Company that will be used in satisfying the performance obligation in the future, and (3) are expected to be recovered. These costs are expensed ratably over the estimated life of the customer relationship, including expected contract renewals. In determining the estimated life of the customer relationship, we evaluate the average contract term, on a portfolio basis by nature of the services to be provided, and apply judgment in evaluating the rate of technological and industry change. Capitalized amounts are monitored regularly for impairment. Impairment losses are recorded when projected remaining undiscounted operating cash flows are not sufficient to recover the carrying amount of the capitalized costs to fulfill. Stock-Based Compensation. Stock-based compensation expense for awards of equity instruments to employees and non-employee directors is determined based on the grant date fair value of those awards. We recognize these compensation costs net of an estimated forfeiture rate over the requisite service period of the award. Forfeitures are estimated on the date of grant and revised if actual or expected forfeiture activity differs materially from original estimates. Stock-based compensation costs for PSUs that vest proportionally are recognized on a graded-vesting basis over the vesting period based on the most probable outcome of the performance conditions. If the minimum performance targets are not met, no compensation cost is recognized and any recognized compensation cost is reversed except for awards subject to a market condition. The fair value of RSUs and PSUs is determined based on the number of stock units granted and the quoted price of our stock at the date of grant. The fair value of PSUs granted subject to a market condition is determined using a Monte Carlo valuation model. Foreign Currency. The assets and liabilities of our foreign subsidiaries whose functional currency is not the U.S. dollar are translated into U.S. dollars at current exchange rates while revenues and expenses are translated at average monthly exchange rates. The resulting translation adjustments are recorded in the caption "Accumulated other comprehensive income (loss)" on the consolidated statements of financial position. Foreign currency transactions and balances are those that are denominated in a currency other than the entity’s functional currency. An entity's functional currency is the currency of the primary economic environment in which it operates. The U.S. dollar is the functional currency for some of our foreign subsidiaries. For these subsidiaries, transactions and balances denominated in the local currency are foreign currency transactions. Foreign currency transactions and balances related to non-monetary assets and liabilities are remeasured to the functional currency of the entity at historical exchange rates while monetary assets and liabilities are remeasured to the functional currency of the entity at current exchange rates. Foreign currency exchange gains or losses from remeasurement are included in the caption "Foreign currency exchange gain (losses), net" on our consolidated statements of operations together with gains or losses on our undesignated foreign currency hedges. Derivative Financial Instruments. Derivative financial instruments are recorded on our consolidated statements of financial position as either an asset or liability measured at its fair value as of the reporting date. Our derivative financial instruments consist primarily of foreign exchange forward and option contracts. For derivative financial instruments to qualify for hedge accounting, the following criteria must be met: (1) the hedging instrument must be designated as a hedge; (2) the hedged exposure must be specifically identifiable and must expose us to risk; and (3) it must be expected that a change in fair value of the hedging instrument and an opposite change in the fair value of the hedged exposure will have a high degree of correlation. Changes in our derivatives’ fair values are recognized in net income unless specific hedge accounting and documentation criteria are met (i.e., the instruments are designated and accounted for as hedges). We record the effective portion of the unrealized gains and losses on our derivative financial instruments that are designated as cash flow hedges in the caption "Accumulated other comprehensive income (loss)" in the consolidated statements of financial position. Any ineffectiveness or excluded portion of a designated cash flow hedge is recognized in net income. Upon occurrence of the hedged transaction, the gains and losses on the derivative are recognized in net income. Income Taxes. We provide for income taxes utilizing the asset and liability method of accounting. Under this method, deferred income taxes are recorded to reflect the tax consequences in future years of differences between the tax basis of assets and liabilities and their financial reporting amounts at each balance sheet date, based on enacted tax laws and statutory tax rates applicable to the periods in which the differences are expected to affect taxable income. If it is determined that it is more likely than not that future tax benefits associated with a deferred income tax asset will not be realized, a valuation allowance is provided. The effect of a change in tax rates on deferred income tax assets and liabilities is recognized in the provision for income taxes in the period that includes the enactment date. Our provision for income taxes also includes the impact of provisions established for uncertain income tax positions, as well as any related penalties and interest. We adjust these reserves in light of changing facts and circumstances, such as the closing of a tax audit. To the extent that the final outcome of these matters differs from the amounts recorded, such differences will impact the provision for income taxes in the period i

Revenues (Notes)

Revenues (Notes)	12 Months Ended
	Dec. 31, 2020
Revenues [Abstract]
Revenue from Contract with Customer [Text Block]	Disaggregation of Revenues The tables below present disaggregated revenues from contracts with clients by client location, service line and contract-type for each of our business segments. We believe this disaggregation best depicts how the nature, amount, timing and uncertainty of our revenues and cash flows are affected by industry, market and other economic factors. Our consulting and technology services include consulting, application development, systems integration, and application testing services as well as software solutions and related services while our outsourcing services include application maintenance, infrastructure and business process services. Revenues are attributed to geographic regions based upon client location. Substantially all of the revenue in our North America region relates to operations in the United States. Year Ended December 31, 2020 Financial Services Healthcare Products and Resources Communications, Media and Technology Total (in millions) Revenues Geography: North America $ 4,013 $ 4,181 $ 2,650 $ 1,737 $ 12,581 United Kingdom 463 157 371 344 1,335 Continental Europe 629 434 413 177 1,653 Europe - Total 1,092 591 784 521 2,988 Rest of World 516 80 262 225 1,083 Total $ 5,621 $ 4,852 $ 3,696 $ 2,483 $ 16,652 Service line: Consulting and technology services $ 3,691 $ 2,786 $ 2,249 $ 1,456 $ 10,182 Outsourcing services 1,930 2,066 1,447 1,027 6,470 Total $ 5,621 $ 4,852 $ 3,696 $ 2,483 $ 16,652 Type of contract: Time and materials $ 3,548 $ 1,950 $ 1,548 $ 1,515 $ 8,561 Fixed-price 1,736 1,777 1,741 871 6,125 Transaction or volume-based 337 1,125 407 97 1,966 Total $ 5,621 $ 4,852 $ 3,696 $ 2,483 $ 16,652 Year Ended December 31, 2019 Financial Services Healthcare Products and Resources Communications, Media and Technology Total (in millions) Revenues Geography: North America $ 4,137 $ 4,147 $ 2,678 $ 1,764 $ 12,726 United Kingdom 484 130 380 319 1,313 Continental Europe 728 341 453 169 1,691 Europe - Total 1,212 471 833 488 3,004 Rest of World 520 77 259 197 1,053 Total $ 5,869 $ 4,695 $ 3,770 $ 2,449 $ 16,783 Service line: Consulting and technology services $ 3,782 $ 2,564 $ 2,295 $ 1,305 $ 9,946 Outsourcing services 2,087 2,131 1,475 1,144 6,837 Total $ 5,869 $ 4,695 $ 3,770 $ 2,449 $ 16,783 Type of contract: Time and materials $ 3,651 $ 1,845 $ 1,632 $ 1,528 $ 8,656 Fixed-price 1,922 1,635 1,730 803 6,090 Transaction or volume-based 296 1,215 408 118 2,037 Total $ 5,869 $ 4,695 $ 3,770 $ 2,449 $ 16,783 Year Ended December 31, 2018 Financial Services Healthcare Products and Resources Communications, Media and Technology Total (in millions) Revenues Geography: North America $ 4,162 $ 4,254 $ 2,397 $ 1,480 $ 12,293 United Kingdom 481 91 358 344 1,274 Continental Europe 666 270 440 187 1,563 Europe - Total 1,147 361 798 531 2,837 Rest of World 536 53 220 186 995 Total $ 5,845 $ 4,668 $ 3,415 $ 2,197 $ 16,125 Service line: Consulting and technology services $ 3,571 $ 2,553 $ 2,024 $ 1,161 $ 9,309 Outsourcing services 2,274 2,115 1,391 1,036 6,816 Total $ 5,845 $ 4,668 $ 3,415 $ 2,197 $ 16,125 Type of contract: Time and materials $ 3,762 $ 1,836 $ 1,506 $ 1,366 $ 8,470 Fixed-price 1,859 1,852 1,521 734 5,966 Transaction or volume-based 224 980 388 97 1,689 Total $ 5,845 $ 4,668 $ 3,415 $ 2,197 $ 16,125 In the fourth quarter of 2020, we made an offer to settle and exit a large customer engagement in Financial Services in Continental Europe. The offer includes, among other terms, a proposed payment and the forgiveness of certain receivables. The 2020 impact of the Proposed Exit was a reduction of revenues of $118 million and additional expenses of $33 million, primarily related to the impairment of long-lived assets. While the amounts recorded are based on our best estimate of the expected terms of the exit, the negotiations are ongoing and, as such, we may not reach an agreement or the final terms of the agreement that is reached may materially differ from those contemplated in our accounting. In either instance, there could be additional impacts to our statement of operations, financial condition and our cash flows. Costs to Fulfill The following table presents information related to the capitalized costs to fulfill, such as setup or transition activities . Costs to fulfill are recorded in "Other noncurrent assets" in our consolidated statements of financial position and the amortization expense of costs to fulfill is included in "Cost of revenues" in our consolidated statement of operations. Costs to obtain contracts were immaterial for the period disclosed. 2020 2019 (in millions) Beginning balance $ 485 $ 400 Costs capitalized 98 189 Amortization expense (102) (79) Impairment charge (14) (25) Ending balance $ 467 $ 485 Contract Balances A contract asset is a right to consideration that is conditional upon factors other than the passage of time. Contract assets are presented in "Other current assets" in our consolidated statements of financial position and primarily relate to unbilled amounts on fixed-price contracts utilizing the cost to cost method of revenue recognition. The table below shows significant movements in contract assets: 2020 2019 (in millions) Beginning balance $ 334 $ 305 Revenues recognized during the period but not billed 289 313 Amounts reclassified to trade accounts receivable (308) (284) Ending balance $ 315 $ 334 Our contract liabilities, or deferred revenue, consist of advance payments and billings in excess of revenues recognized. The table below shows significant movements in the deferred revenue balances (current and noncurrent): 2020 2019 (in millions) Beginning balance $ 336 $ 348 Amounts billed but not recognized as revenues 368 319 Revenues recognized related to the opening balance of deferred revenue (285) (261) Other (1) — (70) Ending balance $ 419 $ 336 (1) See the Business Combinations section in Note 1 . Revenues recognized during the year ended December 31, 2020 for performance obligations satisfied or partially satisfied in previous periods were immaterial. Remaining Performance Obligations As of December 31, 2020, the aggregate amount of transaction price allocated to remaining performance obligations, was $1,446 million , of which approximately 75% is expected to be recognized as revenues within 2 years. Disclosure is not required for performance obligations that meet any of the following criteria: (1) contracts with a duration of one year or less as determined under th e New Revenue Standard, (2) contracts for which we recognize revenues based on the right to invoice for services performed, (3) variable consideration allocated entirely to a wholly unsatisfied performance obligation or to a wholly unsatisfied promise to transfer a distinct good or service that forms part of a single performance obligation in accordance with ASC 606-10-25-14(b), for which the criteria in ASC 606-10-32-40 have been met, or (4) variable consideration in the form of a sales-based or usage based royalty promised in exchange for a license of intellectual property. Many of our performance obligations meet one or more of these exemptions and therefore are not included in the remaining performance obligation amount disclosed above. Trade Accounts Receivable and Allowance for Doubtful Accounts We calculate expected credit losses for our trade accounts receivable based on historical credit loss rates for each aging category as adjusted for the current market conditions and forecasts about future economic conditions. The following table presents the activity in the allowance for our trade accounts receivable: 2020 2019 (in millions) Beginning balance $ 67 $ 78 Impact of adoption of the Credit Loss Standard (1) — Provision for expected credit losses 8 (11) Write-offs charged against the allowance (17) — Ending balance $ 57 $ 67

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Business Combinations	Acquisitions completed during each of the three years ended December 31, 2020, 2019 and 2018 were not individually or in the aggregate material to our operations. Accordingly, pro forma results have not been presented. We have allocated the purchase price related to these transactions to tangible and intangible assets and liabilities, including deductible and non-deductible goodwill, based on their estimated fair values. The primary items that generated goodwill are the value of the acquired assembled workforces and synergies between the acquired companies and us, neither of which qualify as an amortizable intangible asset. 2020 In 2020, we acquired 100% ownership of: • Code Zero, a provider of consulting and implementation services acquired to strengthen our cloud solutions portfolio and Salesforce Configure-Price-Quote and billing capabilities (acquired on January 31, 2020); • Lev, a Salesforce Platinum Partner specializing in digital marketing consultancy and implementation of custom cloud solutions acquired to further expand our global Salesforce practice (acquired on March 27, 2020); • EI-Technologies, a digital technology consulting firm and leading Salesforce specialist acquired to expand our global Salesforce practice (acquired on May 29, 2020); • Collaborative Solutions, a provider of Workday enterprise cloud applications for finance and human resources acquired to strengthen our portfolio of cloud offerings (acquired on June 10, 2020); • New Signature, an independent Microsoft public cloud transformation company acquired to expand our hyperscale cloud advisory services and provide the foundation for our new, dedicated practice centered on Microsoft cloud solutions (acquired on August 18, 2020); • the net assets of Tin Roof, a custom software and digital product development services company acquired to expand our software product engineering footprint in the United States (acquired on September 16, 2020); • 10 th Magnitude, a leading cloud specialist focused on the Microsoft Azure cloud computing platform acquired to expand our Microsoft Azure expertise (acquired on September 30, 2020); • the net assets of Bright Wolf, a technology service provider specializing in customer Industrial IoT solutions acquired to expand our smart products offering and expertise in architecting and implementing Industrial IoT solutions (acquired on November 2, 2020); and • Inawisdom, an Amazon Web Services consulting partner with expertise in AI, machine learning, and data analytics acquired to expand our client services in Europe and strengthen our end-to-end cloud-native AI and machine learning solutions portfolio (acquired on December 18, 2020). The allocations of preliminary purchase price to the fair value of the aggregate assets acquired and liabilities assumed were as follows: Collaborative Solutions New Signature Tin Roof 10th Magnitude Others Total Weighted Average Useful Life (dollars in millions) Cash $ 10 $ 13 $ — $ 2 $ 10 $ 35 Trade accounts receivable 38 13 10 7 21 89 Property and equipment and other assets 6 6 1 2 15 30 Operating lease assets, net 6 7 2 4 13 32 Non-deductible goodwill 44 292 — 90 66 492 Deductible goodwill 281 — 86 39 92 498 Customer relationship intangible assets 37 8 69 10 21 145 9.8 years Other intangible assets 8 1 — — 2 11 5.4 years Current liabilities (25) (20) (13) (15) (23) (96) Noncurrent liabilities (5) (8) (2) (5) (15) (35) Purchase price, inclusive of contingent consideration (1) $ 400 $ 312 $ 153 $ 134 $ 202 $ 1,201 (1) The purchase price for our acquisitions includes contingent consideration components with a collective maximum payout of $59 million, valued at $42 million at the date of acquisition, which is contingent upon achieving certain performance thresholds during the first two calendar years following the date of acquisition. For the year ended December 31, 2020, revenues from acquisitions completed in 2020, since the dates of acquisition, were $222 million. For acquisitions completed in 2020, the allocation is preliminary and will be finalized as soon as practicable within the measurement period, but in no event later than one year following the date of acquisition. 2019 In 2019, we acquired 100% ownership of: • Mustache, a creative content agency based in the United States, acquired to extend our capabilities in creating original and branded content for digital, broadcast and social mediums (acquired on January 15, 2019); • Meritsoft, a financial software company based in Ireland, acquired to complement our service offerings to capital markets institutions (acquired on March 4, 2019); • Samlink, a developer of services and solutions for the financial sector based in Finland, acquired to strengthen our banking capabilities and create a strategic partnership with three Finnish financial institutions to transform and operate a shared core banking platform (acquired on April 1, 2019); • Zenith, a life sciences company based in Ireland, acquired to extend our service capabilities for connected biopharmaceutical and medical device manufacturers (acquired on July 29, 2019); and • Contino, a technology consulting firm acquired to extend our capabilities in enterprise DevOps and cloud transformation (acquired on October 31, 2019). The allocations of purchase price to the fair value of the aggregate assets acquired and liabilities assumed were as follows: Contino Meritsoft Zenith Others Total Weighted Average Useful Life (dollars in millions) Cash $ 7 $ 14 $ 9 $ 15 $ 45 Current assets 16 6 52 21 95 Property and equipment and other noncurrent assets 4 1 6 14 25 Non-deductible goodwill 198 147 76 21 442 Customer relationship intangible assets 29 46 73 19 167 10.7 years Other intangible assets 2 29 4 6 41 6.1 years Current liabilities (11) (3) (35) (22) (71) Noncurrent liabilities (10) (12) (17) (10) (49) Purchase price, inclusive of contingent consideration $ 235 $ 228 $ 168 $ 64 $ 695

Restructuring Charges

Restructuring Charges	12 Months Ended
	Dec. 31, 2020
Restructuring Charges [Abstract]
Realignment Charges	During 2020, we incurred costs related to both our realignment program and our 2020 Fit for Growth Plan. Our realignment program, which began in 2017, improved our client focus, our cost structure and the efficiency and effectiveness of our delivery while continuing to drive revenue growth. Our 2020 Fit for Growth Plan, which began in the fourth quarter of 2019, simplified our organizational model and optimized our cost structure in order to partially fund the investments required to execute on our strategy and advance our growth agenda and included our decision to exit certain content-related services that were not in line with our strategic vision for the Company. The total costs related to our realignment program and our 2020 Fit for Growth Plan are reported in "Restructuring charges" in our consolidated statements of operations. We do not allocate these charges to individual segments in internal management reports used by the chief operating decision maker. Accordingly, such expenses are included in our segment reporting as “unallocated costs”. See Note 19 . Charges related to our realignment program and our 2020 Fit for Growth Plan were as follows: Years Ended December 31, 2020 2019 2018 (in millions) Realignment Program: Employee separation costs $ — $ 64 $ 18 Executive Transition Costs — 22 — Employee retention costs 15 45 — Professional fees 27 38 1 2020 Fit for Growth Plan: Employee separation costs 127 45 — Employee retention costs 5 2 — Facility exit costs and other charges (1) 41 1 — Total restructuring charges $ 215 $ 217 $ 19 (1) Includes $7 million of accelerated depreciation for the year ended December 31, 2020. The 2020 Fit for Growth Plan charges include $23 million and $5 million of costs incurred in 2020 and 2019, respectively, related to our exit from certain content-related services. Changes in our accrued employee separation costs, for both our realignment program and our 2020 Fit for Growth Plan, included in "Accrued expenses and other current liabilities" in our consolidated statements of financial position, are presented in the table below. 2020 2019 (in millions) Beginning balance $ 47 $ — Employee separation costs accrued 127 109 Payments made 157 62 Ending balance $ 17 $ 47

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Investments	Our investments were as follows as of December 31: 2020 2019 (in millions) Short-term investments: Equity investment security $ 27 $ 26 Held-to-maturity investment securities 14 287 Time deposits (1) 3 466 Total short-term investments $ 44 $ 779 Long-term investments: Equity and cost method investments $ 35 $ 17 Time deposits (1) 405 — Total long-term investments $ 440 $ 17 (1) As of December 31, 2020 , $405 million in restricted time deposits related to deposits under lien with the ITD were classified as long-term. As of December 31, 2019, $414 million in restricted time deposits were classified as short-term. See Note 11 . Equity Investment Security Our equity investment security is a U.S. dollar denominated investment in a fixed income mutual fund. Realized and unrealized gains and losses were immaterial for the years ended December 31, 2020 and 2019. Available-for-Sale Investment Securities During 2019, all of our available-for-sale investment securities either matured or were sold. We determine the cost of the securities sold based on the specific identification method. Proceeds from sales of available-for-sale investment securities and the gross gains and losses that have been included in earnings as a result of those sales were as follows: 2020 2019 2018 (in millions) Proceeds from sales of available-for-sale investment securities $ — $ 1,712 $ 1,285 Gross gains $ — $ 6 $ — Gross losses — (5) (4) Net realized gains (losses) on sales of available-for-sale investment securities $ — $ 1 $ (4) Held-to-Maturity Investment Securities Our held-to-maturity investment securities consist of Indian rupee denominated investments primarily in commercial paper and international corporate bonds. Our investment guidelines are to purchase securities that are investment grade at the time of acquisition. The basis for the measurement of fair value of our held-to-maturity investments is Level 2 in the fair value hierarchy. The amortized cost and fair value of held-to-maturity investment securities were as follows as of December 31: 2020 2019 Amortized Fair Amortized Fair (in millions) Short-term investments, due within one year: Corporate and other debt securities $ 14 $ 14 $ 101 $ 101 Commercial paper — — 186 186 Total short-term held-to-maturity investments $ 14 $ 14 $ 287 $ 287 As of December 31, 2020, there were no held-to-maturity investment securities in an unrealized loss position. As of December 31, 2019, $70 million in commercial paper and $42 million in corporate and other debt securities were in an unrealized loss position, the total unrealized loss was less than $1 million and none of the securities had been in an unrealized loss position for longer than 12 months. The sec urities in our portfolio are highly rated and short-term in nature. As of December 31, 2020, our corporate and other debt securities were rated AAA by CRISIL, an Indian subsidiary of S&P Global. Equity and Cost Method Investments As of December 31, 2020 and 2019, we had equity method investments of $31 million and $9 million, respectively. During 2020, we acquired a $26 million equity method investment in the technology sector. In addition, we have an equity method investment which consists of a 49% ownership interest in a strategic consulting firm specializing in the use of human sciences to help business leaders better understand customer behavior. During 2019, as a result of events indicating one of our investments experienced an other-than-temporary impairment, we assessed its fair value and determined that the carrying value exceeded the fair value. As such, we recorded an impairment charge of $57 million in the fourth quarter of 2019 within the caption "Income (loss) from equity method investments" in our consolidated statement of operations. In determining the fair value of the equity method investment we considered results from the following valuation methodologies: income approach, based on discounted future cash flows, market approach, based on current market multiples and net asset value approach, based on the assets and liabilities of the investee. The basis for the measurement of fair value for this equity method investment is Level 3 in the fair value hierarchy.

