Cognizant Technology Solutions (CTSH) 10-K 19 Feb 19 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2018	Feb. 08, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	CTSH
Entity Registrant Name	COGNIZANT TECHNOLOGY SOLUTIONS CORP
Entity Central Index Key	1,058,290
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		575,099,275
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 45.7
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No

Consolidated Statements Of Fina

Consolidated Statements Of Financial Position - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 1,161	$ 1,925
Short-term investments	3,350	3,131
Trade accounts receivable, net of allowances of $78 and $65, respectively	3,257	2,865
Unbilled accounts receivable	0	357
Other current assets	909	833
Total current assets	8,677	9,111
Property and equipment, net	1,394	1,324
Goodwill	3,481	2,704
Intangible assets, net	1,150	981
Deferred income tax assets, net	442	418
Long-term investments	80	235
Other noncurrent assets	689	448
Total assets	15,913	15,221
Liabilities and Stockholders' Equity
Accounts payable	215	210
Deferred revenue	286	383
Short-term debt	9	175
Accrued expenses and other current liabilities	2,267	2,071
Total current liabilities	2,777	2,839
Deferred revenue, noncurrent	62	104
Deferred income tax liabilities, net	183	146
Long-term debt	736	698
Long-term income taxes payable	478	584
Other noncurrent liabilities	253	181
Total liabilities	4,489	4,552
Commitments and contingencies (See Note 15)
Stockholders' Equity:
Preferred stock, $0.10 par value, 15.0 shares authorized, none issued	0	0
Class A common stock, $0.01 par value, 1,000 shares authorized, 577 and 588 shares issued and outstanding at December 31, 2018 and 2017, respectively	6	6
Additional paid-in capital	47	49
Retained earnings	11,485	10,544
Accumulated other comprehensive income (loss)	(114)	70
Total stockholders’ equity	11,424	10,669
Total liabilities and stockholders’ equity	$ 15,913	$ 15,221

Consolidated Statements Of Fi_2

Consolidated Statements Of Financial Position (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Trade accounts receivable, allowances	$ 78	$ 65
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	577,000,000	588,000,000
Class A common stock, shares outstanding	577,000,000	588,000,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenues	$ 16,125	$ 14,810	$ 13,487
Operating expenses:
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)	9,838	9,152	8,108
Selling, general and administrative expenses	3,026	2,769	2,731
Depreciation and amortization expense	460	408	359
Income from operations	2,801	2,481	2,289
Other income (expense), net:
Interest income	177	133	115
Interest expense	(27)	(23)	(19)
Foreign currency exchange gains (losses), net	(152)	67	(30)
Other, net	(2)	(3)	2
Total other income (expense), net	(4)	174	68
Income before provision for income taxes	2,797	2,655	2,357
Provision for income taxes	(698)	(1,153)	(805)
Income from equity method investments	2	2	1
Net income	$ 2,101	$ 1,504	$ 1,553
Basic earnings per share	$ 3.61	$ 2.54	$ 2.56
Diluted earnings per share	$ 3.60	$ 2.53	$ 2.55
Weighted average number of common shares outstanding—Basic	582	593	607
Dilutive effect of shares issuable under stock-based compensation plans	2	2	3
Weighted average number of common shares outstanding—Diluted	584	595	610

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 2,101	$ 1,504	$ 1,553
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(65)	111	(59)
Change in unrealized gains and losses on cash flow hedges	(118)	76	51
Change in unrealized losses on available-for-sale investment securities	0	(3)	0
Other comprehensive income (loss)	(183)	184	(8)
Comprehensive income	$ 1,918	$ 1,688	$ 1,545

Consolidated Statements Of Stoc

Consolidated Statements Of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated other comprehensive income (loss):
AOCI, beginning balance at Dec. 31, 2015	$ 9,278	$ 6	$ 453	$ 8,925	$ (106)
Beginning balance, shares at Dec. 31, 2015		609
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,553			1,553
Other comprehensive income (loss)	(8)				(8)
Common stock issued, stock-based compensation plans	176		176
Common stock issued, stock based compensation plans and other, shares		8
Tax benefit, stock-based compensation plans	24		24
Stock-based compensation expense	217		217
Repurchases of common stock	(512)		(512)
Repurchases of common stock, shares		(9)
AOCI, ending balance at Dec. 31, 2016	10,728	$ 6	358	10,478	(114)
Ending balance, shares at Dec. 31, 2016		608
AOCI, beginning balance at Dec. 31, 2015	9,278	$ 6	453	8,925	(106)
Beginning balance, shares at Dec. 31, 2015		609
AOCI, ending balance at Dec. 31, 2018	$ 11,424	$ 6	47	11,485	(114)
Ending balance, shares at Dec. 31, 2018	577	577
AOCI, beginning balance at Dec. 31, 2016	$ 10,728	$ 6	358	10,478	(114)
Beginning balance, shares at Dec. 31, 2016		608
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,504			1,504
Other comprehensive income (loss)	184				184
Common stock issued, stock-based compensation plans	189		189
Common stock issued, stock based compensation plans and other, shares		9
Stock-based compensation expense	221		221
Repurchases of common stock	(1,889)		(719)	(1,170)
Repurchases of common stock, shares		(29)
Dividends declared	(268)			(268)
AOCI, ending balance at Dec. 31, 2017	$ 10,669	$ 6	49	10,544	70
Ending balance, shares at Dec. 31, 2017	588	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	$ 6	$ 47	11,485	(114)
Ending balance, shares at Dec. 31, 2018	577	577
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 121			$ 122	$ (1)

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 2,101	$ 1,504	$ 1,553
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	498	443	379
Provision for doubtful accounts	13	15	12
Deferred income taxes	8	124	(91)
Stock-based compensation expense	267	221	217
Other	112	(86)	46
Changes in assets and liabilities:
Trade accounts receivable	(365)	(249)	(330)
Other current assets	216	(181)	(104)
Other noncurrent assets	(224)	(89)	(59)
Accounts payable	(4)	16	6
Deferred revenue, current and noncurrent	(86)	18	(38)
Other current and noncurrent liabilities	56	671	54
Net cash provided by operating activities	2,592	2,407	1,645
Cash flows from investing activities:
Purchases of property and equipment	(377)	(284)	(300)
Purchases of available-for-sale investment securities	(1,630)	(3,120)	(4,231)
Proceeds from maturity or sale of available-for-sale investment securities	1,838	3,404	3,982
Purchases of held-to-maturity investment securities	(1,363)	(1,221)	(54)
Proceeds from maturity of held-to-maturity investment securities	1,164	404	15
Purchases of other investments	(513)	(385)	(884)
Proceeds from maturity or sale of other investments	365	836	843
Payments for business combinations, net of cash acquired, and equity and cost method investments	(1,111)	(216)	(334)
Net cash (used in) investing activities	(1,627)	(582)	(963)
Cash flows from financing activities:
Issuance of common stock under stock-based compensation plans	181	189	176
Repurchases of common stock	(1,261)	(1,889)	(512)
Repayment of term loan borrowings and capital lease obligations	(91)	(95)	(57)
Net change in notes outstanding under the revolving credit facility	(75)	75	(350)
Proceeds from debt modification	25	0	0
Debt issuance costs	(4)	0	0
Dividends paid	(468)	(265)	0
Net cash (used in) financing activities	(1,693)	(1,985)	(743)
Effect of exchange rate changes on cash and cash equivalents	(36)	51	(30)
(Decrease) in cash and cash equivalents	(764)	(109)	(91)
Cash and cash equivalents, beginning of year	1,925	2,034	2,125
Cash and cash equivalents, end of period	1,161	1,925	2,034
Supplemental information:
Cash paid for income taxes during the year	597	587	845
Cash interest paid during the year	$ 21	$ 21	$ 16

Business Description and Summar

Business Description and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
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, transforming clients’ business, operating and technology models for the digital era. Our industry-based, consultative approach helps customers envision, build and run more innovative and efficient businesses. Our services include digital services and solutions, consulting, application development, systems integration, application testing, application maintenance, infrastructure services and business process services. Digital services are becoming an increasingly important part of our portfolio of services and solutions and are often integrated or delivered along with our other services. We tailor our services and solutions to specific industries and use an integrated global delivery model that employs customer service teams based at customer locations and delivery teams located at customer 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 generally accepted accounting principles in the United States of America ("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. 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 and 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. We have classified and accounted for our marketable debt securities as either available-for-sale or held-to-maturity. After consideration of our risk versus reward objectives, as well as our liquidity requirements, we may sell our available-for-sale securities prior to their stated maturities. We classify these marketable securities with maturities at the date of purchase beyond 90 days as short-term investments based on their highly liquid nature and because such marketable securities represent an investment of cash that is available for current operations. 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. Available-for-sale securities are reported at fair value with changes in unrealized gains and losses recorded as a separate component of accumulated other comprehensive income (loss) until realized. We determine the cost of the securities sold based on the specific identification method. Held-to-maturity securities are reported at amortized cost. Time deposits with financial institutions are valued at cost, which approximates fair value. Interest and amortization of premiums and discounts for debt securities are included in interest income. On a quarterly basis, we evaluate our available-for-sale and held-to-maturity investments for possible other-than-temporary impairment by reviewing quantitative and qualitative factors. If we do not intend to sell the security or it is not more likely than not that we will be required to sell the security before recovery of our amortized cost, we evaluate quantitative and qualitative criteria to determine whether we expect to recover the amortized cost basis of the security. If we do not expect to recover the entire amortized cost basis of the security, we consider the security to be other-than-temporarily impaired and we record the difference between the security’s amortized cost basis and its recoverable amount in earnings and the difference between the security’s recoverable amount and fair value in other comprehensive income. If we intend to sell the security or it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis, the security is also considered other-than-temporarily impaired and we recognize the entire difference between the security’s amortized cost basis and its fair value in earnings. Short-term Financial Assets and Liabilities. Cash and certain cash equivalents, 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 improvement. In India, leasehold land is leased by us from the government of India with lease terms ranging up to 99 years. Lease payments are made at the inception of the lease agreement and amortized over the lease term. Maintenance and repairs are expensed as incurred, while renewals and betterments are capitalized. Deposits paid towards acquisition of long-lived assets and the cost of assets not put in use before the balance sheet date are disclosed under the caption "Capital work-in-progress" in Note 7 . 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. We capitalize costs incurred after technological feasibility is reached but before software is available for general release to customers, 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 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 . 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 carrying value. The Company's proportionate share of the net income or loss of the investee is recorded in the caption "Income from equity method investments" on our consolidated statements of operations. The investment balance is increased or decreased for cash contributions or distributions to or from these investees. Long-lived Assets and Finite-lived Intangible Assets. We review long-lived assets and certain finite-lived identifiable intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. We recognize an impairment loss when the sum of undiscounted expected future cash flows is less than the carrying amount of such assets. The impairment loss is determined as the amount by which the carrying amount of the asset exceeds the fair value of the asset. 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 trading plan adopted pursuant to Rule 10b5-1 of the Exchange Act, or in private transactions, including through accelerated stock repurchase agreements ("ASRs") entered into with financial institutions, in accordance with applicable 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 customers 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 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. 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 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 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. Prior to the adoption of ASC 606 on January 1, 2018, revenues were earned and recognized when all of the following criteria were met: evidence of an arrangement existed, the price was fixed or determinable, the services had been rendered and collectability was reasonably assured. Contingent or incentive revenues were recognized when the contingency was satisfied and we concluded the amounts were earned. Volume discounts were recorded as a reduction of revenues as services were provided. Revenues also included the reimbursement of out-of-pocket expenses. Trade Receivables, 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 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. The noncurrent portion of deferred revenue is included in "Other noncurrent liabilities" in our consolidated statements of financial position. Our contract assets and 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 deferred revenues primarily results from the timing difference between our performance obligations and the customer’s payment. We receive payments from customers based on the terms established in our contracts, which vary by contract type. Allowance for Doubtful Accounts. We maintain an allowance for doubtful accounts to provide for the estimated amount of receivables that may not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience, the age of outstanding receivables and other applicable factors. We evaluate the collectability of our trade accounts receivable on an on-going basis and write off accounts when they are deemed to be uncollectable. Cost to Fulfill. Recurring operating costs for contracts with customers are recognized as incurred. Certain eligible, nonrecurring costs incurred in the initial phases of our contracts (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 to evaluate 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. 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 from functional currencies at current exchange rates while revenues and expenses are translated from functional currencies 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 subsidiary’s functional currency. The subsidiary's functional currency is the currency of the primary economic environment in which the subsidiary 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 subsidiary at historical exchange rates while monetary assets and liabilities are remeasured to the functional currency of the subsidiary 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 of foreign exchange forward 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 derivative financial 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. Beginning in 2017, the differences between actual tax benefits realized on employee stock awards and estimated tax benefits at date of grant are adjusted to our provision for income taxes upon vesting or exercise of the stock award. 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 ("EPS"). Basic EPS excludes dilution and 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 2018 , 2017 and 2016 from our diluted EPS calculation. We include performance stock unit awards in the dilutive potential common shares when they become contingently issuable per the authoritative guidance and exclude the awards when they are not contingently issuable. Recently Adopted Accounting Pronouncements Date Issued and Topic Date Adopted and Method Description Impact May 2014 January 1, 2018 Modified Retrospective 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. See Note 3 for the impact of adoption of this standard. November 2016 Statement of Cash Flows January 1, 2018 Retrospective This update requires restricted cash to be included with cash and cash equivalents when reconciling the beginning and ending amounts on the statement of cash flows. It also requires a reconciliation of such totals to the amounts on the statement of financial position and disclosure as to the nature of the restrictions. There were no restricted cash balances as of December 31, 2018. The adoption of this update had no impact on our financial statements for the year ended December 31, 2018. February 2018 January 1, 2018 In the period of adoption This update provides an option for entities to reclassify stranded tax effects caused by the recently-enacted Tax Cuts and Jobs Act ("Tax Reform Act") from accumulated other comprehensive income

Internal Investigation and Rela

Internal Investigation and Related Matters	12 Months Ended
	Dec. 31, 2018
Internal Investigation and Related Matters [Abstract]
Internal Investigation and Related Matters	uring the year ended December 31, 2016, we recorded out-of-period corrections related to $4 million of potentially improper payments between 2009 and 2016 that had been previously capitalized when they should have been expensed. These out-of-period corrections were not material to any previously issued financial statements. There were no adjustments recorded during 2018 and 2017 related to the amounts then under investigation. On February 15, 2019, we announced a resolution of the previously disclosed investigations by the U.S. Department of Justice ("DOJ") and the U.S. Securities and Exchange Commission ("SEC") into the matters that were the subject of our internal investigation. The resolution required the Company to pay approximately $28 million to the DOJ and SEC, an amount consistent with the Company’s accrual ("FCPA Accrual") recorded during the quarter ended September 30, 2018 and reflected in the caption "Accrued expenses and other current liabilities" in our consolidated statement of financial position.