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment, Net [Abstract]
Property and Equipment, net	Property and equipment were as follows as of December 31: Estimated Useful Life 2020 2019 (in years) (in millions) Buildings 30 $ 783 $ 790 Computer equipment 3 – 5 636 516 Computer software 3 – 8 840 820 Furniture and equipment 5 – 9 761 702 Land 7 11 Capital work-in-progress 122 133 Leasehold improvements Shorter of the lease term or 424 379 Sub-total 3,573 3,351 Accumulated depreciation and amortization (2,322) (2,042) Property and equipment, net $ 1,251 $ 1,309 Depreciation and amortization expense related to property and equipment was $407 million, $363 million and $347 million for the years ended December 31, 2020, 2019 and 2018, respectively. The gross amount of property and equipment recorded under finance leases was $37 million and $30 million as of December 31, 2020 and 2019, respectively. Accumulated amortization for our ROU finance lease assets was $23 million and $14 million as of December 31, 2020 and 2019, respectively. Amortization expense related to our ROU finance lease assets was $7 million and $11 million for the year ended December 31, 2020 and 2019, respectively. Amortization expense related to our capital lease assets was immaterial for the year ended December 31, 2018. The gross amount of property and equipment recorded for software to be sold, leased or marketed reported in the caption "Computer software" above was $159 million and $129 million as of December 31, 2020 and 2019, respectively. Accumulated amortization for software to be sold, leased or marketed was $73 million and $46 million as of December 31, 2020 and 2019, respectively. Amortization expense for software to be sold, leased or marketed recorded as property and equipment was $30 million, $22 million and $14 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Leases (Notes)

Leases (Notes)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Lessee, Operating Leases [Text Block]	The following table provides information on the components of our operating and finance leases included in our consolidated statement of financial position as of December 31: Leases Location on Statement of Financial Position 2020 2019 Assets (in millions) ROU operating lease assets Operating lease assets, net $ 1,013 $ 926 ROU finance lease assets Property and equipment, net 14 16 Total $ 1,027 942 Liabilities Current Operating lease Operating lease liabilities $ 211 202 Finance lease Accrued expenses and other current liabilities 11 11 Noncurrent Operating lease Operating lease liabilities, noncurrent 846 745 Finance lease Other noncurrent liabilities 11 15 Total $ 1,079 $ 973 For the years ended December 31, 2020 and 2019, our operating lease costs were $302 million and $264 million, respectively, including variable lease costs of $14 million and $18 million, respectively. Our short-term lease rental expense was $20 million and $16 million for the years ended December 31, 2020 and 2019, respectively. Lease interest expense related to our finance leases for years ended December 31, 2020 and 2019 was immaterial. The following table provides information on the weighted average remaining lease term and weighted average discount rate for our operating leases as of December 31: Operating Lease Term and Discount Rate 2020 2019 Weighted average remaining lease term 6.2 years 6.0 years Weighted average discount rate 5.7 % 6.0 % The following table provides supplemental cash flow information related to our operating leases as of December 31: 2020 2019 (in millions) Cash paid for amounts included in the measurement of operating lease liabilities $ 271 $ 232 ROU assets obtained in exchange for operating lease liabilities 273 274 Cash paid for amounts included in the measurement of finance lease liabilities and ROU assets obtained in exchange for finance lease liabilities were each immaterial for the years ended December 31, 2020 and 2019. The following table provides the schedule of maturities of our operating lease liabilities and a reconciliation of the undiscounted cash flows to the operating lease liabilities recognized in the statement of financial position as of December 31: 2020 (in millions) 2021 $ 260 2022 218 2023 180 2024 143 2025 121 Thereafter 349 Total lease payments 1,271 Interest (214) Total lease liabilities $ 1,057 As of December 31, 2020, we had $92 million of additional obligations related to operating leases whose lease term had yet to commence and which are therefore not included in our statement of financial position. These leases are primarily related to real estate and will commence in various months in 2021 and 2022 with lease terms of 1 year to 11 years.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, net	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, net	Changes in goodwill by our reportable segments were as follows for the years ended December 31, 2020 and 2019: Segment January 1, 2020 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments December 31, 2020 (in millions) Financial Services $ 700 $ 204 $ 28 $ 932 Healthcare 2,595 149 11 2,755 Products and Resources 417 346 17 780 Communications, Media and Technology 267 289 8 564 Total goodwill $ 3,979 $ 988 $ 64 $ 5,031 Segment January 1, 2019 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments Other (1) December 31, 2019 (in millions) Financial Services $ 411 $ 288 $ (2) $ 3 $ 700 Healthcare 2,469 86 — 40 2,595 Products and Resources 384 18 1 14 417 Communications, Media and Technology 217 49 1 — 267 Total goodwill $ 3,481 $ 441 $ — $ 57 $ 3,979 (1) See the Business Combinations section in Note 1 . Beginning with the first quarter of 2020, COVID-19 negatively affected all major economic and financial markets and, although there is a wide range of possible outcomes and the associated impact is highly dependent on variables that are difficult to forecast, we deemed the deterioration in general economic conditions sufficient to trigger an interim impairment testing of goodwill as of March 31, 2020. Our interim test results as of March 31, 2020 indicated that the fair values of all of our reporting units exceeded their carrying values and thus, no impairment of goodwill existed as of March 31, 2020. Based on our most recent goodwill impairment assessment performed as of October 31, 2020, we concluded that the goodwill in each of our reporting units was not at risk of impairment. We have not recognized any impairment losses on our goodwill. Components of intangible assets were as follows as of December 31: 2020 2019 Gross Carrying Accumulated Net Carrying Gross Carrying Accumulated Net Carrying (in millions) Customer relationships $ 1,333 $ (490) $ 843 $ 1,181 $ (390) $ 791 Developed technology 388 (286) 102 388 (239) 149 Indefinite lived trademarks 72 — 72 72 — 72 Finite lived trademarks and other 80 (51) 29 71 (42) 29 Total intangible assets $ 1,873 $ (827) $ 1,046 $ 1,712 $ (671) $ 1,041 Other than certain trademarks with indefinite lives, our intangible assets have finite lives and, as such, are subject to amortization. Amortization of intangible assets totaled $152 million for 2020, $162 million for 2019 and $151 million for 2018. The following table provides the estimated amortization expense related to our existing intangible assets for the next five years. Estimated Amortization (in millions) 2021 $ 159 2022 150 2023 107 2024 102 2025 99

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2020
Accrued Expenses And Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities were as follows as of December 31: 2020 2019 (in millions) Compensation and benefits $ 1,607 $ 1,239 Customer volume and other incentives 266 251 Derivative financial instruments 1 8 Income taxes 34 152 Professional fees 143 137 Travel and entertainment 7 24 Other 461 380 Total accrued expenses and other current liabilities $ 2,519 $ 2,191

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	In 2018, we entered into a Credit Agreement providing for a $750 million Term Loan and a $1,750 million uns ecured revolving credit facility, which are due to mature in November 2023. We are required under the Credit Agreement to make scheduled quarterly principal payments on the Term Loan. The Credit Agreement requires interest to be paid, at our option, at either the ABR or the Eurocurrency Rate (each as defined in the Credit Agreement), plus, in each case, an Applicable Margin (as defined in the Credit Agreement). Initially, the Applicable Margin is 0.875% with respect to Eurocurrency Rate loans and 0.00% with respect to ABR loans. Subsequently, the Applicable Margin with respect to Eurocurrency Rate loans may range from 0.75% to 1.125%, depending on our public debt ratings (or, if we have not received public debt ratings, from 0.875% to 1.125%, depending on our Leverage Ratio, which is the ratio of indebtedness for borrowed money to Consolidated EBITDA, as defined in the Credit Agreement). Our Credit Agreement also provides a mechanism for determining an alternative rate of interest to the Eurocurrency rate after LIBOR is no longer available. Under the Credit Agreement, we are required to pay commitment fees on the unused portion of the revolving credit facility, which vary based on our public debt ratings (or, if we have not received public debt ratings, on the Leverage Ratio). As the interest rates on our Term Loan and any notes outstanding under the revolving credit facility are variable, the fair value of our debt balances approximates their carrying value as of December 31, 2020 and 2019. The Credit Agreement contains customary affirmative and negative covenants as well as a financial covenant. The financial covenant is tested at the end of each fiscal quarter and requires us to maintain a Leverage Ratio, which is the ratio of indebtedness for borrowed money to Consolidated EBITDA, as defined in the Credit Agreement, not in excess of 3.50 to 1.00, or for a period of up to four quarters following certain material acquisitions, 3.75 to 1.00. We were in compliance with all debt covenants and representations of the Credit Agreement as of December 31, 2020. In February 2020, our India subsidiary renewed its 13 billion Indian rupee ($178 million at the December 31, 2020 exchange rate) working capital facility, which requires us to repay any balances within 90 days from the date of disbursement. There is a 1.0% prepayment penalty applicable to payments made within 30 days of disbursement. This working capital facility contains affirmative and negative covenants and may be renewed annually in February. As of December 31, 2020, we have not borrowed funds under this facility. Short-term Debt The following summarizes our short-term debt balances as of December 31: 2020 2019 Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate (in millions) (in millions) Term Loan - current maturities $ 38 1.0 % $ 38 2.6 % Long-term Debt The following summarizes our long-term debt balances as of December 31: 2020 2019 (in millions) Term Loan $ 703 $ 741 Less: Current maturities (38) (38) Deferred financing costs (2) (3) Long-term debt, net of current maturities $ 663 $ 700 The following represents the schedule of maturities of our term loan: Year Amounts (in millions) 2021 $ 38 2022 38 2023 627 $ 703

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income before provision for income taxes shown below is based on the geographic location to which such income was attributed for years ended December 31: 2020 2019 2018 (in millions) United States $ 814 $ 931 $ 947 Foreign 1,282 1,612 1,850 Income before provision for income taxes $ 2,096 $ 2,543 $ 2,797 The provision for income taxes consisted of the following components for the years ended December 31: 2020 2019 2018 (in millions) Current: Federal and state $ 137 $ 549 $ 241 Foreign 383 400 449 Total current provision 520 949 690 Deferred: Federal and state (77) (320) 1 Foreign 261 14 7 Total deferred provision (benefit) 184 (306) 8 Total provision for income taxes $ 704 $ 643 $ 698 In March 2020, the Indian parliament enacted the Budget of India, which contained a number of provisions related to income tax, including a replacement of the DDT, previously due from the dividend payer, with a tax payable by the shareholder receiving the dividend. This provision reduced the tax rate applicable to us for cash repatriated from India. Following this change, during the first quarter of 2020, we limited our indefinite reinvestment assertion to India earnings accumulated in prior years. In July 2020, the U.S. Treasury Department and the IRS released final regulations on Global Intangible Low-Taxed Income ("GILTI"), which became effective in September 2020, that reduced the tax applicable on our accumulated Indian earnings upon repatriation. As a result, during the third quarter of 2020, after a thorough analysis of the impact of these changes in law on the cost of earnings repatriation and considering our strategic decision to increase our investments to accelerate growth in various international markets and expand our global delivery footprint, we reversed our indefinite reinvestment assertion on Indian earnings accumulated in prior years and recorded a $140 million Tax on Accumulated Indian Earnings. The recorded income tax expense reflects the India withholding tax on unrepatriated Indian earnings, which were $5.2 billion as of December 31, 2019, net of applicable U.S. foreign tax credits. On October 28, 2020, our subsidiary in India remitted a dividend of $2.1 billion, which resulted in a net payment of $2.0 billion to its shareholders (non-Indian Cognizant entities), after payment of $106 million of India withholding tax. We are involved in an ongoing dispute with the ITD in connection with a previously disclosed 2016 share repurchase transaction undertaken by C TS India to repurchase shares from its shareholders (non-Indian Cognizant entities) valued at $2.8 billion. As a result of that transaction, which was undertaken pursuant to a plan approved by the High Court in Chennai, India, we previously paid $135 million in Indian income taxes - an amount we believe includes all the applicable taxes owed for this transaction under Indian law. In March 2018, we received a communication from the ITD asserting that the ITD is owed an additional 33 billion Indian rupees ($452 million at the December 31, 2020 exchange rate) on the 2016 transaction. Immediately thereafter, the ITD placed an attachment on certain of our India bank accounts. In addition to the dispute on the 2016 transaction, we are also involved in another ongoing dispute with the ITD relating to a 2013 transaction undertaken by CTS India to repurchase shares from its shareholders valued at $523 million (the two disputes collectively referred to as the "ITD Dispute"). In April 2018, the High Court admitted our writ petition for a stay of the actions of the ITD and lifted the ITD’s attachment on our bank accounts. As part of the interim stay order, we deposited 5 billion Indian rupees ($68 million at the December 31, 2020 exchange rate and $70 million at the December 31, 2019 exchange rate) representing 15% of the disputed tax amount related to the 2016 transaction, with the ITD. In addition, the Court also placed a lien on certain time deposits of CTS India in the amount of 28 billion Indian rupees ($384 million at the December 31, 2020 exchange rate and $393 million at the December 31, 2019 exchange rate), which is the remainder of the disputed tax amount related to the 2016 transaction. In June 2019, the High Court dismissed our previously admitted writ petitions on the ITD Dispute, holding that the Company must exhaust other remedies, such as pursuing the matter before other appellate bodies, for resolution of the ITD Dispute prior to intervention by the High Court. The High Court did not issue a ruling on the substantive issue of whether we owe additional tax as a result of either the 2016 or the 2013 transaction. In July 2019, we appealed the High Court’s orders before the Division Bench. In September 2019, the Division Bench partly allowed the Company’s appeal with respect to the 2016 transaction, but did not issue a ruling on the substantive issue of the tax implications of the transactions. In October 2019, we filed a SLP before the SCI with respect to the 2016 transaction. In March 2020, the SCI referred the case based on the 2016 transaction back to the ITD with directions to carry out the assessment following the due process of law. Further, until the conclusion of the assessment, the SCI maintained in place the lien on our 28 billion Indian rupees time deposit and did not order the release of the 5 billion Indian rupees deposit held by the ITD. In April 2020, we received an assessment from the ITD, which is consistent with its previous assertions regarding our 2016 transaction. In June 2020, we filed an appeal against this assessment. The ruling of the SCI and the ITD's assessment created additional uncertainty as to the timing of the resolution of this case and, as a result, in the first quarter of 2020 we reclassified the deposits under lien, which are considered restricted assets, and the deposit with the ITD to noncurrent assets. As of December 31, 2020 and 2019, the balance of deposits under lien was $405 million presented in "Long-term investments" and $414 million presented in "Short-term investments", respectively, including a portion of the interest previously earned. As of December 31, 2020 and 2019, the deposit with the ITD was $68 million presented in "Other noncurrent assets" and $70 million presented in "Other current assets", respectively. We believe we have paid all applicable taxes owed on both the 2016 and the 2013 transactions. Accordingly, we have not recorded any reserves for these matters as of December 31, 2020. The reconciliation between our effective income tax rate and the U.S. federal statutory rate were as follows for the years ended December 31: 2020 % 2019 % 2018 % (Dollars in millions) Tax expense, at U.S. federal statutory rate $ 440 21.0 $ 534 21.0 $ 587 21.0 State and local income taxes, net of federal benefit 52 2.5 59 2.3 56 2.0 Non-taxable income for Indian tax purposes (48) (2.3) (90) (3.5) (146) (5.2) Rate differential on foreign earnings 178 8.5 145 5.7 206 7.4 Net impact related to the implementation of the Tax Reform Act — — — — (5) (0.2) Net impact related to the India Tax Law — — 21 0.8 — — Recognition of previously unrecognized income tax benefits related to uncertain tax positions — — — — (12) (0.4) Credits and other incentives (51) (2.4) (57) (2.2) (19) (0.7) Reversal of indefinite reinvestment assertion 140 6.6 — — — — Other (7) (0.3) 31 1.2 31 1.1 Total provision for income taxes $ 704 33.6 $ 643 25.3 $ 698 25.0 The significant components of deferred income tax assets and liabilities recorded on the consolidated statements of financial position were as follows as of December 31: 2020 2019 (in millions) Deferred income tax assets: Net operating losses $ 36 $ 27 Revenue recognition 41 39 Compensation and benefits 259 171 MAT and credit carryforwards 109 307 Expenses not currently deductible 147 352 592 896 Less: valuation allowance (29) (24) Deferred income tax assets, net 563 872 Deferred income tax liabilities: Depreciation and amortization 198 187 Deferred costs 105 110 Other 21 25 Deferred income tax liabilities 324 322 Net deferred income tax assets $ 239 $ 550 At December 31, 2020, we had foreign and U.S. net operating loss carryforwards of approximately $55 million and $98 million, respectively. We have recorded valuation allowances on certain net operating loss carryforwards. As of December 31, 2020 and 2019, deferred income tax assets related to the MAT carryforwards were $98 million and $176 million, respectively. The calculation of the MAT includes all profits realized by our Indian subsidiaries and any MAT paid is creditable against future corporate income tax, subject to certain limitations. Our Indian subsidiaries are primarily export-oriented and are eligible for certain income tax holiday benefits granted by the government of India for export activities conducted within SEZs for periods of up to 15 years. Our SEZ income tax holiday benefits are currently scheduled to expire in whole or in part through the year 2028 and may be extended on a limited basis for an additional five years per unit if certain reinvestment criteria are met. Our Indian profits ineligible for SEZ benefits are subject to corporate income tax at the rate of 34.94%. In addition, all Indian profits, including those generated within SEZs, are subject to the MAT. The current rate of MAT is 17.47%. For the years ended December 31, 2020, 2019 and 2018, the effect of the income tax holidays granted by the Indian government was to reduce the overall income tax provision and increase net income by $48 million, $90 million and $146 million, respectively, and increase diluted EPS by $0.09, $0.16 and $0.25, respectively. In December 2019, the Government of India enacted the India Tax Law effective retroactively to April 1, 2019 that enables Indian companies to elect to be taxed at a lower income tax rate of 25.17%, as compared to the current income tax rate of 34.94%. Once a company elects into the lower income tax rate, a company may not benefit from any tax holidays associated with SEZs and certain other tax incentives, including MAT carryforwards, and may not reverse its election. Our current intent is to elect into the new tax regime once our MAT carryforwards are fully or substantially utilized. While our existing MAT carryforwards expire between March 2027 and March 2032, we expect to fully or substantially utilize our existing MAT carryforwards in or after the India financial year starting April 1, 2022. Our intent is based on a number of assumptions and financial projections. An election into the new tax law regime prior to utilization of our MAT carryforwards would result in a write-off of any remaining deferred income tax assets relating to the MAT carryforwards. As a result of the enactment of the India Tax Law, we recorded a one-time net income tax expense of $21 million in 2019, due to the revaluation to the lower income tax rate of our India net deferred income tax assets that are expected to reverse after we expect to elect into the new tax regime. We conduct business globally and file income tax returns in the United States, including federal and state, as well as various foreign jurisdictions. Tax years that remain subject to examination by the IRS are 2012 and onward, and years that remain subject to examination by state authorities vary by state. Years under examination by foreign tax authorities are 2001 and onward. In addition, transactions between our affiliated entities are arranged in accordance with applicable transfer pricing laws, regulations and relevant guidelines. As a result, and due to the interpretive nature of certain aspects of these laws and guidelines, we have pending applications for APAs before the taxing authorities in some of our most significant jurisdictions. We record incremental tax expense, based upon the more-likely-than-not standard, for any uncertain tax positions. In addition, when applicable, we adjust the previously recorded income tax expense to reflect examination results when the position is effectively settled or otherwise resolved. Our ongoing evaluations of the more-likely-than-not outcomes of the examinations and related tax positions require judgment and can result in adjustments that increase or decrease our effective income tax rate, as well as impact our operating results. The specific timing of when the resolution of each tax position will be reached is uncertain. Changes in unrecognized income tax benefits were as follows for the years ended December 31: 2020 2019 2018 (in millions) Balance, beginning of year $ 152 $ 117 $ 97 Additions based on tax positions related to the current year 28 22 8 Additions for tax positions of prior years 10 14 19 Additions for tax positions of acquired subsidiaries 3 — 6 Reductions for tax positions due to lapse of statutes of limitations — — (12) Reductions for tax positions of prior years — (1) — Settlements — — — Foreign currency exchange movement — — (1) Balance, end of year $ 193 $ 152 $ 117

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	In the normal course of business, we use foreign exchange forward and option contracts to manage foreign currency exchange rate risk. Derivatives may give rise to credit risk from the possible non-performance by counterparties. Credit risk is limited to the fair value of those contracts that are favorable to us. We have limited our credit risk by limi ting the amount of credit exposure with any one financial institution and conducting ongoing evaluation of the creditworthiness of the financial institutions with which we do business. In addition, all the assets and liabilities related to our foreign exchange derivative contracts set forth in the below table are subject to master netting arrangements, such as the International Swaps and Derivatives Association Master Agreement, with each individual counterparty. These master netting arrangements generally provide for net settlement of all outstanding contracts with the counterparty in the case of an event of default or a termination event. We have presented all the assets and liabilities related to our foreign exchange derivative contracts, as applicable, on a gross basis, with no offsets, in our consolidated statements of financial position. There is no financial collateral (including cash collateral) posted or received by us related to our foreign exchange derivative contracts. The following table provides information on the location and fair values of derivative financial instruments included in our consolidated statements of financial position as of December 31: 2020 2019 Designation of Derivatives Location on Statement of Assets Liabilities Assets Liabilities (in millions) Foreign exchange forward and option contracts – Designated as cash flow hedging instruments Other current assets $ 45 $ — $ 32 $ — Other noncurrent assets 26 — 8 — Accrued expenses and other current liabilities — — — 7 Other noncurrent liabilities — — — 2 Total 71 — 40 9 Foreign exchange forward contracts - Not designated as cash flow hedging instruments Other current assets 1 — 3 — Accrued expenses and other current liabilities — 1 — 1 Total 1 1 3 1 Total $ 72 $ 1 $ 43 $ 10 Cash Flow Hedges We have entered into a series of foreign exchange derivative contracts that are designated as cash flow hedges of Indian rupee denominated payments in India. These contracts are intended to partially offset the impact of movement of the Indian rupee against the U.S. dollar on future operating costs and are scheduled to mature each month during 2021 and 2022. The changes in fair value of these contracts are initially reported in "Accumulated other comprehensive income (loss)" in our consolidated statements of financial position and are subsequently reclassified to earnings within the captions "Cost of revenues" and "Selling, general and administrative expenses" in our consolidated statements of operations in the same period th at the forecasted Indian rupee denominated payments are recorded in earnings. As of December 31, 2020, we estimate that $35 million, net of tax, of the net gains relate d to derivatives designated as cash flow hedges reported in the caption "Accumulated other comprehensive income (loss)" in our consolidated statements of financial position is expected to be reclassified into earnings within the next 12 months. The notional value of our outstanding contracts by year of maturity and the net unrealized gains and losses included in the caption "Accumulated other comprehensive income (loss)" in our consolidated statements of financial position, for such contracts were as follows as of December 31: 2020 2019 (in millions) 2020 $ — $ 1,505 2021 1,470 883 2022 803 — Total notional value of contracts outstanding (1) $ 2,273 $ 2,388 Net unrealized gains included in accumulated other comprehensive income (loss), net of taxes $ 55 $ 26 (1) Includes $133 million notional value of option contracts as of December 31, 2020, with the remaining notional value related to forward contracts. The following table provides information on the location and amounts of pre-tax gains on our cash flow hedges for the year ended December 31: Change in Location of Net Derivative Net Gains Reclassified 2020 2019 2020 2019 (in millions) Foreign exchange forward and option contracts – Designated as cash flow hedging instruments $ 39 $ 39 Cost of revenues $ 3 $ 3 Selling, general and administrative expenses — 1 Total $ 3 $ 4 The activity related to the change in net unrealized gains and losses on our cash flow hedges included in "Accumulated other comprehensive income (loss)" in our consolidated statements of stockholders' equity is presented in Note 14 . Other Derivatives We use foreign exchange forward contracts to provide an economic hedge against balance sheet exposures to certain monetary assets and liabilities denominated in currencies other than the functional currency of our foreign subsidiaries, primarily th e Indian rupee, the British Pound and the Euro. We entered into foreign exchange forward contracts that are scheduled to mature in 2021. Realized gains or losses and changes in the fair value of these derivative financial instruments are recorded in the caption "Foreign currency exchange gains (losses), net" on our consolidated statements of operations. Additional information related to our outstanding foreign exchange forward contracts not designated as hedging instruments was as follows as of December 31: 2020 2019 Notional Fair Value Notional Fair Value (in millions) Contracts outstanding $ 637 $ — $ 702 $ 2 The following table provides information on the location and amounts of realized and unrealized pre-tax (losses) gains on our other derivative financial instruments for the year ended December 31: Location of Net (Losses) Gains Amount of Net (Losses) Gains 2020 2019 (in millions) Foreign exchange forward contracts - Not designated as hedging instruments Foreign currency exchange gains (losses), net $ (63) $ 8 The related cash flow impacts of all of our derivative activities are reflected as cash flows from operating activities.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	We measure our cash equivalents, certain investments, contingent consideration liabilities and foreign exchange forward and option contracts at fair value. The authoritative guidance defines fair value as the exit price, or the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants as of the measurement date. The authoritative guidance also establishes a fair value hierarchy that is intended to increase consistency and comparability in fair value measurements and related disclosures. The fair value hierarchy is based on inputs to valuation techniques that are used to measure fair value that are either observable or unobservable. Observable inputs reflect assumptions market participants would use in pricing an asset or liability based on market data obtained from independent sources while unobservable inputs reflect a reporting entity’s pricing based upon their own market assumptions. The fair value hierarchy consists of the following three levels: • Level 1 – Inputs are quoted prices in active markets for identical assets or liabilities. • Level 2 – Inputs are quoted prices for similar assets or liabilities in an active market, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable and market-corroborated inputs which are derived principally from or corroborated by observable market data. • Level 3 – Inputs are derived from valuation techniques in which one or more significant inputs or value drivers are unobservable. The following table summarizes our financial assets and (liabilities) measured at fair value on a recurring basis as of December 31, 2020: Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 209 $ — $ — $ 209 Time deposits — 203 — 203 Commercial paper — 200 — 200 Short-term investments: Time deposits — 3 — 3 Equity investment security 27 — — 27 Other current assets Foreign exchange forward and option contracts — 46 — 46 Long-term investments: Time deposits (1) — 405 — 405 Other noncurrent assets Foreign exchange forward and option contracts — 26 — 26 Accrued expenses and other current liabilities: Foreign exchange forward contracts — (1) — (1) Contingent consideration liabilities — — (11) (11) Other noncurrent liabilities Contingent consideration liabilities — — (43) (43) (1) Balance represents restricted time deposits. See Note 11 . The following table summarizes our financial assets and (liabilities) measured at fair value on a recurring basis as of December 31, 2019: Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 1,646 $ — $ — $ 1,646 Short-term investments: Time deposits (1) — 466 — 466 Equity investment security 26 — — 26 Other current assets: Foreign exchange forward contracts — 35 — 35 Other noncurrent assets: Foreign exchange forward contracts — 8 — 8 Accrued expenses and other current liabilities: Foreign exchange forward contracts — (8) — (8) Contingent consideration liabilities — — (8) (8) Other noncurrent liabilities: Foreign exchange forward contracts — (2) — (2) Contingent consideration liabilities — — (30) (30) (1) Includes $414 million in restricted time deposits. See Note 11 The following table summarizes the changes in Level 3 contingent consideration liabilities: 2020 2019 (in millions) Beginning balance $ 38 $ 23 Initial measurement recognized at acquisition 42 33 Change in fair value recognized in SG&A expenses (23) (4) Payments (3) (14) Ending balance $ 54 $ 38 We measure the fair value of money market funds based on quoted prices in active markets for identical assets and measure the fair value of our equity security based on the published daily net asset value at which investors can freely subscribe to or redeem from the fund. The fair value of commercial paper is measured based on relevant trade data, dealer quotes, or model-driven valuations using significant inputs derived from or corroborated by observable market data, such as yield curves and credit spreads. The carrying value of the time deposits approximated fair value as of December 31, 2020 and 2019. We estimate the fair value of each foreign exchange forward contract by using a present value of expected cash flows model. This model calculates the difference between the current market forward price and the contracted forward price for each foreign exchange contract and applies the difference in the rates to each outstanding contract. The market forward rates include a discount and credit risk factor. We estimate the fair value of each foreign exchange option contract by using a variant of the Black-Scholes model. This model uses present value techniques and reflects the time value and intrinsic value based on observable market rates. We estimate the fair value of our contingent consideration liabilities associated with our acquisitions using a variation of the income approach, which utilizes one or more significant inputs that are unobservable. This approach calculates the fair value of such liabilities based on the probability-weighted expected performance of the acquired entity against the target performance metric, discounted to present value when appropriate. During the years ended December 31, 2020, 2019 and 2018 there were no transfers among Level 1, Level 2 or Level 3 financial assets and liabilities.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Income	Changes in "Accumulated other comprehensive income (loss)" by component were as follows for the year ended December 31, 2020: 2020 Before Tax Tax Net of Tax (in millions) Foreign currency translation adjustments: Beginning balance $ (63) $ (1) $ (64) Change in foreign currency translation adjustments 119 — 119 Ending balance $ 56 $ (1) $ 55 Unrealized gains on cash flow hedges: Beginning balance $ 31 $ (5) $ 26 Unrealized gains arising during the period 39 (8) 31 Reclassifications of net (gains) to: Cost of revenues (3) 1 (2) Net change 36 (7) 29 Ending balance $ 67 $ (12) $ 55 Accumulated other comprehensive income (loss): Beginning balance $ (32) $ (6) $ (38) Other comprehensive income (loss) 155 (7) 148 Ending balance $ 123 $ (13) $ 110 Changes in "Accumulated other comprehensive income (loss)" by component were as follows for the years ended December 31, 2019 and 2018: 2019 2018 Before Tax Tax Net of Tax Before Tax Tax Net of Tax (in millions) Foreign currency translation adjustments: Beginning balance $ (108) $ 5 $ (103) $ (38) $ — $ (38) Change in foreign currency translation adjustments 45 (6) 39 (70) 5 (65) Ending balance $ (63) $ (1) $ (64) $ (108) $ 5 $ (103) Unrealized (losses) on available-for-sale investment securities: Beginning balance $ (12) $ 4 $ (8) $ (11) $ 4 $ (7) Cumulative effect of change in accounting principle — — — — (1) (1) Net unrealized gains (losses) arising during the period 13 (4) 9 (5) 2 (3) Reclassification of net (gains) losses to Other, net (1) — (1) 4 (1) 3 Net change 12 (4) 8 (1) — (1) Ending balance $ — $ — $ — $ (12) $ 4 $ (8) Unrealized (loses) gains on cash flow hedges: Beginning balance $ (4) $ 1 $ (3) $ 154 $ (39) $ 115 Unrealized gains (losses) arising during the period 39 (7) 32 (87) 23 (64) Reclassifications of net gains to: Cost of revenues (3) 1 (2) (61) 15 (46) SG&A expenses (1) — (1) (10) 2 (8) Net change 35 (6) 29 (158) 40 (118) Ending balance $ 31 $ (5) $ 26 $ (4) $ 1 $ (3) Accumulated other comprehensive income (loss): Beginning balance $ (124) $ 10 $ (114) $ 105 $ (35) $ 70 Other comprehensive income (loss) 92 (16) 76 (229) 45 (184) Ending balance $ (32) $ (6) $ (38) $ (124) $ 10 $ (114)

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	We are involved in various claims and legal proceedings arising in the ordinary course of business. We accrue a liability when a loss is considered probable and the amount can be reasonably estimated. When a material loss contingency is reasonably possible but not probable, we do not record a liability, but instead disclose the nature and the amount of the claim, and an estimate of the loss or range of loss, if such an estimate can be made. Legal fees are expensed as incurred. While we do not expect that the ultimate resolution of any existing claims and proceedings (other than the specific matters described below, if decided adversely), individually or in the aggregate, will have a material adverse effect on our financial position, an unfavorable outcome in some or all of these proceedings could have a material adverse impact on results of operations or cash flows for a particular period. This assessment is based on our current understanding of relevant facts and circumstances. As such, our view of these matters is subject to inherent uncertainties and may change in the future. On January 15, 2015, Syntel sued TriZetto and Cognizant in the United States District Court for the Southern District of New York. Syntel’s complaint alleged breach of contract against TriZetto, and tortious interference and misappropriation of trade secrets against Cognizant and TriZetto, stemming from Cognizant’s hiring of certain former Syntel employees. Cognizant and TriZetto countersued on March 23, 2015, for breach of contract, misappropriation of trade secrets and tortious interference, based on Syntel’s misuse of TriZetto confidential information and abandonment of contractual obligations. Cognizant and TriZetto subsequently added federal Defend Trade Secrets Act and copyright infringement claims for Syntel’s misuse of TriZetto’s proprietary technology. The parties’ claims were narrowed by the court and the case was tried before a jury, which on October 27, 2020 returned a verdict in favor of Cognizant in the amount of $854 million, including $570 million in punitive damages. We expect Syntel to app eal the decision and thus we will not record the gain in our financial statements until it becomes realizable. On February 28, 2019, a ruling of the SCI interpreting the India Defined Contribution Obligation altered historical understandings of the obligation, extending it to cover additional portions of the employee’s income. As a result, the ongoing contributions of our affected employees and the Company were required to be increased. In the first quarter of 2019, we accrued $117 million with respect to prior periods, assuming retroactive application of the Supreme Court’s ruling, in "Selling, general and administrative expenses" in our consolidated statement of operations. There is significant uncertainty as to how the liability should be calculated as it is impacted by multiple variables, including the period of assessment, the application with respect to certain current and former employees and whether interest and penalties may be assessed. Since the ruling, a variety of trade associations and industry groups have advocated to the Indian government, highlighting the harm to the information technology sector, other industries and job growth in India that would result from a retroactive application of the ruling. It is possible the Indian government will review the matter and there is a substantial question as to whether the Indian government will apply the SCI’s ruling on a retroactive basis. As such, the ultimate amount of our obligation may be materially different from the amount accrued. On October 5, 2016, October 27, 2016 and November 18, 2016, three putative securities class action complaints were filed in the United States District Court for the District of New Jersey, naming us and certain of our current and former officers as defendants. These complaints were consolidated into a single action and on April 7, 2017, the lead plaintiffs filed a consolidated amended complaint on behalf of a putative class of persons and entities who purchased our common stock during the period between February 27, 2015 and September 29, 2016, naming us and certain of our current and former officers as defendants and alleging violations of the Exchange Act, based on allegedly false or misleading statements related to potential violations of the FCPA, our business, prospects and operations, and the effectiveness of our internal controls over financial reporting and our disclosure controls and procedures. The lead plaintiffs seek an award of compensatory damages, among other relief, and their reasonable costs and expenses, including attorneys’ fees. Defendants filed a motion to dismiss the consolidated amended complaint on June 6, 2017. On August 8, 2018, the United States District Court for the District of New Jersey issued an order which granted the motion to dismiss in part, including dismissal of all claims against current officers of the Company, and denied them in part. On September 7, 2018, we filed a motion in the United States District Court for the District of New Jersey to certify the August 8, 2018 order for immediate appeal to the United States Court of Appeals for the Third Circuit pursuant to 28 U.S.C. § 1292(b). On October 18, 2018, the District Court issued an order granting our motion, and staying the action pending the outcome of our appeal petition to the Third Circuit. On October 29, 2018, we filed a petition for permission to appeal with the United States Court of Appeals for the Third Circuit. On March 6, 2019, the Third Circuit denied our petition without prejudice. In an order dated March 19, 2019, the District Court directed the lead plaintiffs to provide the defendants with a proposed amended complaint. On April 26, 2019, lead plaintiffs filed their second amended complaint. We filed a motion to dismiss the second amended complaint on June 10, 2019. On June 7, 2020, the District Court issued an order denying our motion to dismiss the second amended complaint. On July 10, 2020, we filed our answer to the second amended complaint. On July 23, 2020, the DOJ filed a motion on consent for leave to intervene and to stay all discovery through the conclusion of the criminal proceedings in United States v. Gordon J. Coburn and Steven Schwartz, Crim. No. 19-120 (KM), except for documents produced by us to the DOJ in connection with those criminal proceedings. On July 24, 2020, the District Court granted the DOJ’s motion; and on that same day, we filed a motion in the District Court to certify the June 7, 2020 order for immediate appeal to the Third Circuit pursuant to 28 U.S.C. 1292(b), which motion is now fully briefed. On October 31, 2016, November 15, 2016 and November 18, 2016, three putative shareholder derivative complaints were filed in New Jersey Superior Court, Bergen County, naming us, all of our then current directors and certain of our current and former officers as defendants. These actions were consolidated in an order dated January 24, 2017. The complaints assert claims for breach of fiduciary duty, corporate waste, unjust enrichment, abuse of control, mismanagement, and/or insider selling by defendants. On March 16, 2017, the parties filed a stipulation deferring all further proceedings pending a final, non-appealable ruling on the then anticipated motion to dismiss the consolidated putative securities class action. On April 26, 2017, in lieu of ordering the stipulation filed by the parties, the New Jersey Superior Court deferred further proceedings by dismissing the consolidated putative shareholder derivative litigation without prejudice but permitting the parties to file a motion to vacate the dismissal in the future. On February 22, 2017, April 7, 2017 and May 10, 2017, three additional putative shareholder derivative complaints alleging similar claims were filed in the United States District Court for the District of New Jersey, naming us and certain of our current and former directors and officers as defendants. These complaints asserted claims similar to those in the previously-filed putative shareholder derivative actions. In an order dated June 20, 2017, the United States District Court for the District of New Jersey consolidated these actions into a single action, appointed lead plaintiff and lead counsel, and stayed all further proceedings pending a final, non-appealable ruling on the motions to dismiss the consolidated putative securities class action. On October 30, 2018, lead plaintiff filed a consolidated verified derivative complaint. On March 11, 2019, a seventh putative shareholder derivative complaint was filed in the United States District Court for the District of New Jersey, naming us, certain of our current and former directors, and certain of our current and former officers as defendants. The complaint in that action asserts claims similar to those in the previously-filed putative shareholder derivative actions. On May 14, 2019, the United States District Court for the District of New Jersey approved a stipulation that (i) consolidated this action with the putative shareholder derivative suits that were previously filed in the United States District Court for the District of New Jersey; and (ii) stayed all of these suits pending order on the motion to dismiss the second amended complaint in the securities class action. On August 3, 2020, lead plaintiffs filed an amended complaint. We are presently unable to predict the duration, scope or result of the consolidated putative securities class action, the putative shareholder derivative actions or any other lawsuits. As such, we are presently unable to develop a reasonable estimate of a possible loss or range of losses, if any, and thus have not recorded any accruals related to these matters. While the Company intends to defend the lawsuits vigorously, these lawsuits and any other related lawsuits are subject to inherent uncertainties, the actual cost of such litigation will depend upon many unknown factors and the outcome of the litigation is necessarily uncertain. We have indemnification and expense advancement obligations pursuant to our bylaws and indemnification agreements with respect to certain current and former members of senior management and the Company’s directors. In connection with the matters that were the subject of our previously disclosed internal investigation, the DOJ and SEC investigations and the related litigation, we have received and expect to continue to receive requests under such indemnification agreements and our bylaws to provide funds for legal fees and other expenses. We have expensed such costs incurred through December 31, 2020. We have maintained directors and officers insurance and have recorded an insurance receivable of $7 million and $20 million as of December 31, 2020 and 2019, respectively, in "Other current assets" o n our consolidated statement of financial position related to the recovery of a portion of the indemnification expenses and costs related to the putative securities class action complaints. We are unable to make a reliable estimate of the eventual cash flows by period related to the indemnification and expense advancement obligations described here. See Note 11 for information relating to the ITD Dispute. Many of our engagements involve projects that are critical to the operations of our clients’ business and provide benefits that are difficult to quantify. Any failure in a client’s systems or our failure to meet our contractual obligations to our clients, including any breach involving a client’s confidential information or sensitive data, or our obligations under applicable laws or regulations could result in a claim for substantial damages against us, regardless of our responsibility for such failure. Although we attempt to contractually limit our liability for damages arising from negligent acts, errors, mistakes, or omissions in rendering our services, there can be no assurance that the limitations of liability set forth in our contracts will be enforceable in all instances or will otherwise protect us from liability for damages. Although we have general liability insurance coverage, including coverage for errors or omissions, there can be no assurance that such coverage will cover all types of claims, continue