Revenues (Notes)

Revenues (Notes)	12 Months Ended
	Dec. 31, 2018
Revenues [Abstract]
Revenue from Contract with Customer [Text Block]	Adoption of Accounting Standards Codification ("ASC") Topic 606, “Revenue from Contracts with Customers” ("New Revenue Standard") On January 1, 2018, we adopted the New Revenue Standard using the modified retrospective method applied to contracts that were not completed as of January 1, 2018. Results for reporting periods beginning on or after January 1, 2018 are presented under the New Revenue Standard, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting policies. For contracts that were modified before the effective date, the Company aggregated the effect of all contract modifications prior to identifying performance obligations and allocating transaction price in accordance with the practical expedient ASC 606-10-65-1-(f)-4. Upon adoption of the New Revenue Standard on January 1, 2018, we recorded a net increase to opening retained earnings of approximately $121 million , after a tax impact of $37 million . The impact of adoption primarily relates to (1) changes in the method used to measure progress on our fixed-price application maintenance, consulting and business process services contracts, (2) the longer period of amortization for costs to fulfill a contract, (3) the timing of revenue recognition and allocation of purchase price on our software license contracts, (4) the reclassification of balances representing receivables, as defined by the New Revenue Standard, from "Unbilled accounts receivable" to "Trade accounts receivable, net" in our consolidated statement of financial position, (5) the reclassification of balances representing contract assets, as defined by the New Revenue Standard, from "Unbilled accounts receivable" to "Other current assets" in our consolidated statement of financial position, as well as (6) the income tax impact of the above items, as applicable. The following tables compare the financial statement line items materially affected by the adoption of the New Revenue Standard as of and for the year ended December 31, 2018 to the pro-forma amounts had the previous guidance been in effect ("Pro-forma Amounts"): December 31, 2018 As Reported Pro-forma Amounts Impacts of the New Revenue Standard (in millions) Assets: Trade accounts receivable, net (1), (2) $ 3,257 $ 3,115 $ 142 Unbilled accounts receivable (1), (3) — 485 (485 ) Other current assets (2), (3) 909 604 305 Total current assets (38 ) Other noncurrent assets (4) 689 615 74 Total assets $ 36 Liabilities: Deferred revenue, current (2) $ 286 $ 498 $ (212 ) Total current liabilities (212 ) Deferred revenue, noncurrent (2) 62 108 (46 ) Deferred income tax liabilities, net (5) 183 118 65 Total liabilities (193 ) Stockholders’ equity: Retained earnings 11,485 11,256 229 Total stockholders’ equity 229 Total liabilities and stockholders’ equity $ 36 Year Ended December 31, 2018 As Reported Pro-forma Amounts Impacts of the New Revenue Standard (in millions) Revenues (2) $ 16,125 $ 16,029 $ 96 Cost of revenues (4) 9,838 9,876 (38 ) Selling, general and administrative expenses 3,026 3,026 — Depreciation and amortization expense 460 460 — Income from operations 2,801 2,667 134 Other income (expense), net (4 ) (5 ) 1 Income before provision for income taxes (5) 2,797 2,662 135 Provision for income taxes (698 ) (671 ) (27 ) Income (loss) from equity method investment 2 2 — Net income $ 2,101 $ 1,993 $ 108 Basic earnings per share $ 3.61 $ 3.42 $ 0.19 Diluted earnings per share $ 3.60 $ 3.41 $ 0.19 (1) Reflects the reclassification of balances representing receivables, as defined by the New Revenue Standard, from Unbilled accounts receivable to Trade accounts receivable, net. (2) Reflects the impact of changes in the method used to measure progress on our fixed-price application maintenance, consulting and business process services contracts and the timing of revenue recognition and allocation of purchase price on our software license contracts. (3) Reflects the reclassification of balances representing contract assets, as defined by the New Revenue Standard, from Unbilled accounts receivable to Other current assets. (4) Reflects the impact of a longer period of amortization for costs to fulfill a contract as well as a change in the methodology of assessing the recoverability of such costs. (5) Reflects the income tax impact of the above items. Costs to Fulfill The following table presents information related to the capitalized costs to fulfill, such as set-up or transition activities, for the year ended December 31, 2018 . 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 statements of operations. Costs to obtain contracts were immaterial for the periods disclosed. Costs to Fulfill (in millions) Balance - January 1, 2018 $ 303 Amortization expense (70 ) Costs capitalized 170 Other (3 ) Balance - December 31, 2018 $ 400 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: Contract Assets (in millions) Balance - January 1, 2018 $ 306 Revenues recognized during the period but not billed 285 Amounts reclassified to accounts receivable (282 ) Other (4 ) Balance - December 31, 2018 $ 305 The table below shows significant movements in the deferred revenue balances (current and noncurrent) for the period disclosed: Deferred Revenue (in millions) Balance - January 1, 2018 $ 431 Amounts billed but not recognized as revenues 204 Revenues recognized related to the opening balance of deferred revenue (284 ) Other (3 ) Balance - December 31, 2018 $ 348 Revenues recognized during the year ended December 31, 2018 for performance obligations satisfied or partially satisfied in previous periods were immaterial. Remaining Performance Obligations As of December 31, 2018, the aggregate amount of transaction price allocated to remaining performance obligations, was $1,852 million , of which approximately 68% 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 ASC 606, (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. Disaggregation of Revenues The table below presents disaggregated revenues from contracts with customers by customer 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. 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 Rest of 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 (1) $ 3,571 $ 2,553 $ 2,024 $ 1,161 $ 9,309 Outsourcing services (2) 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 (1) Our consulting and technology services include consulting, application development, systems integration, and application testing services as well as software solutions and related services. (2) Our outsourcing services include application maintenance, infrastructure and business process services.

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Business Combinations	All acquisitions completed during the three years ended December 31, 2018, 2017 and 2016 were not individually material to our operations or cash flow. 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 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. 2018 In 2018, we completed five business combinations for total consideration of approximately $1,122 million . These acquisitions were (a) Bolder Healthcare Solutions ("Bolder"), a provider of revenue cycle management solutions to the healthcare industry in the United States; (b) Hedera Consulting, a business advisory and data analytics service provider in Belgium and the Netherlands; (c) Softvision, a digital engineering and consulting company with significant operations in Romania and India that focuses on agile development of custom cloud-based software and platforms for customers primarily in the United States; (d) ATG, a United States based consulting company that helps companies plan, implement and optimize automated cloud-based quote-to-cash business processes and technologies; and (e) SaaSfocus, a Salesforce services provider in Australia. The allocation of purchase price to the fair value of the aggregate assets acquired and liabilities assumed was as follows: Softvision Bolder Others Total Weighted Average Useful Life ( dollars in millions) Cash $ 4 $ 7 $ 4 $ 15 Current assets 54 32 15 101 Property, plant and equipment and other noncurrent assets 7 7 1 15 Non-deductible goodwill 385 335 76 796 Customer relationship intangible assets 133 113 30 276 10.3 years Other intangible assets 9 17 1 27 3.7 years Trademark — 9 — 9 Indefinite Current liabilities (47 ) (11 ) (9 ) (67 ) Noncurrent liabilities (4 ) (37 ) (9 ) (50 ) Purchase price $ 541 $ 472 $ 109 $ 1,122 For acquisitions completed in 2018, 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. 2017 In 2017, we completed five business combinations for total consideration of approximately $233 million . These acquisitions were (a) an intelligent products and solutions company based in Japan specializing in digital strategy, product design and engineering, the internet of things, and enterprise mobility that expands our digital transformation portfolio and capabilities, (b) a U.S. healthcare management consulting firm that strengthens our consulting service offerings within the healthcare consulting market, (c) a leading national provider of business process services to the U.S. government healthcare market that further strengthens our business process-as-a-service solutions for government and public health programs, (d) a provider of digital experience and marketing solutions for some of the world's most recognized brands and an independent Adobe partner in Europe that will enhance our ability to deliver business critical digital experience solutions, and (e) an independent full-service digital agency in the UK specializing in customer experience, digital strategy, technology and content creation that will enhance and expand our digital interactive expertise in experience design, human science-driven insights and analytics. The allocation of purchase price to the fair value of the aggregate assets acquired and liabilities assumed was as follows: Fair Value Weighted Average Useful Life (in millions) Cash $ 8 Current assets 47 Property, plant and equipment and other noncurrent assets 19 Non-deductible goodwill 125 Customer relationship intangible assets 147 10.6 years Other intangible assets 4 2.4 years Current liabilities (50 ) Noncurrent liabilities (67 ) Purchase price $ 233 2016 In 2016, we completed eight business combinations for total consideration of approximately $287 million . These transactions included (a) an acquisition of a global consulting and technology services company that strengthens and expands our digital capabilities to deliver cloud-based application services, (b) three acquisitions of delivery centers spanning several industries such as oil and gas services, steel and metal products, and banking and insurance to enhance our delivery capabilities across Europe along with multi-year service agreements, (c) an acquisition of tangible property, an assembled workforce and a multi-year service agreement which qualifies as a business combination under accounting guidance, (d) an acquisition of a global consulting company that offers digital innovation, strategy, design and technology services, (e) an acquisition of a digital marketing and customer experience agency that expands our digital business capabilities across Europe, and (f) an acquisition of an Australia-based consulting, business transformation and technology services provider in the insurance industry. The allocation of purchase price to the fair value of the aggregate assets acquired and liabilities assumed was as follows: Fair Value Weighted Average Useful Life (in millions) Cash $ 17 Current assets 84 Property, plant and equipment and other noncurrent assets 53 Non-deductible goodwill 157 Customer relationship intangible assets 199 6.6 years Other intangible assets 1 3.3 years Current liabilities (173 ) Noncurrent liabilities (51 ) Purchase price $ 287

Realignment Charges

Realignment Charges	12 Months Ended
	Dec. 31, 2018
Realignment Charges [Abstract]
Realignment Charges	In 2017, we began a realignment of our business to accelerate the shift to digital services and solutions while improving the overall efficiency of our operations. As part of this realignment, we incurred charges that included severance costs, lease termination costs and advisory fees related to non-routine shareholder matters and charges related to the development of our realignment and capital return plans. The total costs related to the realignment are reported in "Selling, general and administrative expenses" in our consolidated statements of operations. The accrued realignment costs as of December 31, 2018 and 2017 were immaterial. Realignment charges were as follows: Years Ended December 31, 2018 2017 (in millions) Severance costs $ 18 $ 53 Advisory fees — 18 Lease termination costs 1 1 Total realignment costs $ 19 $ 72 There were no realignment charges incurred in 2016.

Investments

Investments	12 Months Ended
	Dec. 31, 2018
Investments [Abstract]
Investments	Our investments were as follows as of December 31: 2018 2017 (in millions) Short-term investments: Equity investment securities $ 25 $ 25 Available-for-sale investment securities 1,760 1,972 Held-to-maturity investment securities 1,065 745 Time deposits 500 (1) 389 Total short-term investments $ 3,350 $ 3,131 Long-term investments: Equity and cost method investments $ 74 $ 74 Held-to-maturity investment securities 6 161 Total long-term investments $ 80 $ 235 (1) Includes $423 million in restricted time deposits as of December 31, 2018. See Note 11 . Equity Investment Securities Our equity investment securities consist of a U.S. dollar denominated investment in a fixed income mutual fund. Unrealized losses for the years ended December 31, 2018 and 2017 were immaterial. The value of the fixed income mutual fund is based on the net asset value ("NAV") of the fund, with appropriate consideration of the liquidity and any restrictions on disposition of our investment in the fund. There were no realized gains or losses on equity securities during the years ended December 31, 2018 and 2017. Available-for-Sale Investment Securities Our available-for-sale investment securities consist of U.S. dollar denominated investments primarily in U.S. Treasury notes, U.S. government agency debt securities, municipal debt securities, non-U.S. government debt securities, U.S. and international corporate bonds, certificates of deposit, commercial paper, debt securities issued by supranational institutions, and asset-backed securities, including securities backed by auto loans, credit card receivables, and other receivables. Our investment guidelines are to purchase securities which are investment grade at the time of acquisition. We monitor the credit ratings of the securities in our portfolio on an ongoing basis. The amortized cost, gross unrealized gains and losses and fair value of our available-for-sale investment securities were as follows at December 31: 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in millions) U.S. Treasury and agency debt securities $ 630 $ 1 $ (6 ) $ 625 Corporate and other debt securities 420 — (4 ) 416 Certificates of deposit and commercial paper 296 — — 296 Asset-backed securities 336 — (2 ) 334 Municipal debt securities 90 — (1 ) 89 Total available-for-sale investment securities $ 1,772 $ 1 $ (13 ) $ 1,760 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in millions) U.S. Treasury and agency debt securities $ 667 $ — $ (6 ) $ 661 Corporate and other debt securities 439 — (2 ) 437 Certificates of deposit and commercial paper 450 — — 450 Asset-backed securities 297 — (2 ) 295 Municipal debt securities 130 — (1 ) 129 Total available-for-sale investment securities $ 1,983 $ — $ (11 ) $ 1,972 The fair value and related unrealized losses of our available-for-sale investment securities in a continuous unrealized loss position for less than 12 months and for 12 months or longer were as follows as of December 31: 2018 Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in millions) U.S. Treasury and agency debt securities $ 84 $ — $ 446 $ (6 ) $ 530 $ (6 ) Corporate and other debt securities 108 (1 ) 254 (3 ) 362 (4 ) Certificates of deposit and commercial paper 295 — — — 295 — Asset-backed securities 93 — 179 (2 ) 272 (2 ) Municipal debt securities 17 — 64 (1 ) 81 (1 ) Total $ 597 $ (1 ) $ 943 $ (12 ) $ 1,540 $ (13 ) 2017 Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in millions) U.S. Treasury and agency debt securities $ 519 $ (4 ) $ 124 $ (2 ) $ 643 $ (6 ) Corporate and other debt securities 297 (1 ) 126 (1 ) 423 (2 ) Certificates of deposit and commercial paper 49 — — — 49 — Asset-backed securities 193 (1 ) 94 (1 ) 287 (2 ) Municipal debt securities 107 (1 ) 18 — 125 (1 ) Total $ 1,165 $ (7 ) $ 362 $ (4 ) $ 1,527 $ (11 ) The unrealized losses for the above securities as of December 31, 2018 and 2017 are primarily attributable to changes in interest rates. At each reporting date, we perform an evaluation of impaired available-for-sale securities to determine if the unrealized losses are other-than-temporary. As of December 31, 2018 , we do not consider any of the investments to be other-than-temporarily impaired. The gross unrealized gains and losses in the above tables were recorded, net of tax, in "Accumulated other comprehensive income (loss)" in our consolidated statements of financial position. The contractual maturities of our fixed income available-for-sale investment securities as of December 31, 2018 are set forth in the following table: Amortized Cost Fair Value (in millions) Due within one year $ 569 $ 567 Due after one year up to two years 544 537 Due after two years up to three years 267 265 Due after three years 56 57 Asset-backed securities 336 334 Total available-for-sale investment securities $ 1,772 $ 1,760 Asset-backed securities were excluded from the maturity categories because the actual maturities may differ from the contractual maturities since the underlying receivables may be prepaid without penalties. Further, actual maturities of debt securities may differ from those presented above since certain obligations provide the issuer the right to call or prepay the obligation prior to scheduled maturity without penalty. 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: 2018 2017 2016 (in millions) Proceeds from sales of available-for-sale investment securities $ 1,285 $ 2,922 $ 3,541 Gross gains $ — $ 1 $ 5 Gross losses (4 ) (3 ) (4 ) Net realized (losses) gains on sales of available-for-sale investment securities $ (4 ) $ (2 ) $ 1 Held-to-Maturity Investment Securities Our held-to-maturity investment securities consist of Indian rupee denominated investments primarily in commercial paper, international corporate bonds and government debt securities. Our investment guidelines are to purchase securities that are investment grade at the time of acquisition. We monitor the credit ratings of the securities in our portfolio on an ongoing basis. The amortized cost, gross unrealized gains and losses and fair value of held-to-maturity investment securities were as follows at December 31: 2018 Amortized Unrealized Unrealized Fair (in millions) Short-term investments: Corporate and other debt securities $ 546 $ — $ — $ 546 Commercial paper 519 — (1 ) 518 Total short-term held-to-maturity investments 1,065 — (1 ) 1,064 Long-term investments: Corporate and other debt securities 6 — — 6 Total held-to-maturity investment securities $ 1,071 $ — $ (1 ) $ 1,070 2017 Amortized Unrealized Unrealized Fair (in millions) Short-term investments: Corporate and other debt securities $ 346 $ — $ (1 ) $ 345 Commercial paper 399 — (2 ) 397 Total short-term held-to-maturity investments 745 — (3 ) 742 Long-term investments: Corporate and other debt securities 161 — (1 ) 160 Total held-to-maturity investment securities $ 906 $ — $ (4 ) $ 902 The fair value and related unrealized losses of held-to-maturity investment securities in a continuous unrealized loss position for less than 12 months and for 12 months or longer were as follows as of December 31: 2018 Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in millions) Corporate and other debt securities $ 263 $ — $ 57 $ — $ 320 $ — Commercial paper 268 (1 ) — — 268 (1 ) Total $ 531 $ (1 ) $ 57 $ — $ 588 $ (1 ) 2017 Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in millions) Corporate and other debt securities $ 473 $ (2 ) $ — $ — $ 473 $ (2 ) Commercial paper 394 (2 ) — — 394 (2 ) Total $ 867 $ (4 ) $ — $ — $ 867 $ (4 ) At each reporting date, the Company performs an evaluation of held-to-maturity securities to determine if the unrealized losses are other-than-temporary. We do not consider any of the investments to be other-than-temporarily impaired as of December 31, 2018 . The contractual maturities of our fixed income held-to-maturity investment securities as of December 31, 2018 are set forth in the following table: Amortized Cost Fair Value (in millions) Due within one year $ 1,065 $ 1,064 Due after one year up to two years 6 6 Total held-to-maturity investment securities $ 1,071 $ 1,070 During the years ended December 31, 2018 and 2017, there were no transfers of investments between our available-for-sale and held-to-maturity investment portfolios. Equity and Cost Method Investments As of December 31, 2018 and 2017, we had equity method investments of $66 million and $67 million , respectively, which primarily consist 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. As of December 31, 2018 and 2017, we had cost method investments of $8 million and $7 million , respectively.

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment, Net [Abstract]
Property and Equipment, net	Property and equipment were as follows as of December 31: Estimated Useful Life (Years) 2018 2017 (in millions) Buildings 30 $ 839 $ 836 Computer equipment 3 – 5 412 364 Computer software 3 – 8 721 594 Furniture and equipment 5 – 9 639 511 Land 19 19 Leasehold land lease term 60 63 Capital work-in-progress 156 145 Leasehold improvements Shorter of the lease term or the life of the leased asset 338 308 Sub-total 3,184 2,840 Accumulated depreciation and amortization (1,790 ) (1,516 ) Property and equipment, net $ 1,394 $ 1,324 Depreciation and amortization expense related to property and equipment was $347 million, $313 million and $266 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The gross amount of property and equipment recorded under capital leases was $73 million and $44 million as of December 31, 2018 and 2017, respectively. Accumulated amortization and amortization expense related to capital lease assets were immaterial for the periods presented. The gross amount of property and equipment recorded for software to be sold, leased or marketed in the caption "Computer software" above was $85 million and $52 million , as of December 31, 2018 and 2017, respectively. Accumulated amortization for software to be sold, leased or marketed was $24 million and $12 million as of December 31, 2018 and 2017, respectively. Amortization expense for software to be sold, leased or marketed recorded as property and equipment was $14 million for the year ended December 31, 2018 and was immaterial for the years ended December 31, 2017 and 2016.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, net	12 Months Ended
	Dec. 31, 2018
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, 2018 and 2017 : Segment January 1, 2018 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments December 31, 2018 (in millions) Financial Services $ 265 $ 152 $ (6 ) $ 411 Healthcare 2,106 365 (2 ) 2,469 Products and Resources 240 152 (8 ) 384 Communications, Media and Technology 93 126 (2 ) 217 Total goodwill $ 2,704 $ 795 $ (18 ) $ 3,481 Segment January 1, 2017 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments December 31, 2017 (in millions) Financial Services $ 227 $ 27 $ 11 $ 265 Healthcare 2,089 13 4 2,106 Products and Resources 159 72 9 240 Communications, Media and Technology 79 11 3 93 Total goodwill $ 2,554 $ 123 $ 27 $ 2,704 To better align our annual goodwill impairment assessment with the timing of our budget process, we elected to change the date of our annual goodwill impairment assessment from December 31 st to October 31 st . Based on our most recent goodwill impairment assessment performed during 2018, we concluded the goodwill in each of our reporting units were not at risk of impairment. We have not recognized any impairment losses on our goodwill balances to-date. Components of intangible assets were as follows as of December 31: 2018 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (in millions) Customer relationships $ 1,277 $ (398 ) $ 879 $ 1,005 $ (304 ) $ 701 Developed technology 355 (187 ) 168 333 (140 ) 193 Indefinite life trademarks 72 — 72 63 — 63 Other 64 (33 ) 31 51 (27 ) 24 Total intangible assets $ 1,768 $ (618 ) $ 1,150 $ 1,452 $ (471 ) $ 981 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 $151 million for 2018 , $130 million for 2017 and $113 million for 2016 . Of these amounts, during 2018 , 2017 and 2016 , amortization of $38 million , $35 million and $20 million, respectively, relating to customer relationship intangible assets attributable to direct revenue contracts with sellers of acquired businesses was recorded as a reduction of revenues. Estimated amortization related to our existing intangible assets for the next five years is as follows: Year Amount (in millions) 2019 $ 167 2020 158 2021 153 2022 137 2023 83

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2018
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: 2018 2017 (in millions) Compensation and benefits $ 1,216 $ 1,272 Customer volume and other incentives 323 289 Derivative financial instruments 25 5 FCPA Accrual 28 — Income taxes 162 48 Professional fees 110 100 Travel and entertainment 34 32 Other 369 325 Total accrued expenses and other current liabilities $ 2,267 $ 2,071

Debt

Debt	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Debt	In 2014, we entered into a credit agreement with a commercial bank syndicate, (as amended, the "Credit Agreement"), providing for a $1,000 million unsecured term loan and a $750 million unsecured revolving credit facility, which were due to mature in November 2019. In November 2018, we completed a debt refinancing in which we entered into a credit agreement with a new commercial bank syndicate (the "New Credit Agreement") providing for a $750 million unsecured term loan (the "New Term Loan") and a $1,750 million unsecured revolving credit facility, which are due to mature in November 2023. We are required under the New Credit Agreement to make scheduled quarterly principal payments on the New Term Loan, beginning in December 2019. The New Credit Agreement requires interest to be paid, at our option, at either the ABR or the Eurocurrency Rate (each as defined in the New Credit Agreement), plus, in each case, an Applicable Margin (as defined in the New 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 New Credit Agreement). Under the New 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 New 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, 2018 and 2017. The New 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 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 New Credit Agreement as of December 31, 2018. Short-term Debt The following summarizes our short-term debt balances as of December 31: 2018 2017 Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate (in millions) (in millions) Notes outstanding under revolving credit facility $ — not applicable $ 75 4.5 % Term loan - current maturities 9 3.3 % 100 2.4 % Total short-term debt $ 9 $ 175 Long-term Debt The following summarizes our long-term debt balances as of December 31: 2018 2017 (in millions) Term loan $ 750 $ 800 Less: Current maturities (9 ) (100 ) Deferred financing costs (5 ) (2 ) Long-term debt, net of current maturities $ 736 $ 698 The following represents the schedule of maturities of our term loan: Year Amounts (in millions) 2019 $ 9 2020 38 2021 38 2022 38 2023 627 $ 750