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2020
Retirement Benefits, Description [Abstract]
Employee Benefits	We contribute to defined contribution plans in the United States and Europe, including 401(k) savings and supplemental retirement plans in the United States. Total expenses for our contributions to these plans were $118 million, $117 million and $108 million for the years ended December 31, 2020, 2019 and 2018, respectively. We maintain employee benefit plans that cover substantially all India-based employees. The employees’ provident fund, pension and family pension plans are statutorily defined contribution retirement benefit plans. Under the plans, employees contribute up to 12.0% of their eligible compensation, which is matched by an equal contribution by the Company. For these plans, we recognized a contribution expense of $98 million, $101 million and $88 million for the years ended December 31, 2020, 2019 and 2018, respectively. On February 28, 2019, a ruling of the SCI altered historical understandings of the obligation under these plans, extending them to cover additional portions of the employee’s income. In the first quarter of 2019, we accrued $117 million with respect to prior periods, assuming retroactive application of the SCI’s ruling, in "Selling, general and administrative expenses" in our consolidated statements of operations. See Note 15 for further information. We also maintain a gratuity plan in India that is a statutory post-employment benefit plan providing defined lump sum benefits. We make annual contributions to the employees’ gratuity fund established with a government-owned insurance corporation to fund a portion of the estimated obligation. Accordingly, our liability for the gratuity plan reflected the undiscounted benefit obligation payable as of the balance sheet date, which was based upon the employees’ salary and years of service. As of December 31, 2020 and 2019, the amount accrued under the gratuity plan was $124 million and $135 million, which is net of fund assets of $186 million and $160 million, respectively . Expense recognized by us was $35 million, $38 million and $53 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Compensation Plans	The Company's 2017 Incentive Plan and the Purchase Plan provide for the issuance of up to 48.8 million (plus any shares underlying outstanding awards that are forfeited under the 2009 Incentive Plan) and 40.0 million shares, respectively, of Class A common stock to eligible employees. The 2017 Incentive Plan does not affect any awards outstanding under the 2009 Incentive Plan. As of December 31, 2020, we have 28.8 million and 5.9 million shares available for grant under the 2017 Incentive Plan and the Purchase Plan, respectively. The allocation of total stock-based compensation expense between cost of revenues and selling, general and administrative expenses as well as the related income tax benefit were as follows for the three years ended December 31: 2020 2019 2018 (in millions) Cost of revenues $ 51 $ 54 $ 62 SG&A expenses 181 163 205 Total stock-based compensation expense $ 232 $ 217 $ 267 Income tax benefit $ 48 $ 39 $ 66 Restricted Stock Units and Performance Stock Units We granted RSUs that vest proportionately in quarterly or annual installments ranging from one year to four years to employees, including our executive officers. Stock-based compensation expense relating to RSUs is recognized on a straight-line basis over the requisite service period. A summary of the activity for RSUs granted under our stock-based compensation plans as of December 31, 2020 and changes during the year then ended is presented below: Number of Weighted Average Unvested at January 1, 2020 4.5 $ 67.07 Granted 3.9 61.85 Vested (3.0) 65.42 Forfeited (1.0) 64.91 Unvested at December 31, 2020 4.4 $ 64.09 The weighted-average grant date fair value of RSUs granted in 2020, 2019 and 2018 was $61.85, $64.12 and $74.94, respectively. As of December 31, 2020, $247 million of total remaining unrecognized stock-based compensation cost related to RSUs is expected to be recognized over the weighted-average remaining requisite service period of 1.8 years. We granted PSUs that vest over periods ranging from one year to four years to employees, including our executive officers. The vesting of PSUs is contingent on both meeting certain financial performance targets and continued service. A summary of the activity for PSUs granted under our stock-based compensation plans as of December 31, 2020 and changes during the year then ended is presented below. The presentation reflects the number of PSUs at the maximum performance milestones. Number of Weighted Average Unvested at January 1, 2020 2.0 $ 69.73 Granted 1.9 62.00 Vested (0.2) 60.63 Forfeited (0.9) 67.59 Adjustment at the conclusion of the performance measurement period (1.1) 70.67 Unvested at December 31, 2020 1.7 $ 62.60 The weighted-average grant date fair value of PSUs granted in 2020, 2019 and 2018 was $62.00, $70.77 and $81.98, respectively. As of December 31, 2020, $34 million of the total remaining unrecognized stock-based compensation cost related to PSUs is expected to be recognized over the weighted-average remaining requisite service period of 2.0 years. All RSUs and PSUs have dividend equivalent rights, which entitle holders to the same dividend value per share as holders of common stock. Dividend equivalent rights are subject to the same vesting and other terms and conditions as the corresponding unvested RSUs and PSUs and are accumulated and paid when the underlying shares vest. The Purchase Plan The Purchase Plan provides for eligible employees to purchase shares of Class A common stock at a price of 90% of the lesser of: (a) the fair market value of a share of Class A common stock on the first date of the purchase period or (b) the fair market value of a share of Class A common stock on the last date of the purchase period. Stock-based compensation expense for the Purchase Plan is recognized over the vesting period of three months on a straight-line basis. The fair values of the options granted under the Purchase Plan, were estimated at the date of grant during the years ended December 31, 2020, 2019, and 2018 based upon the following assumptions and were as follows: 2020 2019 2018 Dividend yield 1.1 % 1.3 % 1.0 % Weighted average volatility factor 35.9 % 24.9 % 21.0 % Weighted average risk-free interest rate 0.6 % 2.2 % 1.9 % Weighted average expected life (in years) 0.25 0.25 0.25 Weighted average grant date fair value $ 9.38 $ 9.82 $ 10.87 During the year ended December 31, 2020, we issued 3.0 million shares of Class A common stock under the Purchase Plan with a total fair value of approximately $28 million.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	In 2018, we provided $100 million of initial funding to the Cognizant U.S. Foundation. The expense was reported in the caption "Selling, general and administrative expenses" in our consolidated statement of operations. Additionally, two of our executive officers served as directors of the Cognizant U.S. Foundation in 2020, 2019 and 2018.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Segment Information	Our reportable segments are: • Financial Services, which consists of our banking and insurance operating segments; • Healthcare, which consists of our healthcare and life sciences operating segments; • Products and Resources, which consists of our retail and consumer goods; manufacturing, logistics, energy, and utilities; and travel and hospitality operating segments; and • Communications, Media and Technology, which includes our communications and media operating segment and our technology operating segment. Our client partners, account executives and client relationship managers are aligned in accordance with the specific industries they serve. Our chief operating decision maker evaluates the Company's performance and allocates resources based on segment revenues and operating profit. Segment operating profit is defined as income from operations before unallocated costs. Generally, operating expenses for each operating segment have similar characteristics and are subject to the same factors, pressures and challenges. However, the economic environment and its effects on industries served by our operating segments may affect revenues and operating expenses to differing degrees. Expenses included in segment operating profit consist principally of direct selling and delivery costs (including stock-based compensation expense) as well as a per employee charge for use of our global delivery centers and infrastructure. Certain SG&A expenses, the excess or shortfall of incentive-based compensation for commercial and delivery employees as compared to target, restructuring costs, COVID-19 Charges, costs related to the ransomware attack, a portion of depreciation and amortization and the impact of the settlements of our cash flow hedges are not allocated to individual segments in internal management reports used by the chief operating decision maker. Accordingly, such expenses are excluded from segment operating profit and are included below as “unallocated costs” and adjusted against our total income from operations. The incremental accrual related to the India Defined Contribution Obligation recorded in 2019 has been excluded from segment operating profits for the year ended December 31, 2019. These costs are included in "unallocated costs" in the table below. Additionally, management has determined that it is not practical to allocate identifiable assets by segment, since such assets are used interchangeably among the segments. For revenues by reportable segment and geographic area see Note 2 . Segment operating profits by reportable segment were as follows: 2020 2019 2018 (in millions) Financial Services $ 1,449 $ 1,605 $ 1,713 Healthcare 1,383 1,261 1,416 Products and Resources 1,078 1,028 1,023 Communications, Media and Technology 794 732 692 Total segment operating profit 4,704 4,626 4,844 Less: unallocated costs 2,590 2,173 2,043 Income from operations $ 2,114 $ 2,453 $ 2,801 Geographic Area Information Long-lived assets by geographic area are as follows: 2020 2019 2018 (in millions) Long-lived Assets: (1) North America (2) $ 399 $ 445 $ 436 Europe 88 104 105 Rest of World (3) 764 760 853 Total $ 1,251 $ 1,309 $ 1,394 (1) Long-lived assets include property and equipment, net of accumulated depreciation and amortization. (2) Substantially all relates to the United States. (3) Substantially all relates to India.

Valuation And Qualifying Accoun

Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation And Qualifying Accounts	Valuation and Qualifying Accounts For the Years Ended December 31, 2020, 2019 and 2018 (in millions) Description Balance at Charged to Charged to Deductions Balance at (in millions) Warranty accrual: 2020 $ 33 $ 32 $ — $ 33 $ 32 2019 $ 32 $ 33 $ — $ 32 $ 33 2018 $ 30 $ 32 $ — $ 30 $ 32 Valuation allowance—deferred income tax assets: 2020 $ 24 $ 5 $ — $ — $ 29 2019 $ 11 $ 15 $ — $ 2 $ 24 2018 $ 10 $ 1 $ — $ — $ 11

Subsequent Events (Notes)

Subsequent Events (Notes)	12 Months Ended
	Dec. 31, 2020
Subsequent Event [Line Items]
Subsequent Events [Text Block]	Dividend On February 3, 2021, our Board of Directors approved the Company's declaration of a $0.24 per share dividend with a record date of February 18, 2021 and a payment date of February 26, 2021. Acquisitions In January 2021, we completed the acquisition of Linium for a preliminary purchase price of $85 million. Linium is a cloud transformation consultancy group specializing in the ServiceNow platform and solutions for smart digital enterprise workflows, acquired to broaden our enterprise service management capabilities. In January 2021, we entered into an agreement to acquire Servian for a preliminary purchase price of $240 million. Servian is an Australia-based enterprise transformation consultancy specializing in data analytics, AI, digital services, experience design and cloud, which is expected to enhance our digital portfolio and market presence in Australia and New Zealand. The transaction is expected to close during the first quarter of 2021.

Business Description and Summ_2

Business Description and Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation And Principles of Consolidation	Basis of Presentation, Principles of Consolidation and Use of Estimates. The consolidated financial statements are presented in accordance with GAAP and reflect the consolidated financial position, results of operations, comprehensive income and cash flows of our consolidated subsidiaries for all periods presented. All intercompany balances and transactions have been eliminated in consolidation.
Cash And Cash Equivalents And Investments	Cash and Cash Equivalents and Investments. Cash and cash equivalents consist of all cash balances, including money market funds, certificates of deposits and commercial paper that have a maturity, at the date of purchase, of 90 days or less. We determine the appropriate classification of our investments in marketable securities at the date of purchase and reevaluate such designation at each balance sheet date. Our held-to-maturity investment securities are financial instruments for which we have the intent and ability to hold to maturity and we classify these securities with maturities less than one year as short-term investments. Any held-to-maturity investment securities with maturities beyond one year from the balance sheet date are classified as noncurrent. Held-to-maturity securities are reported at amortized cost. Interest and amortization of premiums and discounts for debt securities are included in interest income.
Short-Term Financial Assets And Liabilities	Financial Assets and Liabilities. Cash and certain cash equivalents, time deposits, trade receivables, accounts payable and other accrued liabilities are short-term in nature and, accordingly, their carrying values approximate fair value.
Property And Equipment	Property and Equipment. Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is calculated on a straight-line basis over the estimated useful lives of the assets. Leasehold improvements are amortized on a straight-line basis over the shorter of the term of the lease or the estimated useful life of the asset. Deposits paid towards acquisition of long-lived assets and the cost of assets not put in use by the balance sheet date are disclosed under the caption "Capital work-in-progress" in Note 6 .
Lessee, Leases	Leases. Our lease asset classes primarily consist of operating leases for office space, data centers and IT equipment. At inception of a contract, we determine whether a contract contains a lease, and if a lease is identified, whether it is an operating or finance lease. In determining whether a contract contains a lease we consider whether (1) we have the right to obtain substantially all of the economic benefits from the use of the asset throughout the term of the contract, (2) we have the right to direct how and for what purpose the asset is used throughout the term of the contract and (3) we have the right to operate the asset throughout the term of the contract without the lessor having the right to change the terms of the contract. Some of our lease agreements contain both lease and non-lease components that we account for as a single lease component for all of our lease asset classes. Our ROU lease assets represent our right to use an underlying asset for the lease term and may include any advance lease payments made and any initial direct costs and exclude lease incentives. Our lease liabilities represent our obligation to make lease payments arising from the terms of the lease. ROU lease assets and lease liabilities are recognized at the commencement of the lease and are calculated using the present value of lease payments over the lease term. Typically, our lease agreements do not provide sufficient detail to arrive at an implicit interest rate. Therefore, we use our estimated country-specific incremental borrowing rate based on information available at the commencement date of the lease to calculate the present value of the lease payments. In estimating our country-specific incremental borrowing rates, we consider market rates of comparable collateralized borrowings for similar terms. Our lease terms may include the option to extend or terminate the lease before the end of the contractual lease term. Our ROU lease assets and lease liabilities include these options when it is reasonably certain that they will be exercised. A portion of our real estate lease costs is subject to annual changes in the CPI. The changes to the CPI are treated as variable lease payments and are recognized in the period in which the obligation for those payments is incurred. Other variable lease costs primarily relate to adjustments for common area maintenance, utilities, property tax and lease concessions due to the COVID-19 pandemic. These variable costs are recognized in the period in which the obligation for those payments is incurred. We elect not to recognize ROU assets and lease liabilities for short-term leases with a term equal to or less than 12 months. We recognize the lease payments in our income statement on a straight-line basis over the lease term and variable lease payments in the period in which the obligation for those payments is incurred. Both ROU assets and finance lease assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the related asset group may not be recoverable.
Internal Use Software	Internal Use Software. We capitalize certain costs that are incurred to purchase, develop and implement internal-use software during the application development phase, which primarily include coding, testing and certain data conversion activities. Capitalized costs are amortized on a straight-line basis over the useful life of the software. Costs incurred in performing planning and post-implementation activities are expensed as incurred.
Software to be Sold Leased or Marketed	Software to be Sold, Leased or Marketed. We capitalize costs incurred after technological feasibility is reached but before software is available for general release to clients, which primarily include coding and testing activities. Once the product is ready for general release, capitalized costs are amortized over the useful life of the software.
Business Combinations	Business Combinations. We account for business combinations using the acquisition method, which requires the identification of the acquirer, the determination of the acquisition date and the allocation of the purchase price paid by the acquirer to the identifiable tangible and intangible assets acquired, the liabilities assumed, including any contingent consideration and any noncontrolling interest in the acquiree at their acquisition date fair values. Goodwill represents the excess of the purchase price over the fair value of net assets acquired, including the amount assigned to identifiable intangible assets. Identifiable intangible assets with finite lives are amortized over their expected useful lives. Acquisition-related costs are expensed in the periods in which the costs are incurred. The results of operations of acquired businesses are included in our consolidated financial statements from the acquisition date . During the fourth quarter of 2019, the Company adjusted the allocation of the purchase price of certain prior period acquisitions that included revenue contracts with the sellers of the acquired businesses. As a result, we recorded a balance sheet adjustment to decrease total assets (primarily impacting intangible assets, goodwill and deferred income taxes) and total liabilities (primarily impacting deferred revenue) by approximately $70 million each. The impact of the adjustment to our
Equity Method Investments	Equity Method Investments. Equity investments that give us the ability to exercise significant influence, but not control, over an investee are accounted for using the equity method of accounting and recorded in the caption "Long-term investments" on our consolidated statements of financial position. Equity method investments are initially recorded at cost. We periodically review the carrying value of our equity method investments to determine if there has been an other-than-temporary decline in the carrying value. The investment balance is increased to reflect contributions and our share of earnings and decreased to reflect our share of losses, distributions, and other-than-temporary impairments. The Company's proportionate share of the net income or loss of the investee is recorded in the caption "Income (loss) from equity method investments" on our consolidated statements of operations.
Long-Lived Assets And Finite-Lived Intangibles	Long-lived Assets and Finite-lived Intangible Assets. We review long-lived assets and certain finite-lived identifiable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable. The carrying amount may not be recoverable when the sum of undiscounted expected future cash flows is less than the carrying amount of such asset groups. The impairment loss is determined as the amount by which the carrying amount of the asset group exceeds its fair value. Intangible assets consist primarily of customer relationships and developed technology, which are being amortized on a straight-line basis over their estimated useful lives.
Goodwill And Indefinite-Lived intangibles	Goodwill and Indefinite-lived Intangible Assets. We evaluate goodwill and indefinite-lived intangible assets for impairment at least annually, or as circumstances warrant. Goodwill is evaluated at the reporting unit level by comparing the fair value of the reporting unit with its carrying amount including goodwill. An impairment of goodwill exists if the carrying amount of the reporting unit exceeds its fair value. The impairment loss is the amount by which the carrying amount exceeds the reporting unit’s fair value, limited to the total amount of goodwill allocated to that reporting unit. For indefinite-lived intangible assets, if our annual qualitative assessment indicates that it is more-likely-than-not that an indefinite-lived intangible asset is impaired, we test the assets for impairment by comparing the fair value of such assets to their carrying value. If an impairment is indicated, a write down to the fair value of indefinite-lived intangible asset is recorded.
Stock Repurchase Program	Stock Repurchase Program. Under the Board of Directors authorized stock repurchase program, the Company is authorized to repurchase its Class A common stock through open market purchases, including under a 10b5-1 Plan, or in private transactions, including through ASR agreements entered into with financial institutions, in accordance with applica ble federal securities laws. We account for the repurchased shares as constructively retired. Shares are returned to the status of authorized and unissued shares at the time of repurchase or in the periods they are delivered if repurchased under an ASR. To reflect share repurchases in the consolidated statements of financial position, we (1) reduce common stock for the par value of the shares, (2) reduce additional paid-in capital for the amount in excess of par during the period in which the shares are repurchased and (3) record any residual amount in excess of available additional paid-in capital to retained earnings. Upfront payments related to ASRs are accounted for as a reduction to stockholders’ equity in the consolidated statements of financial position in the period the payments are made.
Revenue Recognition	Revenue Recognition. We recognize revenues as we transfer control of deliverables (products, solutions and services) to our clients in an amount reflecting the consideration to which we expect to be entitled. To recognize revenues, we apply the following five step approach: (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 to the performance obligations in the contract, and (5) recognize revenues when a performance obligation is satisfied. We account for a contract when it has approval and commitment from all parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. We apply judgment in determining the customer’s ability and intention to pay based on a variety of factors including the customer’s historical payment experience. For performance obligations where control is transferred over time, revenues are recognized based on the extent of progress towards completion of the performance obligation. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the deliverables to be provided. Revenues related to fixed-price contracts for application development and systems integration services, consulting or other technology services are recognized as the service is performed using the cost to cost method, under which the total value of revenues is recognized on the basis of the percentage that each contract’s total labor cost to date bears to the total expected labor costs. Revenues related to fixed-price application maintenance, testing and business process services are recognized based on our right to invoice for services performed for contracts in which the invoicing is representative of the value being delivered. If our invoicing is not consistent with the value delivered, revenues are recognized as the service is performed based on the cost to cost method described above. The cost to cost method requires estimation of future costs, which is updated as the project progresses to reflect the latest available information; such estimates and changes in estimates involve the use of judgment. The cumulative impact of any revision in estimates is reflected in the financial reporting period in which the change in estimate becomes known and any anticipated losses on contracts are recognized immediately, where appropriate. Revenues related to fixed-price hosting and infrastructure services are recognized based on our right to invoice for services performed for contracts in which the invoicing is representative of the value being delivered. If our invoicing is not consistent with the value delivered, revenues are recognized on a straight-line basis unless revenues are earned and obligations are fulfilled in a different pattern. The revenue recognition method applied to the types of contracts described above provides the most faithful depiction of performance towards satisfaction of our performance obligations; for example, the cost to cost method is used when the value of services provided to the customer is best represented by the costs expended to deliver those services. Revenues related to our time-and-materials, transaction-based or volume-based contracts are recognized over the period the services are provided either using an output method such as labor hours, or a method that is otherwise consistent with the way in which value is delivered to the customer. Revenues related to our non-hosted software license arrangements that do not require significant modification or customization of the underlying software are recognized when the software is delivered as control is transferred at a point in time. For software license arrangements that require significant functionality enhancements or modification of the software, revenues for the software license and related services are recognized as the services are performed in accordance with the methods applicable to application development and systems integration services described above. In software hosting arrangements, the rights provided to the customer, such as ownership of a license, contract termination provisions and the feasibility of the client to operate the software, are considered in determining whether the arrangement includes a license or a service. Sales and usage-based fees promised in exchange for licenses of intellectual property are not recognized as revenue until the uncertainty related to the variable amounts is resolved. Revenues related to software maintenance and support are generally recognized on a straight-line basis over the contract period. Incentive revenues, volume discounts, or any other form of variable consideration is estimated using either the sum of probability weighted amounts in a range of possible consideration amounts (expected value) or the single most likely amount in a range of possible consideration amounts (most likely amount), depending on which method better predicts the amount of consideration to which we may be entitled. We include in the transaction price variable consideration only to the extent it is probable that a significant reversal of revenues recognized will not occur when the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether and when to include estimated amounts in the transaction price may involve judgment and are based largely on an assessment of our anticipated performance and all information that is reasonably available to us. Revenues also include the reimbursement of out-of-pocket expenses. Our warranties generally provide a customer with assurance that the related deliverable will function as the parties intended because it complies with agreed-upon specifications and is therefore not considered an additional performance obligation in the contract. We may enter into arrangements that consist of multiple performance obligations. Such arrangements may include any combination of our deliverables. To the extent a contract includes multiple promised deliverables, we apply judgment to determine whether promised deliverables are capable of being distinct and are distinct in the context of the contract. If these criteria are not met, the promised deliverables are accounted for as a combined performance obligation. For arrangements with multiple distinct performance obligations, we allocate consideration among the performance obligations based on their relative standalone selling price. Standalone selling price is the price at which we would sell a promised good or service separately to the customer. When not directly observable, we typically estimate standalone selling price by using the expected cost plus a margin approach. We typically establish a standalone selling price range for our deliverables, which is reassessed on a periodic basis or when facts and circumstances change. We assess the timing of the transfer of goods or services to the customer as compared to the timing of payments to determine whether a significant financing component exists. As a practical expedient, we do not assess the existence of a significant financing component when the difference between payment and transfer of deliverables is a year or less. If the difference in timing arises for reasons other than the provision of finance to either the customer or us, no financing component is deemed to exist. The primary purpose of our invoicing terms is to provide customers with simplified and predictable ways of purchasing our services, not to receive or provide financing from or to customers. We do not consider set up or transition fees paid upfront by our customers to represent a financing component, as such fees are required to encourage customer commitment to the project and protect us from early termination of the contract. Our contracts may be modified to add, remove or change existing performance obligations. The accounting for modifications to our contracts involves assessing whether the services added to an existing contract are distinct and whether the pricing is at the standalone selling price. Services added that are not distinct are accounted for on a cumulative catch up basis, while those that are distinct are accounted for prospectively, either as a separate contract if the additional services are priced at the standalone selling price, or as a termination of the existing contract and creation of a new contract if not priced at the standalone selling price. Services added to our application development and systems integration service contracts are typically not distinct, while services added to our other contracts, including application maintenance, testing and business process services contracts, are typically distinct. From time to time, we may enter into arrangements with third party suppliers to resell products or services. In such cases, we evaluate whether we are the principal (i.e., report revenues on a gross basis) or agent (i.e., report revenues on a net basis). In doing so, we first evaluate whether we control the good or service before it is transferred to the customer. If we control the good or service before it is transferred to the customer, we are the principal; if not, we are the agent. Determining whether we control the good or service before it is transferred to the customer may require judgment. Trade Accounts Receivable, Contract Assets and Contract Liabilities. We classify our right to consideration in exchange for deliverables as either a receivable or a contract asset. A receivable is a right to consideration that is unconditional (i.e., only the passage of time is required before payment is due). For example, we recognize a receivable for revenues related to our time and materials and transaction or volume-based contracts when earned regardless of whether amounts have been billed. We present such receivables in "Trade accounts receivable, net" in our consolidated statements of financial position at their net estimated realizable value. A contract asset is a right to consideration that is conditional upon factors other than the passage of time. Contract assets are presented in "Other current assets" in our consolidated statements of financial position and primarily relate to unbilled amounts on fixed-price contracts utilizing the cost to cost method of revenue recognition. Our contract liabilities, or deferred revenue, consist of advance payments from clients and billings in excess of revenues recognized. We classify deferred revenue as current or noncurrent based on the timing of when we expect to recognize the revenues. Our contract assets and contract liabilities are reported on a net basis by contract at the end of each reporting period. The difference between the opening and closing balances of our contract assets and contract liabilities primarily results from the timing difference between our performance obligations and the client’s payment. We receive payments from clients based on the terms established in our contracts, which vary by contract type. Allowance for Expected Credit Losses . We calculate expected credit losses for our trade accounts receivable and contract assets. Expected credit losses include losses expected based on known credit issues with specific customers as well as a general expected credit loss allowance based on relevant information about past events, including historical loss rates, current conditions, and reasonable economic forecasts that affect collectibility. We update our allowance for expected credit losses on a quarterly basis with changes in the allowance recognized in income from operations. Costs to Fulfill. Recurring operating costs for contracts with customers are recognized as incurred. Certain eligible, nonrecurring costs (i.e., set-up or transition costs) are capitalized when such costs (1) relate directly to the contract, (2) generate or enhance resources of the Company that will be used in satisfying the performance obligation in the future, and (3) are expected to be recovered. These costs are expensed ratably over the estimated life of the customer relationship, including expected contract renewals. In determining the estimated life of the customer relationship, we evaluate the average contract term, on a portfolio basis by nature of the services to be provided, and apply judgment in evaluating the rate of technological and industry change. Capitalized amounts are monitored regularly for impairment. Impairment losses are recorded when projected remaining undiscounted operating cash flows are not sufficient to recover the carrying amount of the capitalized costs to fulfill.
Accounts Receivable [Policy Text Block]	Trade Accounts Receivable, Contract Assets and Contract Liabilities. We classify our right to consideration in exchange for deliverables as either a receivable or a contract asset. A receivable is a right to consideration that is unconditional (i.e., only the passage of time is required before payment is due). For example, we recognize a receivable for revenues related to our time and materials and transaction or volume-based contracts when earned regardless of whether amounts have been billed. We present such receivables in "Trade accounts receivable, net" in our consolidated statements of financial position at their net estimated realizable value. A contract asset is a right to consideration that is conditional upon factors other than the passage of time. Contract assets are presented in "Other current assets" in our consolidated statements of financial position and primarily relate to unbilled amounts on fixed-price contracts utilizing the cost to cost method of revenue recognition. Our contract liabilities, or deferred revenue, consist of advance payments from clients and billings in excess of revenues recognized. We classify deferred revenue as current or noncurrent based on the timing of when we expect to recognize the revenues.
Stock-Based Compensation	Stock-Based Compensation. Stock-based compensation expense for awards of equity instruments to employees and non-employee directors is determined based on the grant date fair value of those awards. We recognize these compensation costs net of an estimated forfeiture rate over the requisite service period of the award. Forfeitures are estimated on the date of grant and revised if actual or expected forfeiture activity differs materially from original estimates. Stock-based compensation costs for PSUs that vest proportionally are recognized on a graded-vesting basis over the vesting period based on the most probable outcome of the performance conditions. If the minimum performance targets are not met, no compensation cost is recognized and any recognized compensation cost is reversed except for awards subject to a market condition. The fair value of RSUs and PSUs is determined based on the number of stock units granted and the quoted price of our stock at the date of grant. The fair value of PSUs granted subject to a market condition is determined using a Monte Carlo valuation model.
Foreign Currency	Foreign Currency. The assets and liabilities of our foreign subsidiaries whose functional currency is not the U.S. dollar are translated into U.S. dollars at current exchange rates while revenues and expenses are translated at average monthly exchange rates. The resulting translation adjustments are recorded in the caption "Accumulated other comprehensive income (loss)" on the consolidated statements of financial position. Foreign currency transactions and balances are those that are denominated in a currency other than the entity’s functional currency. An entity's functional currency is the currency of the primary economic environment in which it operates. The U.S. dollar is the functional currency for some of our foreign subsidiaries. For these subsidiaries, transactions and balances denominated in the local currency are foreign currency transactions. Foreign currency transactions and balances related to non-monetary assets and liabilities are remeasured to the functional currency of the entity at historical exchange rates while monetary assets and liabilities are remeasured to the functional currency of the entity at current exchange rates. Foreign currency exchange gains or losses from remeasurement are included in the caption "Foreign currency exchange gain (losses), net" on our consolidated statements of operations together with gains or losses on our undesignated foreign currency hedges.
Derivative Financial Instruments	Derivative Financial Instruments. Derivative financial instruments are recorded on our consolidated statements of financial position as either an asset or liability measured at its fair value as of the reporting date. Our derivative financial instruments consist primarily of foreign exchange forward and option contracts. For derivative financial instruments to qualify for hedge accounting, the following criteria must be met: (1) the hedging instrument must be designated as a hedge; (2) the hedged exposure must be specifically identifiable and must expose us to risk; and (3) it must be expected that a change in fair value of the hedging instrument and an opposite change in the fair value of the hedged exposure will have a high degree of correlation. Changes in our derivatives’ fair values are recognized in net income unless specific hedge accounting and documentation criteria are met (i.e., the instruments are designated and accounted for as hedges). We record the effective portion of the unrealized gains and losses on our derivative financial instruments that are designated as cash flow hedges in the caption "Accumulated other comprehensive income (loss)" in the consolidated statements of financial position. Any ineffectiveness or excluded portion of a designated cash flow hedge is recognized in net income. Upon occurrence of the hedged transaction, the gains and losses on the derivative are recognized in net income.
Use Of Estimates	The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying disclosures. The COVID-19 pandemic may affect management's estimates and assumptions of variable consideration in contracts with customers as well as other estimates and assumptions, in particular those that require a projection of our financial results, our cash flows or broader economic conditions, such as the annual effective tax rate, the allowance for doubtful accounts, the recoverability of capitalized deferred charges and the fair value of goodwill, long-lived assets and indefinite-lived intangible assets We evaluate our estimates on a continuous basis. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. The actual amounts may vary from the estimates used in the preparation of the accompanying consolidated financial statements.
Income Taxes	Income Taxes. We provide for income taxes utilizing the asset and liability method of accounting. Under this method, deferred income taxes are recorded to reflect the tax consequences in future years of differences between the tax basis of assets and liabilities and their financial reporting amounts at each balance sheet date, based on enacted tax laws and statutory tax rates applicable to the periods in which the differences are expected to affect taxable income. If it is determined that it is more likely than not that future tax benefits associated with a deferred income tax asset will not be realized, a valuation allowance is provided. The effect of a change in tax rates on deferred income tax assets and liabilities is recognized in the provision for income taxes in the period that includes the enactment date. Our provision for income taxes also includes the impact of provisions established for uncertain income tax positions, as well as any related penalties and interest. We adjust these reserves in light of changing facts and circumstances, such as the closing of a tax audit. To the extent that the final outcome of these matters differs from the amounts recorded, such differences will impact the provision for income taxes in the period in which such determination is made.
Earnings Per Share, Or EPS	Earnings Per Share. Basic EPS is computed by dividing earnings available to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted EPS includes all potential dilutive common stock in the weighted average shares outstanding. We exclude from the calculation of diluted EPS options with exercise prices that are greater than the average market price and shares related to stock-based awards whose combined exercise price and unamortized fair value were greater in each of those periods than the average market price of our common stock for the period, because their effect would be anti-dilutive. We excluded less than 1 million of anti-dilutive shares in each of 2020, 2019 and 2018 from our diluted EPS calculation. We include PSUs in the dilutive potential common shares when they become contingently issuable per the authoritative guidance and exclude them when they are not contingently issuable.
Recently Adopted/ New Accounting Pronouncements	Recently Adopted Accounting Pronouncements Date Issued and Topic Date Adopted and Method Description Impact May 2014 Revenue January 1, 2018 The new standard, as amended, sets forth a single comprehensive model for recognizing and reporting revenues. The standard also requires additional financial statement disclosures that enable users to understand the nature, amount, timing and uncertainty of revenues and cash flows relating to customer contracts. The standard allows for two methods of adoption: the full retrospective adoption, which requires the standard to be applied to each prior period presented, or the modified retrospective adoption, which requires the cumulative effect of adoption to be recognized as an adjustment to opening retained earnings in the period of adoption. As a result of the adoption, we recorded an adjustment to opening retained earnings of approximately $121 million. February 2016 Leases January 1, 2019 Effective Date Method The new standard replaces the existing guidance on leases and requires the lessee to recognize a ROU asset and a lease liability for all leases with lease terms greater than twelve months. For finance leases, the lessee recognizes interest expense and amortization of the ROU asset, and for operating leases, the lessee recognizes total lease expense on a straight-line basis. The standard offers several practical expedients for transition and certain expedients specific to lessees or lessors. The standard allows for two methods of adoption: retrospective to each prior reporting period presented with the cumulative effect of adoption recognized at the beginning of the earliest period presented or the effective date method, which is retrospective to the beginning of the period of adoption through a cumulative-effect adjustment. As a result of the adoption, we recorded an increase to total assets of $758 million, total liabilities of $756 million, and opening retained earnings of $2 million. June 2016 January 1, 2020 The new standard requires the measurement and recognition of expected credit losses using the current expected credit loss model for financial assets held at amortized cost, which includes the Company’s trade accounts receivable, certain financial instruments and contract assets. It replaces the existing incurred loss impairment model with an expected loss methodology. The recorded credit losses are adjusted each period for changes in expected lifetime credit losses. The standard requires a cumulative effect adjustment to the statement of financial position as of the beginning of the first reporting period in which the guidance is effective. As a result of the adoption, we recorded an increase to our opening retained earnings and "Trade accounts receivable, net" of $1 million each. Prior year amounts are not adjusted and continue to be reported in accordance with our historical accounting policies.
Cloud Computing Arrangements	Cloud Computing Arrangements. We capitalize certain implementation costs within prepaid assets that are incurred when implementing cloud computing service or SaaS arrangements, which primarily include efforts associated with configuration and development activities. Once the service is ready for use, capitalized costs are amortized over the term of the arrangement and recognized in income from operations.

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2020
Revenues [Abstract]
Disaggregation of Revenue	Disaggregation of Revenues The tables below present disaggregated revenues from contracts with clients by client location, service line and contract-type for each of our business segments. We believe this disaggregation best depicts how the nature, amount, timing and uncertainty of our revenues and cash flows are affected by industry, market and other economic factors. Our consulting and technology services include consulting, application development, systems integration, and application testing services as well as software solutions and related services while our outsourcing services include application maintenance, infrastructure and business process services. Revenues are attributed to geographic regions based upon client location. Substantially all of the revenue in our North America region relates to operations in the United States. Year Ended December 31, 2020 Financial Services Healthcare Products and Resources Communications, Media and Technology Total (in millions) Revenues Geography: North America $ 4,013 $ 4,181 $ 2,650 $ 1,737 $ 12,581 United Kingdom 463 157 371 344 1,335 Continental Europe 629 434 413 177 1,653 Europe - Total 1,092 591 784 521 2,988 Rest of World 516 80 262 225 1,083 Total $ 5,621 $ 4,852 $ 3,696 $ 2,483 $ 16,652 Service line: Consulting and technology services $ 3,691 $ 2,786 $ 2,249 $ 1,456 $ 10,182 Outsourcing services 1,930 2,066 1,447 1,027 6,470 Total $ 5,621 $ 4,852 $ 3,696 $ 2,483 $ 16,652 Type of contract: Time and materials $ 3,548 $ 1,950 $ 1,548 $ 1,515 $ 8,561 Fixed-price 1,736 1,777 1,741 871 6,125 Transaction or volume-based 337 1,125 407 97 1,966 Total $ 5,621 $ 4,852 $ 3,696 $ 2,483 $ 16,652 Year Ended December 31, 2019 Financial Services Healthcare Products and Resources Communications, Media and Technology Total (in millions) Revenues Geography: North America $ 4,137 $ 4,147 $ 2,678 $ 1,764 $ 12,726 United Kingdom 484 130 380 319 1,313 Continental Europe 728 341 453 169 1,691 Europe - Total 1,212 471 833 488 3,004 Rest of World 520 77 259 197 1,053 Total $ 5,869 $ 4,695 $ 3,770 $ 2,449 $ 16,783 Service line: Consulting and technology services $ 3,782 $ 2,564 $ 2,295 $ 1,305 $ 9,946 Outsourcing services 2,087 2,131 1,475 1,144 6,837 Total $ 5,869 $ 4,695 $ 3,770 $ 2,449 $ 16,783 Type of contract: Time and materials $ 3,651 $ 1,845 $ 1,632 $ 1,528 $ 8,656 Fixed-price 1,922 1,635 1,730 803 6,090 Transaction or volume-based 296 1,215 408 118 2,037 Total $ 5,869 $ 4,695 $ 3,770 $ 2,449 $ 16,783 Year Ended December 31, 2018 Financial Services Healthcare Products and Resources Communications, Media and Technology Total (in millions) Revenues Geography: North America $ 4,162 $ 4,254 $ 2,397 $ 1,480 $ 12,293 United Kingdom 481 91 358 344 1,274 Continental Europe 666 270 440 187 1,563 Europe - Total 1,147 361 798 531 2,837 Rest of World 536 53 220 186 995 Total $ 5,845 $ 4,668 $ 3,415 $ 2,197 $ 16,125 Service line: Consulting and technology services $ 3,571 $ 2,553 $ 2,024 $ 1,161 $ 9,309 Outsourcing services 2,274 2,115 1,391 1,036 6,816 Total $ 5,845 $ 4,668 $ 3,415 $ 2,197 $ 16,125 Type of contract: Time and materials $ 3,762 $ 1,836 $ 1,506 $ 1,366 $ 8,470 Fixed-price 1,859 1,852 1,521 734 5,966 Transaction or volume-based 224 980 388 97 1,689 Total $ 5,845 $ 4,668 $ 3,415 $ 2,197 $ 16,125
Capitalized Contract Cost	Costs to Fulfill The following table presents information related to the capitalized costs to fulfill, such as setup or transition activities . Costs to fulfill are recorded in "Other noncurrent assets" in our consolidated statements of financial position and the amortization expense of costs to fulfill is included in "Cost of revenues" in our consolidated statement of operations. Costs to obtain contracts were immaterial for the period disclosed. 2020 2019 (in millions) Beginning balance $ 485 $ 400 Costs capitalized 98 189 Amortization expense (102) (79) Impairment charge (14) (25) Ending balance $ 467 $ 485
Contract with Customer, Asset and Liability	The table below shows significant movements in contract assets: 2020 2019 (in millions) Beginning balance $ 334 $ 305 Revenues recognized during the period but not billed 289 313 Amounts reclassified to trade accounts receivable (308) (284) Ending balance $ 315 $ 334 Our contract liabilities, or deferred revenue, consist of advance payments and billings in excess of revenues recognized. The table below shows significant movements in the deferred revenue balances (current and noncurrent): 2020 2019 (in millions) Beginning balance $ 336 $ 348 Amounts billed but not recognized as revenues 368 319 Revenues recognized related to the opening balance of deferred revenue (285) (261) Other (1) — (70) Ending balance $ 419 $ 336
Reinsurance Recoverable, Allowance for Credit Loss	The following table presents the activity in the allowance for our trade accounts receivable: 2020 2019 (in millions) Beginning balance $ 67 $ 78 Impact of adoption of the Credit Loss Standard (1) — Provision for expected credit losses 8 (11) Write-offs charged against the allowance (17) — Ending balance $ 57 $ 67

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2020
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The allocations of preliminary purchase price to the fair value of the aggregate assets acquired and liabilities assumed were as follows: Collaborative Solutions New Signature Tin Roof 10th Magnitude Others Total Weighted Average Useful Life (dollars in millions) Cash $ 10 $ 13 $ — $ 2 $ 10 $ 35 Trade accounts receivable 38 13 10 7 21 89 Property and equipment and other assets 6 6 1 2 15 30 Operating lease assets, net 6 7 2 4 13 32 Non-deductible goodwill 44 292 — 90 66 492 Deductible goodwill 281 — 86 39 92 498 Customer relationship intangible assets 37 8 69 10 21 145 9.8 years Other intangible assets 8 1 — — 2 11 5.4 years Current liabilities (25) (20) (13) (15) (23) (96) Noncurrent liabilities (5) (8) (2) (5) (15) (35) Purchase price, inclusive of contingent consideration (1) $ 400 $ 312 $ 153 $ 134 $ 202 $ 1,201 (1) The purchase price for our acquisitions includes contingent consideration components with a collective maximum payout of $59 million, valued at $42 million at the date of acquisition, which is contingent upon achieving certain performance thresholds during the first two calendar years following the date of acquisition. The allocations of purchase price to the fair value of the aggregate assets acquired and liabilities assumed were as follows: Contino Meritsoft Zenith Others Total Weighted Average Useful Life (dollars in millions) Cash $ 7 $ 14 $ 9 $ 15 $ 45 Current assets 16 6 52 21 95 Property and equipment and other noncurrent assets 4 1 6 14 25 Non-deductible goodwill 198 147 76 21 442 Customer relationship intangible assets 29 46 73 19 167 10.7 years Other intangible assets 2 29 4 6 41 6.1 years Current liabilities (11) (3) (35) (22) (71) Noncurrent liabilities (10) (12) (17) (10) (49) Purchase price, inclusive of contingent consideration $ 235 $ 228 $ 168 $ 64 $ 695