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
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: 2018 2017 2016 (in millions) United States $ 947 $ 810 $ 752 Foreign 1,850 1,845 1,605 Income before provision for income taxes $ 2,797 $ 2,655 $ 2,357 The provision for income taxes consisted of the following components for the years ended December 31: 2018 2017 2016 (in millions) Current: Federal and state $ 241 $ 767 $ 544 Foreign 449 262 352 Total current provision 690 1,029 896 Deferred: Federal and state 1 102 (44 ) Foreign 7 22 (47 ) Total deferred provision (benefit) 8 124 (91 ) Total provision for income taxes $ 698 $ 1,153 $ 805 During 2017, the United States enacted the Tax Reform Act, which significantly revised the U.S. corporate income tax law for tax years beginning after December 31, 2017 by (among other provisions): • reducing the U.S. federal statutory corporate income tax rate from 35% to 21% for tax years beginning after December 31, 2017; • implementing a modified territorial tax system that includes a one-time transition tax on all accumulated undistributed earnings of foreign subsidiaries; • providing for a full deduction on future dividends received from foreign affiliates; • imposing a U.S. income tax on global intangible low-taxed income ("GILTI"); and • disallowing certain deductions to foreign affiliates under the base erosion anti-avoidance tax ("BEAT"). In 2017, in accordance with the SEC Staff Accounting Bulletin No. 118 - Income Tax Accounting Implications of the Tax Cuts and Jobs Act, we recorded a one-time provisional net income tax expense of $617 million . During 2018, we recognized a $5 million reduction to the provision for income taxes as we finalized our calculation of this one-time net income tax expense bringing the final one-time cost to $612 million . We elected to pay the transition tax on undistributed earnings in installments through the year 2024. Additionally, we have adopted an accounting policy to include the tax on GILTI in the year it is incurred. During 2018, the state of New Jersey enacted comprehensive budget legislation that included various changes to the state's tax laws. This legislation did not have a material effect on our income tax provision for the fourth quarter or the full year. As a result of the enactment of the Tax Reform Act, our historical and future foreign earnings are no longer subject to U.S. federal income taxes upon repatriation, beyond the one-time transition tax. We therefore reevaluated our assertion that our foreign earnings would be indefinitely reinvested and concluded that our Indian earnings will continue to be indefinitely reinvested while historical accumulated undistributed earnings of our foreign subsidiaries, other than our Indian subsidiaries, are available for repatriation to the United States. Our assertion that our earnings in India continue to be indefinitely reinvested is consistent with our ongoing strategy to expand our Indian operations, including through infrastructure investments. As of December 31, 2018, the amount of unrepatriated Indian earnings was approximately $4,679 million . If all of our accumulated unrepatriated Indian earnings were to be repatriated, based on our current interpretation of India tax law, we estimate that we would incur an additional income tax expense of approximately $980 million . This estimate is subject to change based on tax legislation developments in India and other jurisdictions as well as judicial and interpretive developments of applicable tax laws. We are involved in an ongoing dispute with the Indian Income Tax Department ("ITD") in connection with which we received a notice in March 2018 asserting that the ITD is owed additional taxes on our previously disclosed 2016 India Cash Remittance, which was the transaction undertaken by our principal operating subsidiary in India ("CTS India") to repurchase shares from its shareholders, which are non-Indian Cognizant entities, valued at $2.8 billion . As a result of that transaction, undertaken pursuant to a plan approved by the Madras High Court in Chennai, India, we previously paid $135 million in Indian income taxes, which we believe are all the applicable taxes owed for this transaction under Indian law. The ITD is asserting that we owe an additional 33 billion Indian rupees ( $475 million at the December 31, 2018 exchange rate) related to the 2016 India Cash Remittance. In addition to the dispute on the 2016 India Cash Remittance, we are 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"), for which we also believe we have paid all the applicable taxes owed. Accordingly, we have not recorded any reserves for these matters as of December 31, 2018. The ITD Dispute is currently pending before the Madras High Court, and no final decision has been reached. In March 2018, the ITD placed an attachment on certain of our India bank accounts, relating to the 2016 India Cash Remittance. In April 2018, the Madras High Court granted our application for a stay of the actions of the ITD and lifted the ITD’s attachment of our bank accounts. As part of the interim stay order, we have deposited 5 billion Indian rupees ( $71 million at the December 31, 2018 exchange rate) representing 15% of the disputed tax amount related to the 2016 India Cash Remittance, with the ITD. This amount is presented in "Other current assets" on our consolidated statement of financial position. In addition, in April 2018 the court placed a lien on certain time deposits of CTS India in the amount of 28 billion Indian rupees ( $404 million at the December 31, 2018 exchange rate), which is the remainder of the disputed tax amount related to the 2016 India Cash Remittance. The affected time deposits are considered restricted assets and we have reported them in “Short-term investments” on our consolidated statement of financial position. As of December 31, 2018, the restricted time deposits balance was $423 million , including accumulated interest. There were no restricted time deposits as of December 31, 2017. The reconciliation between our effective income tax rate and the U.S. federal statutory rate were as follows for the years ended December 31: 2018 % 2017 % 2016 % (Dollars in millions) Tax expense, at U.S. federal statutory rate $ 587 21.0 $ 929 35.0 $ 825 35.0 State and local income taxes, net of federal benefit 56 2.0 39 1.5 42 1.8 Non-taxable income for Indian tax purposes (146 ) (5.2 ) (216 ) (8.2 ) (203 ) (8.6 ) Rate differential on foreign earnings 206 7.4 (76 ) (2.9 ) (55 ) (2.3 ) Net impact related to the implementation of the Tax Reform Act (5 ) (0.2 ) 617 23.2 — — India Cash Remittance — — — — 238 10.1 Recognition of previously unrecognized income tax benefits related to uncertain tax positions (12 ) (0.4 ) (73 ) (2.7 ) (16 ) (0.7 ) Credits and other incentives (19 ) (0.7 ) (37 ) (1.4 ) (57 ) (2.4 ) Other 31 1.1 (30 ) (1.1 ) 31 1.3 Total provision for income taxes $ 698 25.0 $ 1,153 43.4 $ 805 34.2 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: 2018 2017 (in millions) Deferred income tax assets: Net operating losses $ 13 $ 15 Revenue recognition 51 55 Compensation and benefits 133 125 Stock-based compensation 17 14 Minimum alternative tax ("MAT") and other credits 340 369 Other accrued expenses 60 22 614 600 Less: valuation allowance (11 ) (10 ) Deferred income tax assets, net 603 590 Deferred income tax liabilities: Depreciation and amortization 256 209 Deferred costs 79 65 Other 9 44 Deferred income tax liabilities 344 318 Net deferred income tax assets $ 259 $ 272 At December 31, 2018 , we had foreign and U.S. net operating loss carryforwards of approximately $39 million and $10 million, respectively. We have recorded valuation allowances on certain foreign net operating loss carryforwards. As of December 31, 2018 and 2017 , deferred income tax assets related to the MAT were approximately $228 million and $278 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 existing MAT assets expire between March 2024 and March 2032 and we expect to fully utilize them within the applicable expiration periods, which was extended to 15 years from 10 years by the 2017 Union Budget of India. Our Indian subsidiaries, collectively referred to as Cognizant India, are primarily export-oriented and are eligible for certain income tax holiday benefits granted by the government of India for export activities conducted within Special Economic Zones ("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 2026 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 34.9% . In addition, all Indian profits, including those generated within SEZs, are subject to the MAT, at the rate of 21.6% . For the years ended December 31, 2018 , 2017 and 2016 , 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 approximately $146 million, $217 million and $203 million, respectively, and increase diluted EPS by $0.25 , $0.36 and $0.33 , respectively. 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 Internal Revenue Service 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 before the taxing authorities in some of our most significant jurisdictions applications for Advance Pricing Agreements. 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: 2018 2017 2016 (in millions) Balance, beginning of year $ 97 $ 151 $ 139 Additions based on tax positions related to the current year 8 17 11 Additions for tax positions of prior years 19 2 19 Additions for tax positions of acquired subsidiaries 6 — — Reductions for tax positions due to lapse of statutes of limitations (12 ) (41 ) (15 ) Reductions for tax positions of prior years — (32 ) (1 ) Settlements — — — Foreign currency exchange movement (1 ) — (2 ) Balance, end of year $ 117 $ 97 $ 151 At December 31, 2018 , the unrecognized income tax benefits would affect our effective income tax rate, if recognized. While the Company believes uncertain tax positions may be settled or resolved within the next twelve months, it is difficult to estimate the income tax impact of these potential resolutions at this time. We recognize accrued interest and any penalties associated with uncertain tax positions as part of our provision for income taxes. The total amount of accrued interest and penalties at December 31, 2018 and 2017 was approximately $11 million and $8 million, respectively, and relates to U.S. and foreign tax matters. The amounts of interest and penalties recorded in the provision for income taxes in 2018 , 2017 and 2016 were immaterial.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	In the normal course of business, we use foreign exchange forward contracts to manage foreign currency exchange rate risk. The estimated fair value of the foreign exchange forward contracts considers the following items: discount rate, timing and amount of cash flow and counterparty credit risk. Derivatives may give rise to credit risks 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 entering into derivative transactions only with highly-rated financial institutions, limiting 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 forward contracts set forth in the below table are subject to master netting arrangements, such as the International Swaps and Derivatives Association ("ISDA"), 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 forward contracts 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 forward 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: 2018 2017 Designation of Derivatives Location on Statement of Financial Position Assets Liabilities Assets Liabilities (in millions) Foreign exchange forward contracts - Designated as cash flow hedging instruments Other current assets $ 11 $ — $ 134 $ — Other noncurrent assets 15 — 20 — Accrued expenses and other current liabilities — 21 — — Other noncurrent liabilities — 9 — — Total 26 30 154 — Foreign exchange forward contracts - Not designated as cash flow hedging instruments Other current assets 1 — — — Accrued expenses and other current liabilities — 4 — 5 Total 1 4 — 5 Total $ 27 $ 34 $ 154 $ 5 Cash Flow Hedges We have entered into a series of foreign exchange forward 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 exchange rates on future operating costs and are scheduled to mature each month during 2019 and 2020 . Under these contracts, we purchase Indian rupees and sell U.S. dollars. The changes in fair value of these contracts are initially reported in the caption "Accumulated other comprehensive income (loss)" in our consolidated statements of financial position and are subsequently reclassified to earnings in the same period the forecasted Indian rupee denominated payments are recorded in earnings. As of December 31, 2018 , we estimate that $9 million, net of tax, of the net losses related 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 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: 2018 2017 (in millions) 2018 $ — $ 1,185 2019 1,388 720 2020 780 — Total notional value of contracts outstanding $ 2,168 $ 1,905 Net unrealized (losses) gains included in accumulated other comprehensive income (loss), net of taxes $ (3 ) $ 115 Upon settlement or maturity of the cash flow hedge contracts, we record the related gains or losses, based on our designation at the commencement of the contract, with the related hedged Indian rupee denominated expense reported within the caption "Cost of revenues" and "Selling, general and administrative expenses" in our consolidated statements of operations. Hedge ineffectiveness was immaterial for all periods presented. The following table provides information on the location and amounts of pre-tax gains and losses on our cash flow hedges for the year ended December 31: Change in Derivative Gains/Losses Recognized in Accumulated Other Comprehensive Income (Loss) (effective portion) Location of Net Derivative Gains Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion) Net Gains Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion) 2018 2017 2018 2017 (in millions) Foreign exchange forward contracts - Designated as cash flow hedging instruments $ (87 ) $ 232 Cost of revenues $ 61 $ 109 Selling, general and administrative expenses 10 20 Total $ 71 $ 129 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 the British pound, Indian rupee and Euro. We entered into a series of foreign exchange forward contracts that are scheduled to mature in 2019. Realized gains or losses and changes in the estimated fair value of these derivative financial instruments are recorded in the caption "Foreign currency exchange gains (losses), net" in 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: 2018 2017 Notional Market Value Notional Market Value (in millions) Contracts outstanding $ 507 $ (3 ) $ 255 $ (5 ) The following table provides information on the location and amounts of realized and unrealized pre-tax gains and losses on our other derivative financial instruments for the year ended December 31: Location of Net Gains (Losses) on Derivative Instruments Amount of Net Gains (Losses) on Derivative Instruments 2018 2017 (in millions) Foreign exchange forward contracts - Not designated as hedging instruments Foreign currency exchange gains (losses), net $ 31 $ (23 ) 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, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	We measure our cash equivalents, investments and foreign exchange forward 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, 2018 : Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 103 $ — $ — $ 103 Bank deposits — 32 — 32 Certificates of deposit and commercial paper — 68 — 68 Total cash equivalents 103 100 — 203 Short-term investments: Time deposits (1) — 500 — 500 Available-for-sale investment securities: U.S. Treasury and agency debt securities 570 55 — 625 Corporate and other debt securities — 416 — 416 Certificates of deposit and commercial paper — 296 — 296 Asset-backed securities — 334 — 334 Municipal debt securities — 89 — 89 Total available-for-sale investment securities 570 1,190 — 1,760 Held-to-maturity investment securities: Corporate and other debt securities — 546 — 546 Commercial paper — 518 — 518 Total short-term held-to-maturity investment securities — 1,064 — 1,064 Total short-term investments (2) 570 2,754 — 3,324 Long-term investments: Held-to-maturity investment securities: Corporate and other debt securities — 6 — 6 Total long-term held-to-maturity investment securities — 6 — 6 Total long-term investments (3) — 6 — 6 Derivative financial instruments - foreign exchange forward contracts: Other current assets — 12 — 12 Accrued expenses and other current liabilities — (25 ) — (25 ) Other noncurrent assets — 15 — 15 Other noncurrent liabilities — (9 ) — (9 ) Total $ 673 $ 2,853 $ — $ 3,526 ________________ (1) Includes $423 million in restricted time deposits. See Note 11 . (2) Excludes an equity security invested in a mutual fund valued at $25 million based on the NAV of the fund. (3) Excludes equity and cost method investments of $74 million at December 31, 2018. The following table summarizes our financial assets and (liabilities) measured at fair value on a recurring basis as of December 31, 2017 : Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 334 $ — $ — $ 334 Bank deposits — 80 — 80 Commercial paper — 386 — 386 Total cash equivalents 334 466 — 800 Short-term investments: Time deposits — 389 — 389 Available-for-sale investment securities: U.S. Treasury and agency debt securities 585 76 — 661 Corporate and other debt securities — 437 — 437 Certificates of deposit and commercial paper — 450 — 450 Asset-backed securities — 295 — 295 Municipal debt securities — 129 — 129 Total available-for-sale investment securities 585 1,387 — 1,972 Held-to-maturity investment securities: Corporate and other debt securities — 345 — 345 Commercial Paper — 397 — 397 Total short-term held-to-maturity investment securities — 742 — 742 Total short-term investments (1) 585 2,518 — 3,103 Long-term investments: Held-to-maturity investment securities: Corporate and other debt securities — 160 — 160 Total long-term held-to-maturity investment securities — 160 — 160 Total long-term investments (2) — 160 — 160 Derivative financial instruments - foreign exchange forward contracts: Other current assets — 134 — 134 Accrued expenses and other current liabilities — (5 ) — (5 ) Other noncurrent assets — 20 — 20 Total $ 919 $ 3,293 $ — $ 4,212 ________________ (1) Excludes an equity security invested in a mutual fund valued at $25 million based on the NAV of the fund. (2) Excludes equity and cost method investments of $74 million at December 31, 2017. We measure the fair value of money market funds and U.S. Treasury securities based on quoted prices in active markets for identical assets and therefore classify these assets as Level 1. The fair value of commercial paper, certificates of deposit, U.S. government agency securities, municipal debt securities, debt securities issued by supranational institutions, U.S. and international corporate bonds and foreign government debt securities 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. We measure the fair value of our asset-backed securities using model-driven valuations based on significant inputs derived from or corroborated by observable market data such as dealer quotes, available trade information, spread data, current market assumptions on prepayment speeds and defaults and historical data on deal collateral performance. The carrying value of the time deposits approximated fair value as of December 31, 2018 and 2017 . 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. The amounts are aggregated by type of contract and maturity. During the years ended December 31, 2018 , 2017 and 2016 , there were no transfers among Level 1, Level 2 or Level 3 financial assets and liabilities.

Stockholder's Equity

Stockholder's Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	Stock Repurchase Program In November 2018, the Board of Directors approved an amendment to the then in effect stock repurchase program. Under this amended stock repurchase program, we are authorized to repurchase $5.5 billion of our Class A common stock, excluding fees and expenses, through December 31, 2020. These share repurchases can be made through open market purchases, including under a trading plan adopted pursuant to Rule 10b5-1 of the Exchange Act, or in private transactions, including through ASR agreements entered into with financial institutions, in accordance with applicable federal securities laws. The timing of repurchases and the exact number of shares to be purchased are determined by management, in its discretion, or pursuant to a Rule 10b5-1 trading plan, and will depend upon market conditions and other factors. As of December 31, 2018 , the remaining available balance under the Board of Directors' authorized stock repurchase program was $2.5 billion . The Company’s share repurchase activity was as follows for the years ended December 31: 2018 2017 2016 Shares Amount Shares Amount Shares Amount (in millions) Open-market share repurchases 4 $ 275 — $ — 8 $ 440 ASRs 12 900 28 1,800 — — Share repurchases in connection with stock-based compensation plans 1 86 1 89 1 72 17 $ 1,261 29 $ 1,889 9 $ 512 In 2018 and 2017, we entered into several ASR agreements, referred to collectively as the 2018 and 2017 ASRs, with certain financial institutions under our stock repurchase program. Under the terms of the 2018 and 2017 ASRs and in exchange for up-front payments of $900 million and $1,800 million , respectively, the financial institutions delivered 12 million and 28 million shares, respectively. The final number of shares repurchased was based on the final volume-weighted average price of the Company's Class A common stock during the purchase period less the negotiated discount. The 2018 and 2017 ASRs met all of the applicable criteria for equity classification, and therefore were not accounted for as derivative instruments. There are no outstanding ASR agreements as of December 31, 2018. Additionally, stock repurchases were made in connection with our stock-based compensation plans, whereby Company shares were tendered by employees for payment of applicable statutory tax withholdings. In 2017, we also repurchased a limited number of shares from employees at the repurchase date market price. Combined, such repurchases in 2018, 2017 and 2016 totaled approximately 1 million shares each, at an aggregate cost of $86 million, $89 million , and $72 million , respectively. Accumulated Other Comprehensive Income (Loss) Changes in "Accumulated other comprehensive income (loss)" by component were as follows for the year ended December 31, 2018 : 2018 Before Tax Amount Tax Effect Net of Tax Amount (in millions) Foreign currency translation adjustments: Beginning balance $ (38 ) $ — $ (38 ) Change in foreign currency translation adjustments (70 ) 5 (65 ) Ending balance $ (108 ) $ 5 $ (103 ) Unrealized (losses) on available-for-sale investment securities: Beginning balance $ (11 ) $ 4 $ (7 ) Cumulative effect of change in accounting principle (1) — (1 ) (1 ) Net unrealized losses arising during the period (5 ) 2 (3 ) Reclassification of net losses to Other, net 4 (1 ) 3 Net change (1 ) — (1 ) Ending balance $ (12 ) $ 4 $ (8 ) Unrealized gains (losses) on cash flow hedges: Beginning balance $ 154 $ (39 ) $ 115 Unrealized (losses) arising during the period (87 ) 23 (64 ) Reclassifications of net (gains) to: Cost of revenues (61 ) 15 (46 ) Selling, general and administrative expenses (10 ) 2 (8 ) Net change (158 ) 40 (118 ) Ending balance $ (4 ) $ 1 $ (3 ) Accumulated other comprehensive income (loss): Beginning balance $ 105 $ (35 ) $ 70 Other comprehensive income (loss) (229 ) 45 (184 ) Ending balance $ (124 ) $ 10 $ (114 ) (1) Reflects the adoption of accounting standards as described in Note 1 . Changes in "Accumulated other comprehensive income (loss)" by component were as follows for the years ended December 31, 2017 and 2016 : 2017 2016 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Tax Net of Tax (in millions) Foreign currency translation adjustments: Beginning balance $ (149 ) $ — $ (149 ) $ (90 ) $ — $ (90 ) Change in foreign currency translation adjustments 111 — 111 (59 ) — (59 ) Ending balance $ (38 ) $ — $ (38 ) $ (149 ) $ — $ (149 ) Unrealized (losses) on available-for-sale investment securities: Beginning balance $ (6 ) $ 2 $ (4 ) $ (7 ) $ 3 $ (4 ) Net unrealized (losses) gains arising during the period (7 ) 3 (4 ) 5 (2 ) 3 Reclassification of net losses (gains) to Other, net 2 (1 ) 1 (4 ) 1 (3 ) Net change (5 ) 2 (3 ) 1 (1 ) — Ending balance $ (11 ) $ 4 $ (7 ) $ (6 ) $ 2 $ (4 ) Unrealized gains (losses) on cash flow hedges: Beginning balance $ 51 $ (12 ) $ 39 $ (15 ) $ 3 $ (12 ) Unrealized gains arising during the period 232 (57 ) 175 83 (19 ) 64 Reclassifications of net (gains) losses to: Cost of revenues (109 ) 26 (83 ) (14 ) 3 (11 ) Selling, general and administrative expenses (20 ) 4 (16 ) (3 ) 1 (2 ) Net change 103 (27 ) 76 66 (15 ) 51 Ending balance $ 154 $ (39 ) $ 115 $ 51 $ (12 ) $ 39 Accumulated other comprehensive income (loss): Beginning balance $ (104 ) $ (10 ) $ (114 ) $ (112 ) $ 6 $ (106 ) Other comprehensive income (loss) 209 (25 ) 184 8 (16 ) (8 ) Ending balance $ 105 $ (35 ) $ 70 $ (104 ) $ (10 ) $ (114 )

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	We lease office space and equipment under operating leases, which expire at various dates through the year 2031. Certain leases contain renewal provisions and generally require us to pay utilities, insurance, taxes and other operating expenses. Future minimum payments on our operating leases as of December 31, 2018 were as follows: Operating lease obligation (in millions) 2019 $ 226 2020 197 2021 157 2022 121 2023 90 Thereafter 197 Total minimum lease payments $ 988 Rental expense totaled $282 million, $265 million and $227 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Future minimum payments on our capital leases as of December 31, 2018 were as follows: Capital lease obligation (in millions) 2019 $ 17 2020 13 2021 10 2022 8 2023 4 Thereafter 19 Total minimum lease payments 71 Interest (10 ) Present value of minimum lease payments $ 61 We are involved in various claims and legal actions 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. In the opinion of management, the outcome of any existing claims and legal or regulatory proceedings (other than the specific matters described below, if decided adversely) is not expected to have a material adverse effect on our business, financial condition, results of operations and cash flows. In February 2019, we completed our internal investigation focused on whether certain payments relating to Company-owned facilities in India were made improperly and in violation of the FCPA and other applicable laws. During the year ended December 31, 2016, we recorded out-of-period corrections related to $4 million of potentially improper payments between 2009 and 2016 that had been previously capitalized when they should have been expensed. These out-of-period corrections were not material to any previously issued financial statements. There were no adjustments recorded during 2018 and 2017 related to the amounts then under investigation. On February 15, 2019, we announced a resolution of the previously disclosed investigations by the DOJ and SEC into the matters that were the subject of our internal investigation. The resolution required the Company to pay approximately $28 million to the DOJ and SEC, an amount consistent with the FCPA Accrual. 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. In an order dated February 3, 2017, the United States District Court for the District of New Jersey consolidated the three putative securities class actions into a single action and appointed lead plaintiffs and lead counsel. On April 7, 2017, the lead plaintiffs filed a consolidated amended complaint on behalf of a putative class of stockholders 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, and the motion to dismiss was fully briefed as of September 5, 2017. On August 8, 2018, the Court 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 petition to the Third Circuit. On October 29, 2018, we filed a petition for permission to appeal pursuant to 28 U.S.C. 1292(b) with the United States Court of Appeals for the Third Circuit. Plaintiffs filed their opposition to the petition on November 8, 2018. On November 13, 2018, we filed a motion for leave to file a reply in support of our petition, and a proposed reply. On November 21, 2018, plaintiffs filed an opposition to our motion for leave to file a reply. The parties are now awaiting a decision from the Third Circuit on the petition. 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. On January 24, 2017, the New Jersey Superior Court, Bergen County, consolidated the three putative shareholder derivative actions filed in that court into a single action and appointed lead plaintiff and lead counsel. 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, a fourth putative shareholder derivative complaint asserting similar claims was filed in the United States District Court for the District of New Jersey, naming us and certain of our then current directors as defendants. On April 5, 2017, the United States District Court for the District of New Jersey entered an order staying all proceedings pending a final, non-appealable ruling on the then anticipated motion to dismiss the consolidated putative securities class action. On April 7, 2017, a fifth putative shareholder derivative complaint was filed in the United States District Court for the District of New Jersey, naming us, certain of our then current 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, but also adds a claim for violations of Section 10(b) of the Exchange Act against the individual defendants. On May 10, 2017, a sixth putative shareholder derivative complaint was filed in the United States District Court for the District of New Jersey, naming us, certain of our then current 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, but also adds a claim for violations of Section 14(a) of the Exchange Act against the individual defendants. In an order dated June 20, 2017, the United States District Court for the District of New Jersey consolidated the three putative shareholder derivative actions filed in that court 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, plaintiffs filed a consolidated verified derivative complaint in the consolidated District Court action. All of the putative shareholder derivative complaints allege among other things that certain of our public disclosures were false and misleading by failing to disclose that payments allegedly in violation of the FCPA had been made and by asserting that management had determined that our internal controls were effective. The plaintiffs seek awards of compensatory damages and restitution to the Company as a result of the alleged violations and their costs and attorneys’ fees, experts’ fees, and other litigation expenses, among other relief. 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 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, 2018. We have maintained directors and officers insurance, from which a portion of the indemnification and expense advancement obligations and costs related to the putative securities class action complaints may be recoverable, and have recorded an insurance receivable of $4 million as of December 31, 2018. 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 customers’ business and provide benefits that are difficult to quantify. Any failure in a customer’s systems or our failure to meet our contractual obligations to our customers, including any breach involving a customer’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 to be available on reasonable terms or will be available in sufficient amounts to cover one or more large claims, or that the insurer will not disclaim coverage as to any future claim. The successful assertion of one or more large claims against us that exceed or are not covered by our insurance coverage or changes in our insurance policies, including premium increases or the imposition of large deductible or co-insurance requirements, could have a material adverse effect on our business, results of operations, financial condition and cash flows. In the normal course of business and in conjunction with certain customer engagements, we have entered into contractual arrangements through which we may be obligated to indemnify customers or other parties with whom we conduct business with respect to certain matters. These arrangements can include provisions whereby we agree to hold the indemnified party and certain of their affiliated entities harmless with respect to third-party claims related to such matters as our breach of certain representations or covenants, our intellectual property infringement, our gross negligence or willful misconduct or certain other claims made against certain parties. Payments by us under any of these arrangements are generally conditioned on the customer making a claim and providing us with full control over the defense and settlement of such claim. It is not possible to determine the maximum potential liability under these indemnification agreements due to the unique facts and circumstances involved in each particular agreement. Historically, we have not made payments under these indemnification agreements and therefore they have not had any impact on our operating results, financial position, or cash flows. However, if events arise requiring us to make payment for indemnification claims under our indemnification obligations in contracts we have entered, such payments could have material impact on our business, results of operations, financial condition and cash flows.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2018
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 $108 million, $91 million and $76 million for the years ended December 31, 2018 , 2017 and 2016 , 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 base compensation, which is matched by an equal contribution by the Company. For these plans, we recognized a contribution expense of $88 million, $86 million and $79 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. 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, 2018 and 2017 , the amount accrued under the gratuity plan was $141 million and $114 million, which is net of fund assets of $136 million and $138 million, respectively. Expense recognized by us was $53 million, $40 million and $41 million for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2018
Share-based Compensation [Abstract]
Stock-Based Compensation Plans	The Company's 2017 Incentive Award Plan (the "2017 Incentive Plan") and the 2004 Employee Stock Purchase Plan (the "Purchase Plan"), as amended in 2013, provide for the issuance of up to 48.8 million (plus any shares underlying outstanding awards that are forfeited under the Company’s Amended and Restated 2009 Incentive Compensation Plan ("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, 2018 , we have 38.7 million and 11.8 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: 2018 2017 2016 (in millions) Cost of revenues $ 62 $ 55 $ 53 Selling, general and administrative expenses 205 166 164 Total stock-based compensation expense $ 267 $ 221 $ 217 Income tax benefit $ 66 $ 101 $ 49 As a result of the adoption of authoritative stock compensation guidance in 2017, we recognized net excess tax benefits upon exercise or vesting of stock-based compensation awards in our income tax provision in the amount of $20 million or $0.03 per share in 2018 and $40 million or $0.07 per share in 2017. In 2016 such excess tax benefits were recorded in additional paid in capital. Restricted Stock Units and Performance Stock Units Restricted stock units ("RSUs") vest proportionately in quarterly or annual installments over one to four years . 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, 2018 and changes during the year then ended is presented below: Number of Units (in millions) Weighted Average Grant Date Fair Value (in dollars) Unvested at January 1, 2018 5.2 $ 63.80 Granted 2.8 74.94 Vested (2.5 ) 64.05 Forfeited (0.5 ) 65.93 Unvested at December 31, 2018 5.0 $ 69.64 As of December 31, 2018 , $288 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 2 years . The total vesting date fair value of vested RSUs was $194 million , $169 million and $138 million for the years ended December 31, 2018, 2017 and 2016, respectively. The weighted-average grant date fair value of RSUs granted in 2018, 2017 and 2016 was $74.94 , $67.56 and $55.55 , respectively. We granted performance stock units ("PSUs") that vest over periods ranging from one to three years to employees, including our executive officers. The vesting of PSUs is contingent on both meeting certain financial performance targets and continued service. 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. A summary of the activity for PSUs granted under our stock-based compensation plans as of December 31, 2018 and changes during the year then ended is presented below. The presentation reflects the number of PSUs at the maximum performance milestones. Number of Units (in millions) Weighted Average Grant Date Fair Value (in dollars) Unvested at January 1, 2018 2.7 $ 59.15 Granted 1.8 81.98 Vested (0.7 ) 55.87 Forfeited (0.2 ) 69.86 Reduction due to the achievement of lower than maximum performance milestones (0.3 ) 60.31 Unvested at December 31, 2018 3.3 $ 71.59 As of December 31, 2018 , $67 million of total remaining unrecognized stock-based compensation cost related to PSUs is expected to be recognized over the weighted-average remaining requisite service period of 1 year . The total vesting date fair value of vested PSUs was $53 million , $60 million and $57 million for the years ended December 31, 2018, 2017 and 2016, respectively. The weighted-average grant date fair value of PSUs granted in 2018, 2017 and 2016 was $81.98 , $60.77 and $55.08 , respectively. 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 fair value of RSUs and PSUs is determined based on the number of stock units granted and the quoted price of our stock at date of grant. Stock Options and Purchase Plan Stock options granted to employees under our plans vest proportionally over four years, unless specified otherwise, and have an exercise price equal to the fair market value of the common stock on the date of grant. Grants to non-employee directors vest proportionally over two years. Stock-based compensation expense relating to stock options is recognized on a straight-line basis over the requisite service period. As of December 31, 2018 , there were 0.2 million stock options outstanding and no remaining unrecognized stock-based compensation cost. The total intrinsic value of options exercised was $29 million, $78 million and $74 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. 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, 2018 , 2017 , and 2016 based upon the following assumptions and were as follows: 2018 2017 2016 Dividend yield 1.0 % 1.0 % 0.0 % Weighted average volatility factor 21.0 % 24.3 % 26.5 % Weighted average expected life (in years) 0.25 0.25 0.25 Weighted average risk-free interest rate 1.9 % 0.9 % 0.4 % Weighted average grant date fair value $ 10.87 $ 9.23 $ 8.74 During the year ended December 31, 2018 , we issued 2.7 million shares of Class A common stock under the Purchase Plan with a total fair value of approximately $29 million.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Brackett B. Denniston, III was the Interim General Counsel and an executive officer of the Company from December 2016 until May 15, 2017, during which period Mr. Denniston was also a Senior Counsel at the law firm of Goodwin Procter LLP ("Goodwin"). During the years ended December 31, 2017 and December 31, 2016, Goodwin performed legal services for the Company for which it earned approximately $4 million and $2 million , respectively. For such periods, the provision of legal services from Goodwin was reviewed and approved by our Audit Committee. During the year ended December 31, 2018, Goodwin was not a related party of the Company. In 2018, we provided $100 million of initial funding to the Cognizant U.S. Foundation, which is focused on science, technology, engineering and math education in the United States. 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 during 2018.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
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 and logistics, travel and hospitality, and energy and utilities operating segments; and • Communications, Media and Technology, which includes our communications and media operating segment and our technology operating segment. Our sales managers, account executives, account managers and project teams 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. In 2018, we made changes to the internal measurement of segment operating profits for the purpose of evaluating segment performance and resource allocation. The primary reason for the changes was to charge to our business segments costs that are directly managed and controlled by them. Specifically, segment operating profit now includes the stock-based compensation expense of sales managers, account executives, account managers and project teams, which was previously included in "unallocated costs." In addition, we have changed the methodology of allocating costs to our business segments for the use of our global delivery centers and infrastructure from a fixed per employee charge to a variable per employee charge that differs depending on location and assets deployed. We have reported our 2018 segment operating profits using the new allocation methodology and have restated the 2017 results to conform to the new methodology. It is impracticable for us to restate our 2016 segment operating results as the detailed information required for the allocation of such costs to the segments is not reasonably available. 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 selling, general and administrative expenses, excess or shortfall of incentive compensation for delivery personnel as compared to target, costs related to our realignment program, 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 separately disclosed as “unallocated costs” and adjusted against our total income from operations. Additionally, management has determined that it is not practical to allocate identifiable assets by segment, since such assets are used interchangeably among the segments. Revenues from external customers and segment operating profit, before unallocated costs, by reportable segment were as follows: 2018 (1) 2017 2016 (2) (in millions) Revenues: Financial Services $ 5,845 $ 5,636 $ 5,366 Healthcare 4,668 4,263 3,871 Products and Resources 3,415 3,040 2,660 Communications, Media and Technology 2,197 1,871 1,590 Total revenues $ 16,125 $ 14,810 $ 13,487 Segment Operating Profit: Financial Services $ 1,757 $ 1,771 $ 1,707 Healthcare 1,431 1,301 1,153 Products and Resources 1,043 923 851 Communications, Media and Technology 700 601 488 Total segment operating profit 4,931 4,596 4,199 Less: unallocated costs 2,130 2,115 1,910 Income from operations $ 2,801 $ 2,481 $ 2,289 _________________ (1) Results for 2018 are presented under the New Revenue Standard, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting policies. See Note 3 for additional information. (2) As described above, in 2018 we made changes to the internal measurement of segment operating profits. While we have restated the 2017 results to conform to the new methodology, it is impracticable for us to restate our 2016 segment operating results as the detailed information required for the allocation of such costs to the segments is not reasonably available. Geographic Area Information Revenues and long-lived assets, by geographic area, were as follows: 2018 2017 2016 (in millions) Revenues: (1) North America (2) $ 12,293 $ 11,450 $ 10,546 United Kingdom 1,274 1,150 1,176 Rest of Europe 1,563 1,248 969 Europe - Total 2,837 2,398 2,145 Rest of World (3) 995 962 796 Total $ 16,125 $ 14,810 $ 13,487 2018 2017 2016 (in millions) Long-lived Assets: (4) North America (2) $ 436 $ 360 $ 279 Europe 105 63 52 Rest of World (3)(5) 853 901 980 Total $ 1,394 $ 1,324 $ 1,311 _________________ (1) Revenues are attributed to regions based upon customer location. (2) Substantially all relates to the United States. (3) Includes our operations in Asia Pacific, the Middle East and Latin America. (4) Long-lived assets include property and equipment, net of accumulated depreciation and amortization. (5) Substantially all of these long-lived assets relate to our operations in India.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Data [Abstract]
Quarterly Financial Data (Unaudited)	d quarterly results for the two years ended December 31, 2018 are as follows: Three Months Ended 2018 (1) March 31 June 30 September 30 December 31 Full Year (in millions, except per share data) Revenues $ 3,912 $ 4,006 $ 4,078 $ 4,129 $ 16,125 Cost of revenues (exclusive of depreciation and amortization expense shown separately below) 2,401 2,417 2,480 2,540 9,838 Selling, general and administrative expenses 711 805 734 776 3,026 Depreciation and amortization expense 107 114 119 120 460 Income from operations 693 670 745 693 2,801 Net income 520 456 477 648 2,101 Basic earnings per share $ 0.89 $ 0.78 $ 0.82 $ 1.12 $ 3.61 Diluted earnings per share $ 0.88 $ 0.78 $ 0.82 $ 1.12 $ 3.60 Three Months Ended 2017 March 31 June 30 September 30 December 31 Full Year (in millions, except per share data) Revenues $ 3,546 $ 3,670 $ 3,766 $ 3,828 $ 14,810 Cost of revenues (exclusive of depreciation and amortization expense shown separately below) 2,194 2,261 2,337 2,360 9,152 Selling, general and administrative expenses 686 709 674 700 2,769 Depreciation and amortization expense 96 94 107 111 408 Income from operations 570 606 648 657 2,481 Net income (loss) (2) 557 470 495 (18 ) 1,504 Basic earnings (losses) per share (3) $ 0.92 $ 0.80 $ 0.84 $ (0.03 ) $ 2.54 Diluted earnings (losses) per share (3) $ 0.92 $ 0.80 $ 0.84 $ (0.03 ) $ 2.53 _________________ (1) Results for 2018 are presented under the New Revenue Standard, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting policies. See Note 3 for additional information. (2) The net loss for the quarter ended December 31, 2017, includes the one-time provisional incremental income tax expense relating to the Tax Reform Act. See Note 11 . (3) The sum of the quarterly basic and diluted earnings (losses) per share for each of the four quarters may not equal the earnings (losses) per share for the year due to rounding.