Restructuring Charges (Tables)

Restructuring Charges (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring Charges [Abstract]
Restructuring Charges	Charges related to our realignment program and our 2020 Fit for Growth Plan were as follows: Years Ended December 31, 2020 2019 2018 (in millions) Realignment Program: Employee separation costs $ — $ 64 $ 18 Executive Transition Costs — 22 — Employee retention costs 15 45 — Professional fees 27 38 1 2020 Fit for Growth Plan: Employee separation costs 127 45 — Employee retention costs 5 2 — Facility exit costs and other charges (1) 41 1 — Total restructuring charges $ 215 $ 217 $ 19

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Marketable Securities [Table Text Block]	Our investments were as follows as of December 31: 2020 2019 (in millions) Short-term investments: Equity investment security $ 27 $ 26 Held-to-maturity investment securities 14 287 Time deposits (1) 3 466 Total short-term investments $ 44 $ 779 Long-term investments: Equity and cost method investments $ 35 $ 17 Time deposits (1) 405 — Total long-term investments $ 440 $ 17
Schedule of Realized Gain (Loss) [Table Text Block]	Proceeds from sales of available-for-sale investment securities and the gross gains and losses that have been included in earnings as a result of those sales were as follows: 2020 2019 2018 (in millions) Proceeds from sales of available-for-sale investment securities $ — $ 1,712 $ 1,285 Gross gains $ — $ 6 $ — Gross losses — (5) (4) Net realized gains (losses) on sales of available-for-sale investment securities $ — $ 1 $ (4)
Unrealized Gain (Loss) on Investments [Table Text Block]	The amortized cost and fair value of held-to-maturity investment securities were as follows as of December 31: 2020 2019 Amortized Fair Amortized Fair (in millions) Short-term investments, due within one year: Corporate and other debt securities $ 14 $ 14 $ 101 $ 101 Commercial paper — — 186 186 Total short-term held-to-maturity investments $ 14 $ 14 $ 287 $ 287

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment, Net [Abstract]
Schedule of property and equipment	Property and equipment were as follows as of December 31: Estimated Useful Life 2020 2019 (in years) (in millions) Buildings 30 $ 783 $ 790 Computer equipment 3 – 5 636 516 Computer software 3 – 8 840 820 Furniture and equipment 5 – 9 761 702 Land 7 11 Capital work-in-progress 122 133 Leasehold improvements Shorter of the lease term or 424 379 Sub-total 3,573 3,351 Accumulated depreciation and amortization (2,322) (2,042) Property and equipment, net $ 1,251 $ 1,309

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Lease's Statement of Financial Position	The following table provides information on the components of our operating and finance leases included in our consolidated statement of financial position as of December 31: Leases Location on Statement of Financial Position 2020 2019 Assets (in millions) ROU operating lease assets Operating lease assets, net $ 1,013 $ 926 ROU finance lease assets Property and equipment, net 14 16 Total $ 1,027 942 Liabilities Current Operating lease Operating lease liabilities $ 211 202 Finance lease Accrued expenses and other current liabilities 11 11 Noncurrent Operating lease Operating lease liabilities, noncurrent 846 745 Finance lease Other noncurrent liabilities 11 15 Total $ 1,079 $ 973
Schedule of Cash Flow and Other Information	The following table provides information on the weighted average remaining lease term and weighted average discount rate for our operating leases as of December 31: Operating Lease Term and Discount Rate 2020 2019 Weighted average remaining lease term 6.2 years 6.0 years Weighted average discount rate 5.7 % 6.0 % The following table provides supplemental cash flow information related to our operating leases as of December 31: 2020 2019 (in millions) Cash paid for amounts included in the measurement of operating lease liabilities $ 271 $ 232 ROU assets obtained in exchange for operating lease liabilities 273 274
Schedule of Future Minimum Payments	The following table provides the schedule of maturities of our operating lease liabilities and a reconciliation of the undiscounted cash flows to the operating lease liabilities recognized in the statement of financial position as of December 31: 2020 (in millions) 2021 $ 260 2022 218 2023 180 2024 143 2025 121 Thereafter 349 Total lease payments 1,271 Interest (214) Total lease liabilities $ 1,057

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, net (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Of Goodwill	Changes in goodwill by our reportable segments were as follows for the years ended December 31, 2020 and 2019: Segment January 1, 2020 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments December 31, 2020 (in millions) Financial Services $ 700 $ 204 $ 28 $ 932 Healthcare 2,595 149 11 2,755 Products and Resources 417 346 17 780 Communications, Media and Technology 267 289 8 564 Total goodwill $ 3,979 $ 988 $ 64 $ 5,031 Segment January 1, 2019 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments Other (1) December 31, 2019 (in millions) Financial Services $ 411 $ 288 $ (2) $ 3 $ 700 Healthcare 2,469 86 — 40 2,595 Products and Resources 384 18 1 14 417 Communications, Media and Technology 217 49 1 — 267 Total goodwill $ 3,481 $ 441 $ — $ 57 $ 3,979
Schedule of Finite-Lived Intangible Assets	Components of intangible assets were as follows as of December 31: 2020 2019 Gross Carrying Accumulated Net Carrying Gross Carrying Accumulated Net Carrying (in millions) Customer relationships $ 1,333 $ (490) $ 843 $ 1,181 $ (390) $ 791 Developed technology 388 (286) 102 388 (239) 149 Indefinite lived trademarks 72 — 72 72 — 72 Finite lived trademarks and other 80 (51) 29 71 (42) 29 Total intangible assets $ 1,873 $ (827) $ 1,046 $ 1,712 $ (671) $ 1,041
Schedule of Indefinite-Lived Intangible Assets	Components of intangible assets were as follows as of December 31: 2020 2019 Gross Carrying Accumulated Net Carrying Gross Carrying Accumulated Net Carrying (in millions) Customer relationships $ 1,333 $ (490) $ 843 $ 1,181 $ (390) $ 791 Developed technology 388 (286) 102 388 (239) 149 Indefinite lived trademarks 72 — 72 72 — 72 Finite lived trademarks and other 80 (51) 29 71 (42) 29 Total intangible assets $ 1,873 $ (827) $ 1,046 $ 1,712 $ (671) $ 1,041
Schedule Of Estimated Amortization Expense	The following table provides the estimated amortization expense related to our existing intangible assets for the next five years. Estimated Amortization (in millions) 2021 $ 159 2022 150 2023 107 2024 102 2025 99

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Accrued Expenses And Other Current Liabilities [Abstract]
Accrued Expenses And Other Current Liabilities	Accrued expenses and other current liabilities were as follows as of December 31: 2020 2019 (in millions) Compensation and benefits $ 1,607 $ 1,239 Customer volume and other incentives 266 251 Derivative financial instruments 1 8 Income taxes 34 152 Professional fees 143 137 Travel and entertainment 7 24 Other 461 380 Total accrued expenses and other current liabilities $ 2,519 $ 2,191

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of short-term debt	The following summarizes our short-term debt balances as of December 31: 2020 2019 Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate (in millions) (in millions) Term Loan - current maturities $ 38 1.0 % $ 38 2.6 %
Schedule of long-term debt	The following summarizes our long-term debt balances as of December 31: 2020 2019 (in millions) Term Loan $ 703 $ 741 Less: Current maturities (38) (38) Deferred financing costs (2) (3) Long-term debt, net of current maturities $ 663 $ 700
Schedule of debt maturities	The following represents the schedule of maturities of our term loan: Year Amounts (in millions) 2021 $ 38 2022 38 2023 627 $ 703

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule Of Income Before Provision For Income Tax	Income before provision for income taxes shown below is based on the geographic location to which such income was attributed for years ended December 31: 2020 2019 2018 (in millions) United States $ 814 $ 931 $ 947 Foreign 1,282 1,612 1,850 Income before provision for income taxes $ 2,096 $ 2,543 $ 2,797
Schedule Of Components Of Provision For Income Taxes	The provision for income taxes consisted of the following components for the years ended December 31: 2020 2019 2018 (in millions) Current: Federal and state $ 137 $ 549 $ 241 Foreign 383 400 449 Total current provision 520 949 690 Deferred: Federal and state (77) (320) 1 Foreign 261 14 7 Total deferred provision (benefit) 184 (306) 8 Total provision for income taxes $ 704 $ 643 $ 698
Reconciliation Between Effective Income Tax Rate and U.S. Federal Statutory Rate	The reconciliation between our effective income tax rate and the U.S. federal statutory rate were as follows for the years ended December 31: 2020 % 2019 % 2018 % (Dollars in millions) Tax expense, at U.S. federal statutory rate $ 440 21.0 $ 534 21.0 $ 587 21.0 State and local income taxes, net of federal benefit 52 2.5 59 2.3 56 2.0 Non-taxable income for Indian tax purposes (48) (2.3) (90) (3.5) (146) (5.2) Rate differential on foreign earnings 178 8.5 145 5.7 206 7.4 Net impact related to the implementation of the Tax Reform Act — — — — (5) (0.2) Net impact related to the India Tax Law — — 21 0.8 — — Recognition of previously unrecognized income tax benefits related to uncertain tax positions — — — — (12) (0.4) Credits and other incentives (51) (2.4) (57) (2.2) (19) (0.7) Reversal of indefinite reinvestment assertion 140 6.6 — — — — Other (7) (0.3) 31 1.2 31 1.1 Total provision for income taxes $ 704 33.6 $ 643 25.3 $ 698 25.0
Schedule Of Deferred Tax Assets and Liabilities	The significant components of deferred income tax assets and liabilities recorded on the consolidated statements of financial position were as follows as of December 31: 2020 2019 (in millions) Deferred income tax assets: Net operating losses $ 36 $ 27 Revenue recognition 41 39 Compensation and benefits 259 171 MAT and credit carryforwards 109 307 Expenses not currently deductible 147 352 592 896 Less: valuation allowance (29) (24) Deferred income tax assets, net 563 872 Deferred income tax liabilities: Depreciation and amortization 198 187 Deferred costs 105 110 Other 21 25 Deferred income tax liabilities 324 322 Net deferred income tax assets $ 239 $ 550
Summary Of Changes in Unrecognized Tax Benefits	Changes in unrecognized income tax benefits were as follows for the years ended December 31: 2020 2019 2018 (in millions) Balance, beginning of year $ 152 $ 117 $ 97 Additions based on tax positions related to the current year 28 22 8 Additions for tax positions of prior years 10 14 19 Additions for tax positions of acquired subsidiaries 3 — 6 Reductions for tax positions due to lapse of statutes of limitations — — (12) Reductions for tax positions of prior years — (1) — Settlements — — — Foreign currency exchange movement — — (1) Balance, end of year $ 193 $ 152 $ 117

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Location And Fair Values Of Derivative Financial Instruments In Our Condensed Consolidated Statements Of Financial Position	The following table provides information on the location and fair values of derivative financial instruments included in our consolidated statements of financial position as of December 31: 2020 2019 Designation of Derivatives Location on Statement of Assets Liabilities Assets Liabilities (in millions) Foreign exchange forward and option contracts – Designated as cash flow hedging instruments Other current assets $ 45 $ — $ 32 $ — Other noncurrent assets 26 — 8 — Accrued expenses and other current liabilities — — — 7 Other noncurrent liabilities — — — 2 Total 71 — 40 9 Foreign exchange forward contracts - Not designated as cash flow hedging instruments Other current assets 1 — 3 — Accrued expenses and other current liabilities — 1 — 1 Total 1 1 3 1 Total $ 72 $ 1 $ 43 $ 10
Notional Value Of Outstanding Cash Flow Hedge Contracts By Year Of Maturity And Net Unrealized (Loss) Gain Included In Accumulated Other Comprehensive Income (Loss)	The notional value of our outstanding contracts by year of maturity and the net unrealized gains and losses included in the caption "Accumulated other comprehensive income (loss)" in our consolidated statements of financial position, for such contracts were as follows as of December 31: 2020 2019 (in millions) 2020 $ — $ 1,505 2021 1,470 883 2022 803 — Total notional value of contracts outstanding (1) $ 2,273 $ 2,388 Net unrealized gains included in accumulated other comprehensive income (loss), net of taxes $ 55 $ 26
Location And Amounts Of Pre-Tax Gains (Losses) On Cash Flow Hedge Derivative Financial Instruments	The following table provides information on the location and amounts of pre-tax gains on our cash flow hedges for the year ended December 31: Change in Location of Net Derivative Net Gains Reclassified 2020 2019 2020 2019 (in millions) Foreign exchange forward and option contracts – Designated as cash flow hedging instruments $ 39 $ 39 Cost of revenues $ 3 $ 3 Selling, general and administrative expenses — 1 Total $ 3 $ 4
Additional Information Related To Outstanding Contracts Not Designated As Hedging Instruments	Additional information related to our outstanding foreign exchange forward contracts not designated as hedging instruments was as follows as of December 31: 2020 2019 Notional Fair Value Notional Fair Value (in millions) Contracts outstanding $ 637 $ — $ 702 $ 2 The following table provides information on the location and amounts of realized and unrealized pre-tax (losses) gains on our other derivative financial instruments for the year ended December 31: Location of Net (Losses) Gains Amount of Net (Losses) Gains 2020 2019 (in millions) Foreign exchange forward contracts - Not designated as hedging instruments Foreign currency exchange gains (losses), net $ (63) $ 8

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Financial Assets And (Liabilities) Measured At Fair Value On A Recurring Basis	The following table summarizes our financial assets and (liabilities) measured at fair value on a recurring basis as of December 31, 2020: Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 209 $ — $ — $ 209 Time deposits — 203 — 203 Commercial paper — 200 — 200 Short-term investments: Time deposits — 3 — 3 Equity investment security 27 — — 27 Other current assets Foreign exchange forward and option contracts — 46 — 46 Long-term investments: Time deposits (1) — 405 — 405 Other noncurrent assets Foreign exchange forward and option contracts — 26 — 26 Accrued expenses and other current liabilities: Foreign exchange forward contracts — (1) — (1) Contingent consideration liabilities — — (11) (11) Other noncurrent liabilities Contingent consideration liabilities — — (43) (43) (1) Balance represents restricted time deposits. See Note 11 . The following table summarizes our financial assets and (liabilities) measured at fair value on a recurring basis as of December 31, 2019: Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 1,646 $ — $ — $ 1,646 Short-term investments: Time deposits (1) — 466 — 466 Equity investment security 26 — — 26 Other current assets: Foreign exchange forward contracts — 35 — 35 Other noncurrent assets: Foreign exchange forward contracts — 8 — 8 Accrued expenses and other current liabilities: Foreign exchange forward contracts — (8) — (8) Contingent consideration liabilities — — (8) (8) Other noncurrent liabilities: Foreign exchange forward contracts — (2) — (2) Contingent consideration liabilities — — (30) (30) (1) Includes $414 million in restricted time deposits. See Note 11
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	The following table summarizes the changes in Level 3 contingent consideration liabilities: 2020 2019 (in millions) Beginning balance $ 38 $ 23 Initial measurement recognized at acquisition 42 33 Change in fair value recognized in SG&A expenses (23) (4) Payments (3) (14) Ending balance $ 54 $ 38

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Changes in "Accumulated other comprehensive income (loss)" by component were as follows for the year ended December 31, 2020: 2020 Before Tax Tax Net of Tax (in millions) Foreign currency translation adjustments: Beginning balance $ (63) $ (1) $ (64) Change in foreign currency translation adjustments 119 — 119 Ending balance $ 56 $ (1) $ 55 Unrealized gains on cash flow hedges: Beginning balance $ 31 $ (5) $ 26 Unrealized gains arising during the period 39 (8) 31 Reclassifications of net (gains) to: Cost of revenues (3) 1 (2) Net change 36 (7) 29 Ending balance $ 67 $ (12) $ 55 Accumulated other comprehensive income (loss): Beginning balance $ (32) $ (6) $ (38) Other comprehensive income (loss) 155 (7) 148 Ending balance $ 123 $ (13) $ 110 Changes in "Accumulated other comprehensive income (loss)" by component were as follows for the years ended December 31, 2019 and 2018: 2019 2018 Before Tax Tax Net of Tax Before Tax Tax Net of Tax (in millions) Foreign currency translation adjustments: Beginning balance $ (108) $ 5 $ (103) $ (38) $ — $ (38) Change in foreign currency translation adjustments 45 (6) 39 (70) 5 (65) Ending balance $ (63) $ (1) $ (64) $ (108) $ 5 $ (103) Unrealized (losses) on available-for-sale investment securities: Beginning balance $ (12) $ 4 $ (8) $ (11) $ 4 $ (7) Cumulative effect of change in accounting principle — — — — (1) (1) Net unrealized gains (losses) arising during the period 13 (4) 9 (5) 2 (3) Reclassification of net (gains) losses to Other, net (1) — (1) 4 (1) 3 Net change 12 (4) 8 (1) — (1) Ending balance $ — $ — $ — $ (12) $ 4 $ (8) Unrealized (loses) gains on cash flow hedges: Beginning balance $ (4) $ 1 $ (3) $ 154 $ (39) $ 115 Unrealized gains (losses) arising during the period 39 (7) 32 (87) 23 (64) Reclassifications of net gains to: Cost of revenues (3) 1 (2) (61) 15 (46) SG&A expenses (1) — (1) (10) 2 (8) Net change 35 (6) 29 (158) 40 (118) Ending balance $ 31 $ (5) $ 26 $ (4) $ 1 $ (3) Accumulated other comprehensive income (loss): Beginning balance $ (124) $ 10 $ (114) $ 105 $ (35) $ 70 Other comprehensive income (loss) 92 (16) 76 (229) 45 (184) Ending balance $ (32) $ (6) $ (38) $ (124) $ 10 $ (114)

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement, Noncash Expense [Abstract]
Schedule Of Allocation Of Total Stock-Based Compensation Expense	The allocation of total stock-based compensation expense between cost of revenues and selling, general and administrative expenses as well as the related income tax benefit were as follows for the three years ended December 31: 2020 2019 2018 (in millions) Cost of revenues $ 51 $ 54 $ 62 SG&A expenses 181 163 205 Total stock-based compensation expense $ 232 $ 217 $ 267 Income tax benefit $ 48 $ 39 $ 66
Summary Of The Activity For Restricted Stock Units	A summary of the activity for RSUs granted under our stock-based compensation plans as of December 31, 2020 and changes during the year then ended is presented below: Number of Weighted Average Unvested at January 1, 2020 4.5 $ 67.07 Granted 3.9 61.85 Vested (3.0) 65.42 Forfeited (1.0) 64.91 Unvested at December 31, 2020 4.4 $ 64.09
Summary Of The Activity For Performance Stock Units	The presentation reflects the number of PSUs at the maximum performance milestones. Number of Weighted Average Unvested at January 1, 2020 2.0 $ 69.73 Granted 1.9 62.00 Vested (0.2) 60.63 Forfeited (0.9) 67.59 Adjustment at the conclusion of the performance measurement period (1.1) 70.67 Unvested at December 31, 2020 1.7 $ 62.60
Schedule Of Assumptions Used To Calculate The Fair Value Of Option Grants	The fair values of the options granted under the Purchase Plan, were estimated at the date of grant during the years ended December 31, 2020, 2019, and 2018 based upon the following assumptions and were as follows: 2020 2019 2018 Dividend yield 1.1 % 1.3 % 1.0 % Weighted average volatility factor 35.9 % 24.9 % 21.0 % Weighted average risk-free interest rate 0.6 % 2.2 % 1.9 % Weighted average expected life (in years) 0.25 0.25 0.25 Weighted average grant date fair value $ 9.38 $ 9.82 $ 10.87

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Segment Operating Profit	Segment operating profits by reportable segment were as follows: 2020 2019 2018 (in millions) Financial Services $ 1,449 $ 1,605 $ 1,713 Healthcare 1,383 1,261 1,416 Products and Resources 1,078 1,028 1,023 Communications, Media and Technology 794 732 692 Total segment operating profit 4,704 4,626 4,844 Less: unallocated costs 2,590 2,173 2,043 Income from operations $ 2,114 $ 2,453 $ 2,801
Long-Lived Assets By Geographic Area	Long-lived assets by geographic area are as follows: 2020 2019 2018 (in millions) Long-lived Assets: (1) North America (2) $ 399 $ 445 $ 436 Europe 88 104 105 Rest of World (3) 764 760 853 Total $ 1,251 $ 1,309 $ 1,394 (1) Long-lived assets include property and equipment, net of accumulated depreciation and amortization. (2) Substantially all relates to the United States. (3) Substantially all relates to India.