Valuation And Qualifying Accoun

Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation And Qualifying Accounts	Valuation and Qualifying Accounts For the Years Ended December 31, 2018 , 2017 and 2016 (in millions) Description Balance at Beginning of Period Charged to Costs and Expenses Charged to Other Accounts Deductions /Other Balance at End of Period (in millions) Trade accounts receivable allowance for doubtful accounts: 2018 $ 65 $ 13 $ — $ — $ 78 2017 $ 48 $ 15 $ 3 $ 1 $ 65 2016 $ 39 $ 12 $ — $ 3 $ 48 Warranty accrual: 2018 $ 30 $ 32 $ — $ 30 $ 32 2017 $ 26 $ 30 $ — $ 26 $ 30 2016 $ 24 $ 28 $ — $ 26 $ 26 Valuation allowance—deferred income tax assets: 2018 $ 10 $ 1 $ — $ — $ 11 2017 $ 10 $ — $ — $ — $ 10 2016 $ 10 $ — $ — $ — $ 10

Subsequent Events (Notes)

Subsequent Events (Notes)	12 Months Ended
	Dec. 31, 2018
Subsequent Event [Line Items]
Subsequent Events [Text Block]	Dividend On February 4, 2019, our Board of Directors approved the Company's declaration of a $0.20 per share dividend with a record date of February 21, 2019 and a payment date of February 28, 2019.

Business Description and Summ_2

Business Description and Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2018
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 generally accepted accounting principles in the United States of America ("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 and 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. We have classified and accounted for our marketable debt securities as either available-for-sale or held-to-maturity. After consideration of our risk versus reward objectives, as well as our liquidity requirements, we may sell our available-for-sale securities prior to their stated maturities. We classify these marketable securities with maturities at the date of purchase beyond 90 days as short-term investments based on their highly liquid nature and because such marketable securities represent an investment of cash that is available for current operations. 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. Available-for-sale securities are reported at fair value with changes in unrealized gains and losses recorded as a separate component of accumulated other comprehensive income (loss) until realized. We determine the cost of the securities sold based on the specific identification method. Held-to-maturity securities are reported at amortized cost. Time deposits with financial institutions are valued at cost, which approximates fair value. Interest and amortization of premiums and discounts for debt securities are included in interest income. On a quarterly basis, we evaluate our available-for-sale and held-to-maturity investments for possible other-than-temporary impairment by reviewing quantitative and qualitative factors. If we do not intend to sell the security or it is not more likely than not that we will be required to sell the security before recovery of our amortized cost, we evaluate quantitative and qualitative criteria to determine whether we expect to recover the amortized cost basis of the security. If we do not expect to recover the entire amortized cost basis of the security, we consider the security to be other-than-temporarily impaired and we record the difference between the security’s amortized cost basis and its recoverable amount in earnings and the difference between the security’s recoverable amount and fair value in other comprehensive income. If we intend to sell the security or it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis, the security is also considered other-than-temporarily impaired and we recognize the entire difference between the security’s amortized cost basis and its fair value in earnings.
Allowance For Doubtful Accounts	Allowance for Doubtful Accounts. We maintain an allowance for doubtful accounts to provide for the estimated amount of receivables that may not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience, the age of outstanding receivables and other applicable factors. We evaluate the collectability of our trade accounts receivable on an on-going basis and write off accounts when they are deemed to be uncollectable.
Short-Term Financial Assets And Liabilities	Short-term Financial Assets and Liabilities. Cash and certain cash equivalents, 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 improvement. In India, leasehold land is leased by us from the government of India with lease terms ranging up to 99 years. Lease payments are made at the inception of the lease agreement and amortized over the lease term. Maintenance and repairs are expensed as incurred, while renewals and betterments are capitalized. Deposits paid towards acquisition of long-lived assets and the cost of assets not put in use before the balance sheet date are disclosed under the caption "Capital work-in-progress" in Note 7 .
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 customers, 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 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 .
Equity Method Investments And Cost 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 carrying value. The Company's proportionate share of the net income or loss of the investee is recorded in the caption "Income from equity method investments" on our consolidated statements of operations. The investment balance is increased or decreased for cash contributions or distributions to or from these investees.
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 intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. We recognize an impairment loss when the sum of undiscounted expected future cash flows is less than the carrying amount of such assets. The impairment loss is determined as the amount by which the carrying amount of the asset exceeds the fair value of the asset. 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 trading plan adopted pursuant to Rule 10b5-1 of the Exchange Act, or in private transactions, including through accelerated stock repurchase agreements ("ASRs") entered into with financial institutions, in accordance with applicable 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 customers 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 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. 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 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 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. Prior to the adoption of ASC 606 on January 1, 2018, revenues were earned and recognized when all of the following criteria were met: evidence of an arrangement existed, the price was fixed or determinable, the services had been rendered and collectability was reasonably assured. Contingent or incentive revenues were recognized when the contingency was satisfied and we concluded the amounts were earned. Volume discounts were recorded as a reduction of revenues as services were provided. Revenues also included the reimbursement of out-of-pocket expenses. Trade Receivables, 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 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. The noncurrent portion of deferred revenue is included in "Other noncurrent liabilities" in our consolidated statements of financial position. Our contract assets and 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 deferred revenues primarily results from the timing difference between our performance obligations and the customer’s payment. We receive payments from customers based on the terms established in our contracts, which vary by contract type. Allowance for Doubtful Accounts. We maintain an allowance for doubtful accounts to provide for the estimated amount of receivables that may not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience, the age of outstanding receivables and other applicable factors. We evaluate the collectability of our trade accounts receivable on an on-going basis and write off accounts when they are deemed to be uncollectable. Cost to Fulfill. Recurring operating costs for contracts with customers are recognized as incurred. Certain eligible, nonrecurring costs incurred in the initial phases of our contracts (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 to evaluate 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.
Trade and Other Accounts Receivable, Policy [Policy Text Block]	Trade Receivables, 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 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. The noncurrent portion of deferred revenue is included in "Other noncurrent liabilities" in our consolidated statements of financial position. Our contract assets and 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 deferred revenues primarily results from the timing difference between our performance obligations and the customer’s payment. We receive payments from customers based on the terms established in our contracts, which vary by contract type.
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.
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 from functional currencies at current exchange rates while revenues and expenses are translated from functional currencies 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 subsidiary’s functional currency. The subsidiary's functional currency is the currency of the primary economic environment in which the subsidiary 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 subsidiary at historical exchange rates while monetary assets and liabilities are remeasured to the functional currency of the subsidiary 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 of foreign exchange forward 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 derivative financial 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. 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. Beginning in 2017, the differences between actual tax benefits realized on employee stock awards and estimated tax benefits at date of grant are adjusted to our provision for income taxes upon vesting or exercise of the stock award. 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 ("EPS"). Basic EPS excludes dilution and 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 2018 , 2017 and 2016 from our diluted EPS calculation. We include performance stock unit awards in the dilutive potential common shares when they become contingently issuable per the authoritative guidance and exclude the awards 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 January 1, 2018 Modified Retrospective 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. See Note 3 for the impact of adoption of this standard. November 2016 Statement of Cash Flows January 1, 2018 Retrospective This update requires restricted cash to be included with cash and cash equivalents when reconciling the beginning and ending amounts on the statement of cash flows. It also requires a reconciliation of such totals to the amounts on the statement of financial position and disclosure as to the nature of the restrictions. There were no restricted cash balances as of December 31, 2018. The adoption of this update had no impact on our financial statements for the year ended December 31, 2018. February 2018 January 1, 2018 In the period of adoption This update provides an option for entities to reclassify stranded tax effects caused by the recently-enacted Tax Cuts and Jobs Act ("Tax Reform Act") from accumulated other comprehensive income to retained earnings. We have early adopted this update as of January 1, 2018. The adoption resulted in a decrease of $1 million in accumulated other comprehensive income and a corresponding increase of $1 million to opening retained earnings. New Accounting Pronouncements Date Issued and Topic Effective Date Description Impact February 2016 January 1, 2019 The new standard replaces the existing guidance on leases and requires the lessee to recognize a right-of-use ("ROU") asset and a lease liability for all leases with lease terms equal to or greater than twelve months. For finance leases, the lessee would recognize interest expense and amortization of the ROU asset, and for operating leases, the lessee would recognize 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 retrospective to the beginning of the period of adoption through a cumulative-effect adjustment (the effective date method). We expect to adopt the new standard on January 1, 2019 using the effective date method. Upon adoption, we expect to recognize additional lease assets and liabilities of approximately $750 million to $800 million. We intend to elect the package of practical expedients that permits us not to reassess prior conclusions related to contracts containing leases, lease classification and initial direct costs. We do not expect to elect the use of the hindsight practical expedient. The new standard also provides practical expedients for an entity’s ongoing accounting. We expect to elect the short-term lease recognition exemption. This means, for those leases that qualify, we will not recognize ROU assets or lease liabilities in transition or on an ongoing basis. We also expect to elect the practical expedient that permits us not to separate lease and non-lease components for all of our leases. March 2017 January 1, 2019 This update shortens the amortization period for certain callable debt securities held at a premium to the earliest call date. The amendments do not require an accounting change for securities held at a discount. Upon adoption, entities will be required to use a modified retrospective transition with the cumulative effect adjustment recognized to retained earnings as of the beginning of the period of adoption. We do not expect the adoption of this update to have a material impact on our financial statements. August 2018 Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement ("CCA") that is a Service Contract January 1, 2020 This update aligns the accounting for costs incurred to implement a CCA that is a service arrangement with the guidance on capitalizing costs associated with developing or obtaining internal-use software. The update clarifies that a customer should capitalize certain implementation costs and subsequently amortize such costs over the term of the hosting arrangement as operating expenses. We do not expect the adoption of this update to have a material impact on our financial statements.

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2018
Revenues [Abstract]
Schedule of New Accounting Pronouncements	The following tables compare the financial statement line items materially affected by the adoption of the New Revenue Standard as of and for the year ended December 31, 2018 to the pro-forma amounts had the previous guidance been in effect ("Pro-forma Amounts"): December 31, 2018 As Reported Pro-forma Amounts Impacts of the New Revenue Standard (in millions) Assets: Trade accounts receivable, net (1), (2) $ 3,257 $ 3,115 $ 142 Unbilled accounts receivable (1), (3) — 485 (485 ) Other current assets (2), (3) 909 604 305 Total current assets (38 ) Other noncurrent assets (4) 689 615 74 Total assets $ 36 Liabilities: Deferred revenue, current (2) $ 286 $ 498 $ (212 ) Total current liabilities (212 ) Deferred revenue, noncurrent (2) 62 108 (46 ) Deferred income tax liabilities, net (5) 183 118 65 Total liabilities (193 ) Stockholders’ equity: Retained earnings 11,485 11,256 229 Total stockholders’ equity 229 Total liabilities and stockholders’ equity $ 36 Year Ended December 31, 2018 As Reported Pro-forma Amounts Impacts of the New Revenue Standard (in millions) Revenues (2) $ 16,125 $ 16,029 $ 96 Cost of revenues (4) 9,838 9,876 (38 ) Selling, general and administrative expenses 3,026 3,026 — Depreciation and amortization expense 460 460 — Income from operations 2,801 2,667 134 Other income (expense), net (4 ) (5 ) 1 Income before provision for income taxes (5) 2,797 2,662 135 Provision for income taxes (698 ) (671 ) (27 ) Income (loss) from equity method investment 2 2 — Net income $ 2,101 $ 1,993 $ 108 Basic earnings per share $ 3.61 $ 3.42 $ 0.19 Diluted earnings per share $ 3.60 $ 3.41 $ 0.19 (1) Reflects the reclassification of balances representing receivables, as defined by the New Revenue Standard, from Unbilled accounts receivable to Trade accounts receivable, net. (2) Reflects the impact of changes in the method used to measure progress on our fixed-price application maintenance, consulting and business process services contracts and the timing of revenue recognition and allocation of purchase price on our software license contracts. (3) Reflects the reclassification of balances representing contract assets, as defined by the New Revenue Standard, from Unbilled accounts receivable to Other current assets. (4) Reflects the impact of a longer period of amortization for costs to fulfill a contract as well as a change in the methodology of assessing the recoverability of such costs. (5) Reflects the income tax impact of the above items.
Capitalized Contract Cost	Costs to Fulfill The following table presents information related to the capitalized costs to fulfill, such as set-up or transition activities, for the year ended December 31, 2018 . 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 statements of operations. Costs to obtain contracts were immaterial for the periods disclosed. Costs to Fulfill (in millions) Balance - January 1, 2018 $ 303 Amortization expense (70 ) Costs capitalized 170 Other (3 ) Balance - December 31, 2018 $ 400
Contract with Customer, Asset and Liability	Contract Assets (in millions) Balance - January 1, 2018 $ 306 Revenues recognized during the period but not billed 285 Amounts reclassified to accounts receivable (282 ) Other (4 ) Balance - December 31, 2018 $ 305 The table below shows significant movements in the deferred revenue balances (current and noncurrent) for the period disclosed: Deferred Revenue (in millions) Balance - January 1, 2018 $ 431 Amounts billed but not recognized as revenues 204 Revenues recognized related to the opening balance of deferred revenue (284 ) Other (3 ) Balance - December 31, 2018 $ 348 The table below shows significant movements in contract assets: Contract Assets (in millions) Balance - January 1, 2018 $ 306 Revenues recognized during the period but not billed 285 Amounts reclassified to accounts receivable (282 ) Other (4 ) Balance - December 31, 2018 $ 305
Disaggregation of Revenue	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. 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 Rest of 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 (1) $ 3,571 $ 2,553 $ 2,024 $ 1,161 $ 9,309 Outsourcing services (2) 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 (1) Our consulting and technology services include consulting, application development, systems integration, and application testing services as well as software solutions and related services. (2) Our outsourcing services include application maintenance, infrastructure and business process services.

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2018
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The allocation of purchase price to the fair value of the aggregate assets acquired and liabilities assumed was as follows: Fair Value Weighted Average Useful Life (in millions) Cash $ 8 Current assets 47 Property, plant and equipment and other noncurrent assets 19 Non-deductible goodwill 125 Customer relationship intangible assets 147 10.6 years Other intangible assets 4 2.4 years Current liabilities (50 ) Noncurrent liabilities (67 ) Purchase price $ 233 The allocation of purchase price to the fair value of the aggregate assets acquired and liabilities assumed was as follows: Softvision Bolder Others Total Weighted Average Useful Life ( dollars in millions) Cash $ 4 $ 7 $ 4 $ 15 Current assets 54 32 15 101 Property, plant and equipment and other noncurrent assets 7 7 1 15 Non-deductible goodwill 385 335 76 796 Customer relationship intangible assets 133 113 30 276 10.3 years Other intangible assets 9 17 1 27 3.7 years Trademark — 9 — 9 Indefinite Current liabilities (47 ) (11 ) (9 ) (67 ) Noncurrent liabilities (4 ) (37 ) (9 ) (50 ) Purchase price $ 541 $ 472 $ 109 $ 1,122 The allocation of purchase price to the fair value of the aggregate assets acquired and liabilities assumed was as follows: Fair Value Weighted Average Useful Life (in millions) Cash $ 17 Current assets 84 Property, plant and equipment and other noncurrent assets 53 Non-deductible goodwill 157 Customer relationship intangible assets 199 6.6 years Other intangible assets 1 3.3 years Current liabilities (173 ) Noncurrent liabilities (51 ) Purchase price $ 287

Realignment Charges (Tables)

Realignment Charges (Tables)	12 Months Ended
	Dec. 31, 2018
Realignment Charges [Abstract]
Realignment Charges	Years Ended December 31, 2018 2017 (in millions) Severance costs $ 18 $ 53 Advisory fees — 18 Lease termination costs 1 1 Total realignment costs $ 19 $ 72

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2018
Investment [Line Items]
Marketable Securities [Table Text Block]	Our investments were as follows as of December 31: 2018 2017 (in millions) Short-term investments: Equity investment securities $ 25 $ 25 Available-for-sale investment securities 1,760 1,972 Held-to-maturity investment securities 1,065 745 Time deposits 500 (1) 389 Total short-term investments $ 3,350 $ 3,131 Long-term investments: Equity and cost method investments $ 74 $ 74 Held-to-maturity investment securities 6 161 Total long-term investments $ 80 $ 235
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: 2018 2017 2016 (in millions) Proceeds from sales of available-for-sale investment securities $ 1,285 $ 2,922 $ 3,541 Gross gains $ — $ 1 $ 5 Gross losses (4 ) (3 ) (4 ) Net realized (losses) gains on sales of available-for-sale investment securities $ (4 ) $ (2 ) $ 1
Available-for-sale Securities [Member]
Investment [Line Items]
Unrealized Gain (Loss) on Investments [Table Text Block]	The amortized cost, gross unrealized gains and losses and fair value of our available-for-sale investment securities were as follows at December 31: 2018 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in millions) U.S. Treasury and agency debt securities $ 630 $ 1 $ (6 ) $ 625 Corporate and other debt securities 420 — (4 ) 416 Certificates of deposit and commercial paper 296 — — 296 Asset-backed securities 336 — (2 ) 334 Municipal debt securities 90 — (1 ) 89 Total available-for-sale investment securities $ 1,772 $ 1 $ (13 ) $ 1,760 2017 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in millions) U.S. Treasury and agency debt securities $ 667 $ — $ (6 ) $ 661 Corporate and other debt securities 439 — (2 ) 437 Certificates of deposit and commercial paper 450 — — 450 Asset-backed securities 297 — (2 ) 295 Municipal debt securities 130 — (1 ) 129 Total available-for-sale investment securities $ 1,983 $ — $ (11 ) $ 1,972
Schedule of Temporary Impairment Losses, Investments [Table Text Block]	The fair value and related unrealized losses of our available-for-sale investment securities in a continuous unrealized loss position for less than 12 months and for 12 months or longer were as follows as of December 31: 2018 Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in millions) U.S. Treasury and agency debt securities $ 84 $ — $ 446 $ (6 ) $ 530 $ (6 ) Corporate and other debt securities 108 (1 ) 254 (3 ) 362 (4 ) Certificates of deposit and commercial paper 295 — — — 295 — Asset-backed securities 93 — 179 (2 ) 272 (2 ) Municipal debt securities 17 — 64 (1 ) 81 (1 ) Total $ 597 $ (1 ) $ 943 $ (12 ) $ 1,540 $ (13 ) 2017 Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in millions) U.S. Treasury and agency debt securities $ 519 $ (4 ) $ 124 $ (2 ) $ 643 $ (6 ) Corporate and other debt securities 297 (1 ) 126 (1 ) 423 (2 ) Certificates of deposit and commercial paper 49 — — — 49 — Asset-backed securities 193 (1 ) 94 (1 ) 287 (2 ) Municipal debt securities 107 (1 ) 18 — 125 (1 ) Total $ 1,165 $ (7 ) $ 362 $ (4 ) $ 1,527 $ (11 )
Investments Classified by Contractual Maturity Date [Table Text Block]	The contractual maturities of our fixed income available-for-sale investment securities as of December 31, 2018 are set forth in the following table: Amortized Cost Fair Value (in millions) Due within one year $ 569 $ 567 Due after one year up to two years 544 537 Due after two years up to three years 267 265 Due after three years 56 57 Asset-backed securities 336 334 Total available-for-sale investment securities $ 1,772 $ 1,760
Held-to-maturity Securities [Member]
Investment [Line Items]
Unrealized Gain (Loss) on Investments [Table Text Block]	2018 Amortized Unrealized Unrealized Fair (in millions) Short-term investments: Corporate and other debt securities $ 546 $ — $ — $ 546 Commercial paper 519 — (1 ) 518 Total short-term held-to-maturity investments 1,065 — (1 ) 1,064 Long-term investments: Corporate and other debt securities 6 — — 6 Total held-to-maturity investment securities $ 1,071 $ — $ (1 ) $ 1,070 2017 Amortized Unrealized Unrealized Fair (in millions) Short-term investments: Corporate and other debt securities $ 346 $ — $ (1 ) $ 345 Commercial paper 399 — (2 ) 397 Total short-term held-to-maturity investments 745 — (3 ) 742 Long-term investments: Corporate and other debt securities 161 — (1 ) 160 Total held-to-maturity investment securities $ 906 $ — $ (4 ) $ 902
Schedule of Temporary Impairment Losses, Investments [Table Text Block]	The fair value and related unrealized losses of held-to-maturity investment securities in a continuous unrealized loss position for less than 12 months and for 12 months or longer were as follows as of December 31: 2018 Less than 12 Months 12 Months or More Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (in millions) Corporate and other debt securities $ 263 $ — $ 57 $ — $ 320 $ — Commercial paper 268 (1 ) — — 268 (1 ) Total $ 531 $ (1 ) $ 57 $ — $ 588 $ (1 )
Investments Classified by Contractual Maturity Date [Table Text Block]	The contractual maturities of our fixed income held-to-maturity investment securities as of December 31, 2018 are set forth in the following table: Amortized Cost Fair Value (in millions) Due within one year $ 1,065 $ 1,064 Due after one year up to two years 6 6 Total held-to-maturity investment securities $ 1,071 $ 1,070

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment, Net [Abstract]
Schedule of property and equipment	Property and equipment were as follows as of December 31: Estimated Useful Life (Years) 2018 2017 (in millions) Buildings 30 $ 839 $ 836 Computer equipment 3 – 5 412 364 Computer software 3 – 8 721 594 Furniture and equipment 5 – 9 639 511 Land 19 19 Leasehold land lease term 60 63 Capital work-in-progress 156 145 Leasehold improvements Shorter of the lease term or the life of the leased asset 338 308 Sub-total 3,184 2,840 Accumulated depreciation and amortization (1,790 ) (1,516 ) Property and equipment, net $ 1,394 $ 1,324

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, net (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 and 2017 : Segment January 1, 2018 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments December 31, 2018 (in millions) Financial Services $ 265 $ 152 $ (6 ) $ 411 Healthcare 2,106 365 (2 ) 2,469 Products and Resources 240 152 (8 ) 384 Communications, Media and Technology 93 126 (2 ) 217 Total goodwill $ 2,704 $ 795 $ (18 ) $ 3,481 Segment January 1, 2017 Goodwill Additions and Adjustments Foreign Currency Translation Adjustments December 31, 2017 (in millions) Financial Services $ 227 $ 27 $ 11 $ 265 Healthcare 2,089 13 4 2,106 Products and Resources 159 72 9 240 Communications, Media and Technology 79 11 3 93 Total goodwill $ 2,554 $ 123 $ 27 $ 2,704
Schedule of Finite-Lived Intangible Assets	Components of intangible assets were as follows as of December 31: 2018 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (in millions) Customer relationships $ 1,277 $ (398 ) $ 879 $ 1,005 $ (304 ) $ 701 Developed technology 355 (187 ) 168 333 (140 ) 193 Indefinite life trademarks 72 — 72 63 — 63 Other 64 (33 ) 31 51 (27 ) 24 Total intangible assets $ 1,768 $ (618 ) $ 1,150 $ 1,452 $ (471 ) $ 981
Schedule of Indefinite-Lived Intangible Assets	Components of intangible assets were as follows as of December 31: 2018 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (in millions) Customer relationships $ 1,277 $ (398 ) $ 879 $ 1,005 $ (304 ) $ 701 Developed technology 355 (187 ) 168 333 (140 ) 193 Indefinite life trademarks 72 — 72 63 — 63 Other 64 (33 ) 31 51 (27 ) 24 Total intangible assets $ 1,768 $ (618 ) $ 1,150 $ 1,452 $ (471 ) $ 981
Schedule Of Estimated Amortization Expense	Estimated amortization related to our existing intangible assets for the next five years is as follows: Year Amount (in millions) 2019 $ 167 2020 158 2021 153 2022 137 2023 83

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
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: 2018 2017 (in millions) Compensation and benefits $ 1,216 $ 1,272 Customer volume and other incentives 323 289 Derivative financial instruments 25 5 FCPA Accrual 28 — Income taxes 162 48 Professional fees 110 100 Travel and entertainment 34 32 Other 369 325 Total accrued expenses and other current liabilities $ 2,267 $ 2,071

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of short-term debt	The following summarizes our short-term debt balances as of December 31: 2018 2017 Amount Weighted Average Interest Rate Amount Weighted Average Interest Rate (in millions) (in millions) Notes outstanding under revolving credit facility $ — not applicable $ 75 4.5 % Term loan - current maturities 9 3.3 % 100 2.4 % Total short-term debt $ 9 $ 175
Schedule of long-term debt	The following summarizes our long-term debt balances as of December 31: 2018 2017 (in millions) Term loan $ 750 $ 800 Less: Current maturities (9 ) (100 ) Deferred financing costs (5 ) (2 ) Long-term debt, net of current maturities $ 736 $ 698
Schedule of debt maturities	The following represents the schedule of maturities of our term loan: Year Amounts (in millions) 2019 $ 9 2020 38 2021 38 2022 38 2023 627 $ 750

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
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: 2018 2017 2016 (in millions) United States $ 947 $ 810 $ 752 Foreign 1,850 1,845 1,605 Income before provision for income taxes $ 2,797 $ 2,655 $ 2,357
Schedule Of Components Of Provision For Income Taxes	The provision for income taxes consisted of the following components for the years ended December 31: 2018 2017 2016 (in millions) Current: Federal and state $ 241 $ 767 $ 544 Foreign 449 262 352 Total current provision 690 1,029 896 Deferred: Federal and state 1 102 (44 ) Foreign 7 22 (47 ) Total deferred provision (benefit) 8 124 (91 ) Total provision for income taxes $ 698 $ 1,153 $ 805
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: 2018 % 2017 % 2016 % (Dollars in millions) Tax expense, at U.S. federal statutory rate $ 587 21.0 $ 929 35.0 $ 825 35.0 State and local income taxes, net of federal benefit 56 2.0 39 1.5 42 1.8 Non-taxable income for Indian tax purposes (146 ) (5.2 ) (216 ) (8.2 ) (203 ) (8.6 ) Rate differential on foreign earnings 206 7.4 (76 ) (2.9 ) (55 ) (2.3 ) Net impact related to the implementation of the Tax Reform Act (5 ) (0.2 ) 617 23.2 — — India Cash Remittance — — — — 238 10.1 Recognition of previously unrecognized income tax benefits related to uncertain tax positions (12 ) (0.4 ) (73 ) (2.7 ) (16 ) (0.7 ) Credits and other incentives (19 ) (0.7 ) (37 ) (1.4 ) (57 ) (2.4 ) Other 31 1.1 (30 ) (1.1 ) 31 1.3 Total provision for income taxes $ 698 25.0 $ 1,153 43.4 $ 805 34.2
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: 2018 2017 (in millions) Deferred income tax assets: Net operating losses $ 13 $ 15 Revenue recognition 51 55 Compensation and benefits 133 125 Stock-based compensation 17 14 Minimum alternative tax ("MAT") and other credits 340 369 Other accrued expenses 60 22 614 600 Less: valuation allowance (11 ) (10 ) Deferred income tax assets, net 603 590 Deferred income tax liabilities: Depreciation and amortization 256 209 Deferred costs 79 65 Other 9 44 Deferred income tax liabilities 344 318 Net deferred income tax assets $ 259 $ 272
Summary Of Changes in Unrecognized Tax Benefits	Changes in unrecognized income tax benefits were as follows for the years ended December 31: 2018 2017 2016 (in millions) Balance, beginning of year $ 97 $ 151 $ 139 Additions based on tax positions related to the current year 8 17 11 Additions for tax positions of prior years 19 2 19 Additions for tax positions of acquired subsidiaries 6 — — Reductions for tax positions due to lapse of statutes of limitations (12 ) (41 ) (15 ) Reductions for tax positions of prior years — (32 ) (1 ) Settlements — — — Foreign currency exchange movement (1 ) — (2 ) Balance, end of year $ 117 $ 97 $ 151