Business Description and Summ_3

Business Description and Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Assets	$ 16,923	$ 16,204
Immaterial Adjustment [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Assets		$ 70
Share-based Payment Arrangement [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share - less than	1,000	1,000	1,000

Business Description and Summ_4

Business Description and Summary of Significant Accounting Policies Change in Accounting Policy of Correction of an Error (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liabilities	$ 6,087	$ 5,182
Retained earnings	10,689	11,022
Trade accounts receivable, net	3,087	3,256
Assets	$ 16,923	16,204
Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liabilities			$ 756
Assets			758
Cumulative Effect, Period of Adoption, Adjustment [Member] | Trade Accounts Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Trade accounts receivable, net		1
Cumulative Effect, Period of Adoption, Adjustment [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 1	$ 2	$ 121

Revenues (Details)

Revenues (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Revenues [Abstract]
Reduction in revenue due to proposed exit	$ 118
Reduction to additional expenses due to proposed exit	$ 33

Revenues Capitalized Costs to F

Revenues Capitalized Costs to Fulfill Contract with Customer (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues [Abstract]
Beginning Balance	$ 485	$ 400
Amortization expense	102	79
Costs Capitalized	98	189
Ending Balance	467	485
Capitalized Contract Cost, Impairment Loss	$ (14)	$ (25)

Revenues Significant Movements

Revenues Significant Movements in Contract Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues [Abstract]
Beginning Balance	$ 334	$ 305
Revenues recognized during the period but not billed	289	313
Amounts reclassified to accounts receivable	308	284
Ending Balance	$ 315	$ 334

Revenues Significant Movement_2

Revenues Significant Movements in Deferred Revenue Balances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues [Abstract]
Beginning Balane	$ 336	$ 348
Amounts billed but not recognized as revenues	368	319
Revenues recognized related to the opening balance of deferred revenue	285	261
Other	0	(70)
Ending Balance	$ 419	$ 336

Revenues Remaining Performance

Revenues Remaining Performance Obligations Narrative (Details) $ in Millions	Dec. 31, 2020USD ($)
Revenues [Abstract]
Revenue, Remaining Performance Obligation	$ 1,446
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Revenue, Remaining Performance Obligation, Percentage	75.00%

Revenues Disaggregation of Reve

Revenues Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 16,652	$ 16,783	$ 16,125
Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	8,561	8,656	8,470
Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	6,125	6,090	5,966
Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,966	2,037	1,689
North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	12,581	12,726	12,293
United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,335	1,313	1,274
Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,653	1,691	1,563
Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,988	3,004	2,837
Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,083	1,053	995
Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	10,182	9,946	9,309
Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	6,470	6,837	6,816
Financial Services
Disaggregation of Revenue [Line Items]
Revenues	5,621	5,869	5,845
Financial Services | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,548	3,651	3,762
Financial Services | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,736	1,922	1,859
Financial Services | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	337	296	224
Financial Services | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,013	4,137	4,162
Financial Services | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	463	484	481
Financial Services | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	629	728	666
Financial Services | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,092	1,212	1,147
Financial Services | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	516	520	536
Financial Services | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,691	3,782	3,571
Financial Services | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,930	2,087	2,274
Healthcare
Disaggregation of Revenue [Line Items]
Revenues	4,852	4,695	4,668
Healthcare | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,950	1,845	1,836
Healthcare | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,777	1,635	1,852
Healthcare | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,125	1,215	980
Healthcare | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,181	4,147	4,254
Healthcare | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	157	130	91
Healthcare | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	434	341	270
Healthcare | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	591	471	361
Healthcare | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	80	77	53
Healthcare | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,786	2,564	2,553
Healthcare | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,066	2,131	2,115
Products and Resources
Disaggregation of Revenue [Line Items]
Revenues	3,696	3,770	3,415
Products and Resources | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,548	1,632	1,506
Products and Resources | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,741	1,730	1,521
Products and Resources | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	407	408	388
Products and Resources | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,650	2,678	2,397
Products and Resources | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	371	380	358
Products and Resources | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	413	453	440
Products and Resources | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	784	833	798
Products and Resources | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	262	259	220
Products and Resources | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,249	2,295	2,024
Products and Resources | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,447	1,475	1,391
Communication, Media and Technology [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,483	2,449	2,197
Communication, Media and Technology [Member] | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,515	1,528	1,366
Communication, Media and Technology [Member] | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	871	803	734
Communication, Media and Technology [Member] | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	97	118	97
Communication, Media and Technology [Member] | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,737	1,764	1,480
Communication, Media and Technology [Member] | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	344	319	344
Communication, Media and Technology [Member] | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	177	169	187
Communication, Media and Technology [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	521	488	531
Communication, Media and Technology [Member] | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	225	197	186
Communication, Media and Technology [Member] | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,456	1,305	1,161
Communication, Media and Technology [Member] | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 1,027	$ 1,144	$ 1,036

Revenues Trade Accounts Receiva

Revenues Trade Accounts Receivable and Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Beginning Balance	$ 67	$ 78
Provision for expected credit losses	8	(11)
Write-offs charged against the allowance	(17)	0
Ending Balance	57	67
Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Beginning Balance	$ (1)
Ending Balance		$ (1)

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Business Combinations [Abstract]
Revenue from acquisitions	$ 222
Mustache [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Samlink [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Meritsoft
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Zenith
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Contino
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Code Zero [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Lev [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
EI-Technologies [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Collaborative Solutions [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
New Signature [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Tin Roof [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
10th Magnitude [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Bright Wolf [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Inawisdom [Member]
Business Combinations [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	100.00%

Business Combinations Allocatio

Business Combinations Allocation of Purchase Price (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Cash	$ 35	$ 45
Current assets		95
Property, plant and equipment and other noncurrent assets	30	25
Current liabilities	(96)	(71)
Noncurrent liabilities	(35)	(49)
Purchase price	1,201	695
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	89
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed. Operating Lease Right Of Use Asset	32
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill	492	442
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tax-Deductible Goodwill	498
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	59
Business Combination, Contingent Consideration, Liability	42
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	$ 145	$ 167
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years 9 months 18 days	10 years 8 months 12 days
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	$ 11	$ 41
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years 4 months 24 days	6 years 1 month 6 days
Collaborative Solutions [Member]
Business Acquisition [Line Items]
Cash	$ 10
Property, plant and equipment and other noncurrent assets	6
Current liabilities	(25)
Noncurrent liabilities	(5)
Purchase price	400
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	38
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed. Operating Lease Right Of Use Asset	6
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill	44
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tax-Deductible Goodwill	281
Collaborative Solutions [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	37
Collaborative Solutions [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	8
New Signature [Member]
Business Acquisition [Line Items]
Cash	13
Property, plant and equipment and other noncurrent assets	6
Current liabilities	(20)
Noncurrent liabilities	(8)
Purchase price	312
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	13
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed. Operating Lease Right Of Use Asset	7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill	292
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tax-Deductible Goodwill	0
New Signature [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	8
New Signature [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	1
Tin Roof [Member]
Business Acquisition [Line Items]
Cash	0
Property, plant and equipment and other noncurrent assets	1
Current liabilities	(13)
Noncurrent liabilities	(2)
Purchase price	153
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	10
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed. Operating Lease Right Of Use Asset	2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tax-Deductible Goodwill	86
Tin Roof [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	69
Tin Roof [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	0
10th Magnitude [Member]
Business Acquisition [Line Items]
Cash	2
Property, plant and equipment and other noncurrent assets	2
Current liabilities	(15)
Noncurrent liabilities	(5)
Purchase price	134
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	7
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed. Operating Lease Right Of Use Asset	4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill	90
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tax-Deductible Goodwill	39
10th Magnitude [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	10
10th Magnitude [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	0
Acquisitions
Business Acquisition [Line Items]
Cash	10	$ 15
Current assets		21
Property, plant and equipment and other noncurrent assets	15	14
Current liabilities	(23)	(22)
Noncurrent liabilities	(15)	(10)
Purchase price	202	64
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	21
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed. Operating Lease Right Of Use Asset	13
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill	66	21
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Tax-Deductible Goodwill	92
Acquisitions | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	21	19
Acquisitions | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	$ 2	6
Contino
Business Acquisition [Line Items]
Cash		7
Current assets		16
Property, plant and equipment and other noncurrent assets		4
Current liabilities		(11)
Noncurrent liabilities		(10)
Purchase price		235
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill		198
Contino | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired		29
Contino | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired		2
Meritsoft
Business Acquisition [Line Items]
Cash		14
Current assets		6
Property, plant and equipment and other noncurrent assets		1
Current liabilities		(3)
Noncurrent liabilities		(12)
Purchase price		228
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill		147
Meritsoft | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired		46
Meritsoft | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired		29
Zenith
Business Acquisition [Line Items]
Cash		9
Current assets		52
Property, plant and equipment and other noncurrent assets		6
Current liabilities		(35)
Noncurrent liabilities		(17)
Purchase price		168
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Deductible Goodwill		76
Zenith | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired		73
Zenith | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired		$ 4

Restructuring Charges (Details)

Restructuring Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Charges [Member]
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	$ 215	$ 217	$ 19
Employee separation costs
Restructuring Cost and Reserve [Line Items]
Balance - December 31, 2018	47	0
Employee separation costs accrued	127	109
Payments made	157	62
Balance - December 31, 2019	17	47	0
Realignment Program [Member] | Employee separation costs
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	0	64	18
Realignment Program [Member] | Executive Transition Costs
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	0	22	0
Realignment Program [Member] | Employee retention costs
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	15	45	0
Realignment Program [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	27	38	1
2020 Fit for Growth [Member] | Employee separation costs
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	127	45	0
2020 Fit for Growth [Member] | Employee retention costs
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	5	2	0
2020 Fit for Growth [Member] | Exit From Content Related Services [Member]
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	23	5
2020 Fit for Growth [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Employee separation costs accrued	41	$ 1	$ 0
Restructuring and Related Cost, Accelerated Depreciation	$ 7

Investments Short-term and Long

Investments Short-term and Long-term investments (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Marketable Securities [Line Items]
Short-term Investments	$ 44	$ 779
Restricted Investments		414
Long-term investments	440	17
Short-term Investments [Member]
Marketable Securities [Line Items]
Equity investment securities	27	26
Debt Securities, Held-to-maturity, Current	14	287
Debt Securities, Time Deposits	3	466
Restricted Investments		414
Long-term investments [Member]
Marketable Securities [Line Items]
Equity and Cost Method Investments	35	17
Restricted Investments	$ 405	$ 0

Investments Available-for-sale

Investments Available-for-sale securities - proceeds from sales, gross gains and losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Proceeds from Sale of Available-for-sale Securities	$ 0	$ 1,712	$ 1,285
Gross Gains	0	6	0
Gross Losses	0	(5)	(4)
Net realized (losses) gains on sales of available-for-sale investment securities	$ 0	$ 1	$ (4)

Investments Held-to-maturity se

Investments Held-to-maturity securities - amortized cost, gross unrealized gains and losses and fair value (Details) - Short-term Investments [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Current	$ 14	$ 287
Fair Value	14	287
Corporate And Other Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Current	14	101
Fair Value	14	101
Commercial Paper [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Current	0	186
Fair Value	$ 0	$ 186

Investments Held-to-maturity _2

Investments Held-to-maturity securities in a continuous unrealized loss position (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	$ 0
Maximum [Member]
Schedule of Held-to-maturity Securities [Line Items]
Total unrealized losses		$ (1)
Corporate And Other Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair value, less than 12 months		42
Commercial Paper [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair value, less than 12 months		70
Fair value, 12 months or more		$ 0

Investments Equity Method Inves

Investments Equity Method Investments (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Equity Method Investments	$ 9	$ 31
Equity Method Investment, Ownership Percentage		49.00%
Equity Method Investment, Impairment	57
Payments to Acquire Equity Method Investments		$ 26
Cost Method Investments	$ 8	$ 4

Property and Equipment, net (Na

Property and Equipment, net (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finance Lease, Right-of-Use, before Accumulated Amortization	$ 37	$ 30
Finance Lease, Right-of-Use Asset, Accumulated Amortization	23	14
Finance Lease, Right-of-Use Asset, Amortization	7	11
Capitalized Computer Software, Gross	159	129
Capitalized Computer Software, Accumulated Amortization	73	46
Capitalized Computer Software, Amortization	30	22	$ 14
Property, Plant and Equipment [Member]
Depreciation	$ 407	$ 363	$ 347

Property and Equipment, net (Sc

Property and Equipment, net (Schedule Of Property And Equipment, Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 3,573	$ 3,351
Accumulated depreciation and amortization	(2,322)	(2,042)
Property and equipment, net	1,251	1,309	$ 1,394
Finance Lease, Right-of-Use Asset, Accumulated Amortization	23	14
Finance Lease, Right-of-Use Asset, Amortization	7	11
Capitalized Computer Software, Amortization	$ 30	22	$ 14
Buildings [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	30 years
Property and Equipment, gross	$ 783	790
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 636	516
Computer Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Computer Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 840	820
Computer Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Computer Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	8 years
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 761	702
Furniture and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Furniture and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	9 years
Land [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 7	11
Capital Work-in-Progress [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	122	133
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 424	$ 379

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 302	$ 264
Variable lease cost	14	18
Short term lease rental expense	20	$ 16
Amount of operating leases not yet commenced	$ 92
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lease terms of leases not yet commenced	1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lease terms of leases not yet commenced	11 years

Leases Schedule of Leases State

Leases Schedule of Leases Statement of Financial Position (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease assets, net	$ 1,013	$ 926
ROU finance lease assets	14	16
Total leased assets	1,027	942
Current
Operating lease liabilities	211	202
Finance lease	11	11
Noncurrent
Operating lease liabilities, noncurrent	846	745
Finance lease	11	15
Total leased liabilities	1,079	973
Operating lease cost	302	264
Variable lease cost	$ 14	$ 18

Leases Schedule of Operating Le

Leases Schedule of Operating Lease Term and Discount Rate (Details)	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Weighted average remaining lease term	6 years 2 months 12 days	6 years
Weighted average discount rate	5.70%	6.00%

Leases Schedule of Cash Flow an

Leases Schedule of Cash Flow and Other Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 271	$ 232
ROU assets obtained in exchange for operating lease liabilities	$ 273	$ 274

Leases Schedule of Future minim

Leases Schedule of Future minimum Payments on Operating Leases (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2020	$ 260
2021	218
2022	180
2023	143
2024	121
Thereafter	349
Total lease payments	1,271
Interest	(214)
Total lease liabilities	$ 1,057

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, net (Schedule Of Goodwill Allocation By Reportable Segments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 3,979	$ 3,481
Additions	988	441
Foreign currency translation adjustments	64	0
Other		57
Goodwill, Ending Balance	5,031	3,979
Financial Services
Goodwill [Roll Forward]
Goodwill, Beginning Balance	700	411
Additions	204	288
Foreign currency translation adjustments	28	(2)
Other		3
Goodwill, Ending Balance	932	700
Healthcare
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,595	2,469
Additions	149	86
Foreign currency translation adjustments	11	0
Other		40
Goodwill, Ending Balance	2,755	2,595
Products and Resources
Goodwill [Roll Forward]
Goodwill, Beginning Balance	417	384
Additions	346	18
Foreign currency translation adjustments	17	1
Other		14
Goodwill, Ending Balance	780	417
Communications, Media and Technology
Goodwill [Roll Forward]
Goodwill, Beginning Balance	267	217
Additions	289	49
Foreign currency translation adjustments	8	1
Other		0
Goodwill, Ending Balance	$ 564	$ 267

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, net (Schedule Of Components For Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ (827)	$ (671)
Intangible Assets, Gross (Excluding Goodwill)	1,873	1,712
Intangible assets, net	1,046	1,041
Indefinite lived trademarks	72	72
Amortization of intangibles	152	162	$ 151
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,333	1,181
Accumulated amortization	(490)	(390)
Net carrying amount	843	791
Developed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	388	388
Accumulated amortization	(286)	(239)
Net carrying amount	102	149
Trademarks and other
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	80	71
Accumulated amortization	(51)	(42)
Net carrying amount	$ 29	$ 29

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets, net (Schedule Of Estimated Amortization Expense) (Details) $ in Millions	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 159
2021	150
2024	99
2022	107
2023	$ 102

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Accrued Expenses And Other Current Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accrued Expenses And Other Current Liabilities [Abstract]
Compensation and benefits	$ 1,607	$ 1,239
Customer volume and other incentives	266	251
Derivative financial instruments	1	8
Income taxes	34	152
Professional fees	143	137
Travel and entertainment	7	24
Other	461	380
Accrued expenses and other current liabilities	$ 2,519	$ 2,191

Debt (Details)

Debt (Details) $ in Millions, ₨ in Billions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2020INR (₨)	Nov. 30, 2018USD ($)
Credit Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Principal amount of debt			$ 750
Base Rate [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
Eurocurrency [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.875%
Minimum [Member] | Eurocurrency [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
Minimum [Member] | Eurocurrency Without Debt Ratings [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.875%
Maximum [Member]
Debt Instrument [Line Items]
Financial covenant, leverage ratio	3.50
Debt Instrument, Covenant Compliance, Leverage Ratio Following Material Acquisition(s)	3.75
Maximum [Member] | Eurocurrency [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
Maximum [Member] | Eurocurrency Without Debt Ratings [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
Revolving Credit Facility [Member] | Credit Agreement [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity			$ 1,750
Working Capital Facility [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity	$ 178	₨ 13

Debt (Short-Term Debt (Details)

Debt (Short-Term Debt (Details) - Credit Agreement [Member] - Term Loan [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Short-term Debt [Line Items]
Term Loan - Current Maturities	$ 38	$ 38
Weighted average interest rate	1.00%	2.60%

Debt (Long-Term Debt) (Details)

Debt (Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, net of current maturities	$ 663	$ 700
Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Net	(2)	(3)
Term Loan [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term debt	703	741
Less: Current portion	$ (38)	$ (38)

Debt (Debt Maturities) (Details

Debt (Debt Maturities) (Details) - Credit Agreement [Member] $ in Millions	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
2020	$ 38
2021	38
2022	$ 627

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) $ / shares in Units, $ in Millions	Oct. 28, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)$ / shares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2020INR (₨)	Apr. 30, 2018INR (₨)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Income Tax Expense (Benefit)			$ 704	$ 643	$ 698
Deferred income taxes related to MAT			$ 98	176
Incentive period for SEZs, years			15 years
Income tax holiday, increase in net income			$ 48	$ 90	$ 146
Increase in diluted EPS | $ / shares			$ 0.09	$ 0.16	$ 0.25
Accrued interest and penalties			$ 22	$ 16
Restricted Investments				414
Distribution from our India Subsidiary, Gross	$ 2,100
Distribution from our India Subsidiary, Net	2,000
Distribution from our India Subsidiary, Tax Withheld	$ 106
Tax on Accumulated Indian Earnings [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Income Tax Expense (Benefit)		$ 140
Ministry of Finance, India [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrepatriated foreign earnings				5,200
Internal Revenue Service (IRS) [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Net operating loss carryforward			98
Foreign Tax Authority [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Net operating loss carryforward			55
Foreign Tax Authority [Member] | Ministry of Finance, India [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Restricted Investments Initially Deposited			$ 384	393			₨ 28,000,000,000
One-time income tax expense				$ 21
Deposits Assets | ₨						₨ 5,000,000,000

Income Taxes (Schedule Of Incom

Income Taxes (Schedule Of Income Before Provision For Income Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States	$ 814	$ 931	$ 947
Foreign	1,282	1,612	1,850
Income before provision for income taxes	$ 2,096	$ 2,543	$ 2,797

Income Taxes ITD Dispute (Detai

Income Taxes ITD Dispute (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2020INR (₨)	Apr. 30, 2018INR (₨)
One-time Transaction [Table] [Line Items]
Income Tax Expense (Benefit)	$ 704	$ 643	$ 698
Restricted Investments		414
Long-term investments [Member]
One-time Transaction [Table] [Line Items]
Restricted Investments	$ 405	0
Short-term Investments [Member]
One-time Transaction [Table] [Line Items]
Restricted Investments		414
Foreign Tax Authority [Member] | Ministry of Finance, India [Member]
One-time Transaction [Table] [Line Items]
Deposits Assets | ₨						₨ 5,000,000,000
Deposits Assets, Percent Disputed Tax Amount	15.00%					15.00%
Restricted Investments Initially Deposited	$ 384	393					₨ 28,000,000,000
Foreign Tax Authority [Member] | Ministry of Finance, India [Member] | Other Noncurrent Assets [Member]
One-time Transaction [Table] [Line Items]
Deposits Assets	68
Foreign Tax Authority [Member] | Ministry of Finance, India [Member] | Other Current Assets [Member]
One-time Transaction [Table] [Line Items]
Deposits Assets		$ 70
Foreign Tax Authority [Member] | Ministry of Finance, India [Member] | 2016 India Cash Remittance [Member]
One-time Transaction [Table] [Line Items]
Foreign Earnings Repatriated				$ 2,800
Income Tax Expense (Benefit)				$ 135
Income Tax, Disputed Amount	$ 452					₨ 33,000,000,000
Foreign Tax Authority [Member] | Ministry of Finance, India [Member] | 2013 India Share Repurchase [Member]
One-time Transaction [Table] [Line Items]
Foreign Earnings Repatriated					$ 523

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components Of Provision For Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal and state	$ 137	$ 549	$ 241
Foreign	383	400	449
Total current provision	520	949	690
Deferred:
Federal and state	(77)	(320)	1
Foreign	261	14	7
Total deferred provision (benefit)	184	(306)	8
Total provision for income taxes	$ 704	$ 643	$ 698

Income Taxes (Reconciliation Be

Income Taxes (Reconciliation Between Effective Income Tax Rate And U.S. Federal Statutory Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Tax expense, at U.S. federal statutory rate, amount	$ 440	$ 534	$ 587
State and local income taxes, net of federal benefit, amount	52	59	56
Non-taxable income for Indian tax purposes, amount	(48)	(90)	(146)
Rate differential on foreign earnings, amount	178	145	206
Net impact related to the implementation of the Tax Reform Act	0	0	(5)
Net impact related to the India Tax Law	0	21	0
Recognition of previously unrecognized income tax benefits related to uncertain tax positions	0	0	(12)
Credits and other incentives, amount	(51)	(57)	(19)
Effective Income Tax Rate Reconciliation, Reversal of Indefinite Reinvestment Assertion, Amount	140	0	0
Other adjustments, amount	(7)	31	31
Total provision for income taxes	$ 704	$ 643	$ 698
Tax expense, at U.S. federal statutory rate, percentage	21.00%	21.00%	21.00%
State and local income taxes, net of federal benefit, percentage	2.50%	2.30%	2.00%
Non-taxable income for Indian tax purposes, percentage	(2.30%)	(3.50%)	(5.20%)
Rate differential on foreign earnings, percentage	8.50%	5.70%	7.40%
Net impact related to the Tax Reform Act, percentage	0	0	(0.002)
Net impact related to the India Tax Law, percentage	0.00%	0.80%	0.00%
Recognition of previously unrecognized income tax benefits related to uncertain tax positions, percentage	0.00%	0.00%	(0.40%)
Credits and other incentives, percent	(2.40%)	(2.20%)	(0.70%)
Effective Income Tax Rate Reconciliation, Reversal of Indefinite Reinvestment Assertion, Percent	6.60%	0.00%	0.00%
Other adjustments, percent	(0.30%)	1.20%	1.10%
Total provision for income taxes, percentage	33.60%	25.30%	25.00%

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets:
Net operating losses	$ 36	$ 27
Revenue recognition	41	39
Compensation and benefits	259	171
Minimum alternative tax (MAT) and other credits	109	307
Expenses not currently deductible	147	352
Deferred income tax assets, gross	592	896
Less valuation allowance	(29)	(24)
Deferred income tax assets, net	563	872
Deferred income tax liabilities:
Depreciation and amortization	198	187
Deferred Tax Liabilities, Deferred Expense	105	110
Other	21	25
Deferred income tax liabilities	324	322
Net deferred income tax assets	$ 239	$ 550

Income Taxes (Summary Of Change

Income Taxes (Summary Of Changes In Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Changes in unrecognized income tax benefits
Balance, beginning of year	$ 152	$ 117	$ 97
Additions based on tax positions related to the current year	28	22	8
Additions for tax positions of prior years	10	14	19
Unrecognized Tax Benefits, Increase Resulting from Acquisition	3	0	6
Reductions for tax positions due to lapse of statutes of limitations	0	0	(12)
Reductions for tax positions of prior years	0	(1)	0
Settlements	0	0	0
Foreign currency exchange movement	0	0	(1)
Balance, end of year	$ 193	$ 152	$ 117

Derivative Financial Instrume_3

Derivative Financial Instruments (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash flow hedge losses expected to be reclassified to earnings within the next 12 months	$ 35

Derivative Financial Instrume_4

Derivative Financial Instruments (Location And Fair Values Of Derivative Financial Instruments In Our Consolidated Statement Of Financial Position) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative assets fair value	$ 72	$ 43
Derivative liabilities fair value	1	10
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	1	3
Derivative liabilities fair value	1	1
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	1	3
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member] | Accrued Expenses And Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities fair value	1	1
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	71	40
Derivative liabilities fair value	0	9
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	45	32
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	26	8
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Accrued Expenses And Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities fair value	0	7
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities fair value	$ 0	$ 2

Derivative Financial Instrume_5

Derivative Financial Instruments (Notional Value Of Outstanding Cash Flow Hedge Contracts By Year Of Maturity And Net Unrealized (Loss) Gain Included In Accumulated Other Comprehensive Income) (Details) - Cash Flow Hedges [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Foreign Exchange Contract [Member]
Derivative [Line Items]
Net unrealized gains included in accumulated other comprehensive income (loss), net of taxes	$ 55	$ 26
Designated as Hedging Instrument [Member] | Foreign Exchange Contract, Maturity 2020 [Member]
Derivative [Line Items]
Derivative, notional amount	0	1,505
Designated as Hedging Instrument [Member] | Foreign Exchange Contract, Maturity 2021 [Member]
Derivative [Line Items]
Derivative, notional amount	1,470	883
Designated as Hedging Instrument [Member] | Foreign Exchange Contract, Maturity 2022 [Member]
Derivative [Line Items]
Derivative, notional amount	803	0
Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative, notional amount	2,273	$ 2,388
Designated as Hedging Instrument [Member] | Foreign Exchange Option [Member]
Derivative [Line Items]
Derivative, notional amount	$ 133

Derivative Financial Instrume_6

Derivative Financial Instruments (Location And Amounts Of Pre-Tax Gains (Losses) On Cash Flow Hedge Derivatives Financial Instruments) (Details) - Cash Flow Hedges [Member] - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 3	$ 4
Cost of revenues
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	3	3
SG&A expenses
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	1
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
(Increase) Decrease in Derivative Losses Recognized in Accumulated Other Comprehensive Income (Loss) (effective portion)	$ 39	$ 39

Derivative Financial Instrume_7

Derivative Financial Instruments (Additional Information Related To Outstanding Contracts Not Designated As Hedging Instruments) (Details) - Not Designated as Hedging Instrument [Member] - Foreign Exchange Forward Contracts [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative, notional amount	$ 637	$ 702
Market value	$ 0	$ 2

Derivative Financial Instrume_8

Derivative Financial Instruments (Location And Amounts Of Pre-Tax Gains (Losses) On Derivative Financial Instruments Not Designated As Hedges) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member] | Foreign Currency Gain (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of net gains (losses) on derivative instruments	$ (63)	$ 8

Fair Value Measurements (Financ

Fair Value Measurements (Financial Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Investments		$ 414
Business Combination, Contingent Consideration, Liability	$ (42)
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investment securities	27	26
Restricted Investments		414
Long-term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Investments	405	0
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investment securities	27
Fair Value, Recurring [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investment securities		26
Fair Value, Recurring [Member] | Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	46	35
Fair Value, Recurring [Member] | Accrued Expenses And Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	(11)	(8)
Foreign Currency Contracts, Liability, Fair Value Disclosure	(1)	(8)
Fair Value, Recurring [Member] | Other Noncurrent Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	26	8
Fair Value, Recurring [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	(43)	(30)
Foreign Currency Contracts, Liability, Fair Value Disclosure		(2)
Fair Value, Recurring [Member] | Long-term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Investments	405
Fair Value, Recurring [Member] | Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	209
Fair Value, Recurring [Member] | Money Market Funds [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		1,646
Fair Value, Recurring [Member] | Bank Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	203
Fair Value, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	200
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investment securities	27	26
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Accrued Expenses And Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	0	0
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Noncurrent Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	0	0
Foreign Currency Contracts, Liability, Fair Value Disclosure		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	209	1,646
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investment securities	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	46	35
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Accrued Expenses And Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	0	0
Foreign Currency Contracts, Liability, Fair Value Disclosure	(1)	(8)
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Noncurrent Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	26	8
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	0	0
Foreign Currency Contracts, Liability, Fair Value Disclosure		(2)
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Long-term investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Investments	405
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Bank Time Deposits [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	203
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	200
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investment securities	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Accrued Expenses And Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	(11)	(8)
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Noncurrent Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	0	0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	(43)	(30)
Foreign Currency Contracts, Liability, Fair Value Disclosure		0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		0
Bank Time Deposits [Member] | Fair Value, Recurring [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	3	466
Bank Time Deposits [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Bank Time Deposits [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	3	466
Bank Time Deposits [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	$ 0	$ 0

Fair Value Measurements (Level

Fair Value Measurements (Level 3 Contingent Consideration Liabilities) (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 38	$ 23
Initial measurement recognized at acquisition	42	33
Change in fair value recognized in SG&A expenses	(23)	(4)
Payments	(3)	(14)
Ending balance	$ 54	$ 38

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	$ 11,022	$ 11,424	$ 10,669
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	119	39	(65)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive income (loss)	148	76	(183)
AOCI, ending balance	10,836	11,022	11,424
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	0	8	0
Cumulative Effect, Period of Adoption, Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	1	2	121
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
AOCI, ending balance		1	2
Foreign currency translation adjustments:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	(63)	(108)	(38)
AOCI Tax, beginning balance	(1)	5	0
AOCI, beginning balance	(64)	(103)	(38)
Other Comprehensive Income (Loss), before Tax [Abstract]
Other Comprehensive Income (Loss), before Tax	119	45	(70)
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Tax	0	(6)	5
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive income (loss)		39	(65)
AOCI before Tax, ending balance	56	(63)	(108)
AOCI Tax, ending balance	(1)	(1)	5
AOCI, ending balance	55	(64)	(103)
Unrealized (losses) on available-for-sale investment securities:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	0	(12)	(11)
AOCI Tax, beginning balance	0	4	4
AOCI, beginning balance	0	(8)	(7)
Other Comprehensive Income (Loss), before Tax [Abstract]
OCI, before Reclassifications, before Tax		13	(5)
Reclassification from AOCI, Current Period, before Tax		(1)	4
Other Comprehensive Income (Loss), before Tax		12	(1)
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss) before Reclassifications, Tax		(4)	2
Reclassification from AOCI, Current Period, Tax		0	(1)
Other Comprehensive Income (Loss), Tax		(4)	0
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
OCI, before Reclassifications, Net of Tax		9	(3)
Reclassification from AOCI, Current Period, Net of Tax		(1)	3
Other comprehensive income (loss)		8	(1)
AOCI before Tax, ending balance		0	(12)
AOCI Tax, ending balance		0	4
AOCI, ending balance		0	(8)
Unrealized gains on cash flow hedges:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	31	(4)	154
AOCI Tax, beginning balance	(5)	1	(39)
AOCI, beginning balance	26	(3)	115
Other Comprehensive Income (Loss), before Tax [Abstract]
OCI, before Reclassifications, before Tax	39	39	(87)
Other Comprehensive Income (Loss), before Tax	36	35	(158)
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss) before Reclassifications, Tax	(8)	(7)	23
Other Comprehensive Income (Loss), Tax	(7)	(6)	40
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
OCI, before Reclassifications, Net of Tax	31	32	(64)
Other comprehensive income (loss)	29	29	(118)
AOCI before Tax, ending balance	67	31	(4)
AOCI Tax, ending balance	(12)	(5)	1
AOCI, ending balance	55	26	(3)
Accumulated other comprehensive income (loss):
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	(32)	(124)	105
AOCI Tax, beginning balance	(6)	10	(35)
AOCI, beginning balance	(38)	(114)	70
Other Comprehensive Income (Loss), before Tax [Abstract]
Other Comprehensive Income (Loss), before Tax	155	92	(229)
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Tax	(7)	(16)	45
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive income (loss)	148	76	(184)
AOCI before Tax, ending balance	123	(32)	(124)
AOCI Tax, ending balance	(13)	(6)	10
AOCI, ending balance	110	(38)	(114)
Accumulated other comprehensive income (loss): | Cumulative Effect, Period of Adoption, Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance		(1)	(1)
Other Comprehensive Income (Loss), Tax [Abstract]
Cumulative effect of change in accounting principle , Tax			(1)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
AOCI, ending balance			(1)
Cost of revenues | Unrealized gains on cash flow hedges:
Other Comprehensive Income (Loss), before Tax [Abstract]
Reclassification from AOCI, Current Period, before Tax	(3)	(3)	(61)
Other Comprehensive Income (Loss), Tax [Abstract]
Reclassification from AOCI, Current Period, Tax	1	1	15
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Reclassification from AOCI, Current Period, Net of Tax	$ (2)	(2)	(46)
SG&A expenses | Unrealized gains on cash flow hedges:
Other Comprehensive Income (Loss), before Tax [Abstract]
Reclassification from AOCI, Current Period, before Tax		(1)	(10)
Other Comprehensive Income (Loss), Tax [Abstract]
Reclassification from AOCI, Current Period, Tax		0	2
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Reclassification from AOCI, Current Period, Net of Tax		$ (1)	$ (8)

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	Oct. 27, 2020	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Other Commitments [Line Items]
Accrued expenses and other current liabilities		$ 2,519	$ 2,191
Insurance Receivable		$ 7	$ 20
Syntel Sterling Best Shores Mauritius Ltd. [Member]
Other Commitments [Line Items]
Litigation Settlement, Amount Awarded from Other Party	$ 854
Litigation Settlement Amount Awarded From Other Party, Punitive Damages	$ 570
India Defined Contribution Obligation [Member]
Other Commitments [Line Items]
Accrued expenses and other current liabilities				$ 117

Employee Benefits (Narrative) (

Employee Benefits (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Accrued expenses and other current liabilities	$ 2,519	$ 2,191
Gratuity Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Liability, Defined Benefit Plan	124	135
Fund assets	186	160
Pension and Other Postretirement Benefits Cost (Reversal of Cost)	35	38	$ 53
India Defined Contribution Obligation [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued expenses and other current liabilities				$ 117
United States and Europe
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	118	117	108
India
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	$ 98	$ 101	$ 88
Employee contribution percentage, maximum	12.00%

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
2017 Incentive Plan [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares authorized			48.8
Shares available for grant	28.8
Restricted Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized stock-based compensation expense	$ 247
Weighted average remaining requisite service period	1 year 9 months 18 days
Weighted Average Grant Date Fair Value, Granted	$ 61.85	$ 64.12	$ 74.94
Performance Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized stock-based compensation expense	$ 34
Weighted average remaining requisite service period	2 years
Weighted Average Grant Date Fair Value, Granted	$ 62	$ 70.77	$ 81.98
Employee Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares authorized			40
Shares available for grant	5.9
Vesting period	3 months
Eligible employees purchase percentage of whole share of fair market value	90.00%
Shares issued	3
Fair value of shares issued	$ 28
Minimum [Member] | Restricted Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period	1 year
Minimum [Member] | Performance Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period	1 year
Maximum [Member] | Restricted Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period	4 years
Maximum [Member] | Performance Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period	4 years

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans (Schedule Of Allocation Of Total Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense		$ 217	$ 267
Share-based Payment Arrangement, Noncash Expense	$ 232	217	267
Income tax benefit	48	39	66
Cost of revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	51	54	62
SG&A expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 181	$ 163	$ 205

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans (Schedule Of Assumptions Used To Calculate The Fair Value Of Option Grants) (Details) - Employee Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Dividend yield	1.10%	1.30%	1.00%
Weighted average volatility factor	35.90%	24.90%	21.00%
Weighted average expected life (in years)	3 months	3 months	3 months
Weighted average risk-free interest rate	0.60%	2.20%	1.90%
Weighted average grant date fair value	$ 9.38	$ 9.82	$ 10.87

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans (Summary Of The Activity For Performance Stock Units) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Performance Stock Units [Member]
Number of Units
Number of Units, Unvested at beginning of period	2
Number of Units, Granted	1.9
Number of Units, Vested	(0.2)
Number of Units, Forfeited	(0.9)
Number of Units, Adjustment at the conclusion of the performance measurement period	1.1
Number of Units, Unvested at end of period	1.7	2
Weighted Average Grant Date Fair Value (in dollars)
Weighted Average Grant Date Fair Value, Unvested at beginning of period	$ 69.73
Weighted Average Grant Date Fair Value, Granted	62	$ 70.77	$ 81.98
Weighted Average Grant Date Fair Value, Vested	60.63
Weighted Average Grant Date Fair Value, Forfeited	67.59
Weighted Average Grant Date Fair Value, Reduction due to the achievement of lower than maximum performance milestones	70.67
Weighted Average Grant Date Fair Value, Unvested at end of period	$ 62.60	$ 69.73
Unrecognized stock-based compensation expense	$ 34
Weighted average remaining requisite service period	2 years
Restricted Stock Units [Member]
Number of Units
Number of Units, Unvested at beginning of period	4.5
Number of Units, Granted	3.9
Number of Units, Vested	(3)
Number of Units, Forfeited	(1)
Number of Units, Unvested at end of period	4.4	4.5
Weighted Average Grant Date Fair Value (in dollars)
Weighted Average Grant Date Fair Value, Unvested at beginning of period	$ 67.07
Weighted Average Grant Date Fair Value, Granted	61.85	$ 64.12	$ 74.94
Weighted Average Grant Date Fair Value, Vested	65.42
Weighted Average Grant Date Fair Value, Forfeited	64.91
Weighted Average Grant Date Fair Value, Unvested at end of period	$ 64.09	$ 67.07
Unrecognized stock-based compensation expense	$ 247
Weighted average remaining requisite service period	1 year 9 months 18 days

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans (Summary Of The Activity For Restricted Stock Units) (Details) - Restricted Stock Units [Member] - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Units
Number of Units, Unvested at beginning of period	4.5
Number of Units, Granted	3.9
Number of Units, Vested	(3)
Number of Units, Forfeited	(1)
Number of Units, Unvested at end of period	4.4	4.5
Weighted Average Grant Date Fair Value (in dollars)
Weighted Average Grant Date Fair Value, Unvested at beginning of period	$ 67.07
Weighted Average Grant Date Fair Value, Granted	61.85	$ 64.12	$ 74.94
Weighted Average Grant Date Fair Value, Vested	65.42
Weighted Average Grant Date Fair Value, Forfeited	64.91
Weighted Average Grant Date Fair Value, Unvested at end of period	$ 64.09	$ 67.07

Related Party Transactions (Det

Related Party Transactions (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Cognizant U.S. Foundation
Related Party Transaction [Line Items]
Related Party Transaction, Amounts of Transaction	$ 100

Segment Information (Revenues F

Segment Information (Revenues From External Customers And Segment Operating Profit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Income from operations	$ 2,114	$ 2,453	$ 2,801
Operating Segments [Member]
Segment Reporting Information [Line Items]
Income from operations	4,704	4,626	4,844
Operating Segments [Member] | Financial Services
Segment Reporting Information [Line Items]
Income from operations	1,449	1,605	1,713
Operating Segments [Member] | Healthcare
Segment Reporting Information [Line Items]
Income from operations	1,383	1,261	1,416
Operating Segments [Member] | Products and Resources
Segment Reporting Information [Line Items]
Income from operations	1,078	1,028	1,023
Operating Segments [Member] | Communications, Media and Technology
Segment Reporting Information [Line Items]
Income from operations	794	732	692
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Less: unallocated costs	$ 2,590	$ 2,173	$ 2,043

Segment Information (Revenues A

Segment Information (Revenues And Long-Lived Assets By Geographic Area) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Geographic Areas, Long-Lived Assets
Long-lived assets	$ 1,251	$ 1,309	$ 1,394
North America [Member]
Geographic Areas, Long-Lived Assets
Long-lived assets	399	445	436
Europe [Member]
Geographic Areas, Long-Lived Assets
Long-lived assets	88	104	105
Rest of World [Member]
Geographic Areas, Long-Lived Assets
Long-lived assets	$ 764	$ 760	$ 853

Valuation And Qualifying Acco_2

Valuation And Qualifying Accounts (Valuation And Qualifying Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Warranty Accrual [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 33	$ 32	$ 30
Charged to Costs and Expenses	32	33	32
Charged to Other Accounts	0	0	0
Deductions/Other	33	32	30
Balance at End of Period	32	33	32
Valuation Allowance - Deferred Income Tax Assets [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	24	11	10
Charged to Costs and Expenses	5	15	1
Charged to Other Accounts	0	0	0
Deductions/Other	0	2	0
Balance at End of Period	$ 29	$ 24	$ 11

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event [Member] - USD ($) $ / shares in Units, $ in Millions	Feb. 03, 2021	Feb. 28, 2021	Jan. 31, 2021
Subsequent Event [Line Items]
Dividends declared per common share	$ 0.24
Magenic [Member]
Subsequent Event [Line Items]
Payments to Acquire Businesses, Gross		$ 240
Servian [Member]
Subsequent Event [Line Items]
Payments to Acquire Businesses, Gross			$ 240
Linium [Member]
Subsequent Event [Line Items]
Payments to Acquire Businesses, Gross			$ 85