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
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: 2018 2017 Designation of Derivatives Location on Statement of Financial Position Assets Liabilities Assets Liabilities (in millions) Foreign exchange forward contracts - Designated as cash flow hedging instruments Other current assets $ 11 $ — $ 134 $ — Other noncurrent assets 15 — 20 — Accrued expenses and other current liabilities — 21 — — Other noncurrent liabilities — 9 — — Total 26 30 154 — Foreign exchange forward contracts - Not designated as cash flow hedging instruments Other current assets 1 — — — Accrued expenses and other current liabilities — 4 — 5 Total 1 4 — 5 Total $ 27 $ 34 $ 154 $ 5
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 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: 2018 2017 (in millions) 2018 $ — $ 1,185 2019 1,388 720 2020 780 — Total notional value of contracts outstanding $ 2,168 $ 1,905 Net unrealized (losses) gains included in accumulated other comprehensive income (loss), net of taxes $ (3 ) $ 115
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 and losses on our cash flow hedges for the year ended December 31: Change in Derivative Gains/Losses Recognized in Accumulated Other Comprehensive Income (Loss) (effective portion) Location of Net Derivative Gains Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion) Net Gains Reclassified from Accumulated Other Comprehensive Income (Loss) into Income (effective portion) 2018 2017 2018 2017 (in millions) Foreign exchange forward contracts - Designated as cash flow hedging instruments $ (87 ) $ 232 Cost of revenues $ 61 $ 109 Selling, general and administrative expenses 10 20 Total $ 71 $ 129
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: 2018 2017 Notional Market Value Notional Market Value (in millions) Contracts outstanding $ 507 $ (3 ) $ 255 $ (5 ) The following table provides information on the location and amounts of realized and unrealized pre-tax gains and losses on our other derivative financial instruments for the year ended December 31: Location of Net Gains (Losses) on Derivative Instruments Amount of Net Gains (Losses) on Derivative Instruments 2018 2017 (in millions) Foreign exchange forward contracts - Not designated as hedging instruments Foreign currency exchange gains (losses), net $ 31 $ (23 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 : Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 103 $ — $ — $ 103 Bank deposits — 32 — 32 Certificates of deposit and commercial paper — 68 — 68 Total cash equivalents 103 100 — 203 Short-term investments: Time deposits (1) — 500 — 500 Available-for-sale investment securities: U.S. Treasury and agency debt securities 570 55 — 625 Corporate and other debt securities — 416 — 416 Certificates of deposit and commercial paper — 296 — 296 Asset-backed securities — 334 — 334 Municipal debt securities — 89 — 89 Total available-for-sale investment securities 570 1,190 — 1,760 Held-to-maturity investment securities: Corporate and other debt securities — 546 — 546 Commercial paper — 518 — 518 Total short-term held-to-maturity investment securities — 1,064 — 1,064 Total short-term investments (2) 570 2,754 — 3,324 Long-term investments: Held-to-maturity investment securities: Corporate and other debt securities — 6 — 6 Total long-term held-to-maturity investment securities — 6 — 6 Total long-term investments (3) — 6 — 6 Derivative financial instruments - foreign exchange forward contracts: Other current assets — 12 — 12 Accrued expenses and other current liabilities — (25 ) — (25 ) Other noncurrent assets — 15 — 15 Other noncurrent liabilities — (9 ) — (9 ) Total $ 673 $ 2,853 $ — $ 3,526 ________________ (1) Includes $423 million in restricted time deposits. See Note 11 . (2) Excludes an equity security invested in a mutual fund valued at $25 million based on the NAV of the fund. (3) Excludes equity and cost method investments of $74 million at December 31, 2018. The following table summarizes our financial assets and (liabilities) measured at fair value on a recurring basis as of December 31, 2017 : Level 1 Level 2 Level 3 Total (in millions) Cash equivalents: Money market funds $ 334 $ — $ — $ 334 Bank deposits — 80 — 80 Commercial paper — 386 — 386 Total cash equivalents 334 466 — 800 Short-term investments: Time deposits — 389 — 389 Available-for-sale investment securities: U.S. Treasury and agency debt securities 585 76 — 661 Corporate and other debt securities — 437 — 437 Certificates of deposit and commercial paper — 450 — 450 Asset-backed securities — 295 — 295 Municipal debt securities — 129 — 129 Total available-for-sale investment securities 585 1,387 — 1,972 Held-to-maturity investment securities: Corporate and other debt securities — 345 — 345 Commercial Paper — 397 — 397 Total short-term held-to-maturity investment securities — 742 — 742 Total short-term investments (1) 585 2,518 — 3,103 Long-term investments: Held-to-maturity investment securities: Corporate and other debt securities — 160 — 160 Total long-term held-to-maturity investment securities — 160 — 160 Total long-term investments (2) — 160 — 160 Derivative financial instruments - foreign exchange forward contracts: Other current assets — 134 — 134 Accrued expenses and other current liabilities — (5 ) — (5 ) Other noncurrent assets — 20 — 20 Total $ 919 $ 3,293 $ — $ 4,212 ________________ (1) Excludes an equity security invested in a mutual fund valued at $25 million based on the NAV of the fund. (2) Excludes equity and cost method investments of $74 million at December 31, 2017

Stockholder's Equity (Tables)

Stockholder's Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Schedule of Share Repurchase Activity [Table Text Block]	The Company’s share repurchase activity was as follows for the years ended December 31: 2018 2017 2016 Shares Amount Shares Amount Shares Amount (in millions) Open-market share repurchases 4 $ 275 — $ — 8 $ 440 ASRs 12 900 28 1,800 — — Share repurchases in connection with stock-based compensation plans 1 86 1 89 1 72 17 $ 1,261 29 $ 1,889 9 $ 512
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, 2018 : 2018 Before Tax Amount Tax Effect Net of Tax Amount (in millions) Foreign currency translation adjustments: Beginning balance $ (38 ) $ — $ (38 ) Change in foreign currency translation adjustments (70 ) 5 (65 ) Ending balance $ (108 ) $ 5 $ (103 ) Unrealized (losses) on available-for-sale investment securities: Beginning balance $ (11 ) $ 4 $ (7 ) Cumulative effect of change in accounting principle (1) — (1 ) (1 ) Net unrealized losses arising during the period (5 ) 2 (3 ) Reclassification of net losses to Other, net 4 (1 ) 3 Net change (1 ) — (1 ) Ending balance $ (12 ) $ 4 $ (8 ) Unrealized gains (losses) on cash flow hedges: Beginning balance $ 154 $ (39 ) $ 115 Unrealized (losses) arising during the period (87 ) 23 (64 ) Reclassifications of net (gains) to: Cost of revenues (61 ) 15 (46 ) Selling, general and administrative expenses (10 ) 2 (8 ) Net change (158 ) 40 (118 ) Ending balance $ (4 ) $ 1 $ (3 ) Accumulated other comprehensive income (loss): Beginning balance $ 105 $ (35 ) $ 70 Other comprehensive income (loss) (229 ) 45 (184 ) Ending balance $ (124 ) $ 10 $ (114 ) (1) Reflects the adoption of accounting standards as described in Note 1 . Changes in "Accumulated other comprehensive income (loss)" by component were as follows for the years ended December 31, 2017 and 2016 : 2017 2016 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Tax Net of Tax (in millions) Foreign currency translation adjustments: Beginning balance $ (149 ) $ — $ (149 ) $ (90 ) $ — $ (90 ) Change in foreign currency translation adjustments 111 — 111 (59 ) — (59 ) Ending balance $ (38 ) $ — $ (38 ) $ (149 ) $ — $ (149 ) Unrealized (losses) on available-for-sale investment securities: Beginning balance $ (6 ) $ 2 $ (4 ) $ (7 ) $ 3 $ (4 ) Net unrealized (losses) gains arising during the period (7 ) 3 (4 ) 5 (2 ) 3 Reclassification of net losses (gains) to Other, net 2 (1 ) 1 (4 ) 1 (3 ) Net change (5 ) 2 (3 ) 1 (1 ) — Ending balance $ (11 ) $ 4 $ (7 ) $ (6 ) $ 2 $ (4 ) Unrealized gains (losses) on cash flow hedges: Beginning balance $ 51 $ (12 ) $ 39 $ (15 ) $ 3 $ (12 ) Unrealized gains arising during the period 232 (57 ) 175 83 (19 ) 64 Reclassifications of net (gains) losses to: Cost of revenues (109 ) 26 (83 ) (14 ) 3 (11 ) Selling, general and administrative expenses (20 ) 4 (16 ) (3 ) 1 (2 ) Net change 103 (27 ) 76 66 (15 ) 51 Ending balance $ 154 $ (39 ) $ 115 $ 51 $ (12 ) $ 39 Accumulated other comprehensive income (loss): Beginning balance $ (104 ) $ (10 ) $ (114 ) $ (112 ) $ 6 $ (106 ) Other comprehensive income (loss) 209 (25 ) 184 8 (16 ) (8 ) Ending balance $ 105 $ (35 ) $ 70 $ (104 ) $ (10 ) $ (114 )

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum rental payments under non-cancelable operating leases	Future minimum payments on our operating leases as of December 31, 2018 were as follows: Operating lease obligation (in millions) 2019 $ 226 2020 197 2021 157 2022 121 2023 90 Thereafter 197 Total minimum lease payments $ 988
Schedule of future minimum payments on capital leases	Future minimum payments on our capital leases as of December 31, 2018 were as follows: Capital lease obligation (in millions) 2019 $ 17 2020 13 2021 10 2022 8 2023 4 Thereafter 19 Total minimum lease payments 71 Interest (10 ) Present value of minimum lease payments $ 61

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Share-based Compensation [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: 2018 2017 2016 (in millions) Cost of revenues $ 62 $ 55 $ 53 Selling, general and administrative expenses 205 166 164 Total stock-based compensation expense $ 267 $ 221 $ 217 Income tax benefit $ 66 $ 101 $ 49
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, 2018 , 2017 , and 2016 based upon the following assumptions and were as follows: 2018 2017 2016 Dividend yield 1.0 % 1.0 % 0.0 % Weighted average volatility factor 21.0 % 24.3 % 26.5 % Weighted average expected life (in years) 0.25 0.25 0.25 Weighted average risk-free interest rate 1.9 % 0.9 % 0.4 % Weighted average grant date fair value $ 10.87 $ 9.23 $ 8.74
Summary Of The Activity For Performance Stock Units	The presentation reflects the number of PSUs at the maximum performance milestones. Number of Units (in millions) Weighted Average Grant Date Fair Value (in dollars) Unvested at January 1, 2018 2.7 $ 59.15 Granted 1.8 81.98 Vested (0.7 ) 55.87 Forfeited (0.2 ) 69.86 Reduction due to the achievement of lower than maximum performance milestones (0.3 ) 60.31 Unvested at December 31, 2018 3.3 $ 71.59
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, 2018 and changes during the year then ended is presented below: Number of Units (in millions) Weighted Average Grant Date Fair Value (in dollars) Unvested at January 1, 2018 5.2 $ 63.80 Granted 2.8 74.94 Vested (2.5 ) 64.05 Forfeited (0.5 ) 65.93 Unvested at December 31, 2018 5.0 $ 69.64

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting Information, Revenue for Reportable Segment [Abstract]
Revenues From External Customers And Segment Operating Profit	Revenues from external customers and segment operating profit, before unallocated costs, by reportable segment were as follows: 2018 (1) 2017 2016 (2) (in millions) Revenues: Financial Services $ 5,845 $ 5,636 $ 5,366 Healthcare 4,668 4,263 3,871 Products and Resources 3,415 3,040 2,660 Communications, Media and Technology 2,197 1,871 1,590 Total revenues $ 16,125 $ 14,810 $ 13,487 Segment Operating Profit: Financial Services $ 1,757 $ 1,771 $ 1,707 Healthcare 1,431 1,301 1,153 Products and Resources 1,043 923 851 Communications, Media and Technology 700 601 488 Total segment operating profit 4,931 4,596 4,199 Less: unallocated costs 2,130 2,115 1,910 Income from operations $ 2,801 $ 2,481 $ 2,289
Revenues And Long-Lived Assets By Geographic Area	Revenues and long-lived assets, by geographic area, were as follows: 2018 2017 2016 (in millions) Revenues: (1) North America (2) $ 12,293 $ 11,450 $ 10,546 United Kingdom 1,274 1,150 1,176 Rest of Europe 1,563 1,248 969 Europe - Total 2,837 2,398 2,145 Rest of World (3) 995 962 796 Total $ 16,125 $ 14,810 $ 13,487 2018 2017 2016 (in millions) Long-lived Assets: (4) North America (2) $ 436 $ 360 $ 279 Europe 105 63 52 Rest of World (3)(5) 853 901 980 Total $ 1,394 $ 1,324 $ 1,311 _________________ (1) Revenues are attributed to regions based upon customer location. (2) Substantially all relates to the United States. (3) Includes our operations in Asia Pacific, the Middle East and Latin America. (4) Long-lived assets include property and equipment, net of accumulated depreciation and amortization. (5) Substantially all of these long-lived assets relate to our operations in India.

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Data [Abstract]
Summary Of Quarterly Financial Data	Summarized quarterly results for the two years ended December 31, 2018 are as follows: Three Months Ended 2018 (1) March 31 June 30 September 30 December 31 Full Year (in millions, except per share data) Revenues $ 3,912 $ 4,006 $ 4,078 $ 4,129 $ 16,125 Cost of revenues (exclusive of depreciation and amortization expense shown separately below) 2,401 2,417 2,480 2,540 9,838 Selling, general and administrative expenses 711 805 734 776 3,026 Depreciation and amortization expense 107 114 119 120 460 Income from operations 693 670 745 693 2,801 Net income 520 456 477 648 2,101 Basic earnings per share $ 0.89 $ 0.78 $ 0.82 $ 1.12 $ 3.61 Diluted earnings per share $ 0.88 $ 0.78 $ 0.82 $ 1.12 $ 3.60 Three Months Ended 2017 March 31 June 30 September 30 December 31 Full Year (in millions, except per share data) Revenues $ 3,546 $ 3,670 $ 3,766 $ 3,828 $ 14,810 Cost of revenues (exclusive of depreciation and amortization expense shown separately below) 2,194 2,261 2,337 2,360 9,152 Selling, general and administrative expenses 686 709 674 700 2,769 Depreciation and amortization expense 96 94 107 111 408 Income from operations 570 606 648 657 2,481 Net income (loss) (2) 557 470 495 (18 ) 1,504 Basic earnings (losses) per share (3) $ 0.92 $ 0.80 $ 0.84 $ (0.03 ) $ 2.54 Diluted earnings (losses) per share (3) $ 0.92 $ 0.80 $ 0.84 $ (0.03 ) $ 2.53 _________________ (1) Results for 2018 are presented under the New Revenue Standard, while prior period amounts are not adjusted and continue to be reported in accordance with our historic accounting policies. See Note 3 for additional information. (2) The net loss for the quarter ended December 31, 2017, includes the one-time provisional incremental income tax expense relating to the Tax Reform Act. See Note 11 . (3) The sum of the quarterly basic and diluted earnings (losses) per share for each of the four quarters may not equal the earnings (losses) per share for the year due to rounding.

Business Description and Summ_3

Business Description and Summary of Significant Accounting Policies (Narrative) (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Leasehold for land lease terms, maximum years	99 years
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share - less than	1	1	1

Business Description and Summ_4

Business Description and Summary of Significant Accounting Policies Accounting Standard Updates (Details) - USD ($) $ in Millions	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 121
Accumulated other comprehensive income (loss):
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		(1)
Accumulated other comprehensive income (loss): | Adjustments for New Accounting Principle, Early Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		(1)
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		122
Retained Earnings [Member] | Adjustments for New Accounting Principle, Early Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 1
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 750
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 800

Internal Investigation and Re_2

Internal Investigation and Related Matters (Details) - USD ($) $ in Millions

3 Months Ended

12 Months Ended

Mar. 31, 2019

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Loss Contingencies [Line Items]

Selling, general and administrative expenses

$ 776

$ 734

$ 805

$ 711

$ 700

$ 674

$ 709

$ 686

$ 3,026

$ 2,769

$ 2,731

Out of period adjustment [Member] | Internal Investigation and Related Matters [Member]

Loss Contingencies [Line Items]

Selling, general and administrative expenses

$ 4

Subsequent Event [Member] | FCPA Accrual [Member]

Loss Contingencies [Line Items]

Litigation Settlement, Amount Awarded to Other Party

$ 28

Revenues (Details)

Revenues (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 121
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax Impact	37
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	122
Retained Earnings [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 121

Revenues Schedule of Effect of

Revenues Schedule of Effect of New Accounting Pronouncements on Affected Financial Position Line Items (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Trade accounts receivable, net	$ 3,257	$ 2,865
Unbilled accounts receivable	0	357
Other current assets	909	833
Total current assets	8,677	9,111
Other noncurrent assets	689	448
Total assets	15,913	15,221
Liabilities [Abstract]
Deferred revenue	286	383
Total current liabilities	2,777	2,839
Deferred revenue, noncurrent	62	104
Deferred income tax liabilities, net	183	146
Total liabilities	4,489	4,552
Stockholders' Equity:
Retained earnings	11,485	10,544
Total stockholders’ equity	11,424	10,669	$ 10,728	$ 9,278
Total liabilities and stockholders’ equity	15,913	$ 15,221
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Assets
Trade accounts receivable, net	3,115
Unbilled accounts receivable	485
Other current assets	604
Other noncurrent assets	615
Liabilities [Abstract]
Deferred revenue	498
Deferred revenue, noncurrent	108
Deferred income tax liabilities, net	118
Stockholders' Equity:
Retained earnings	11,256
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Assets
Trade accounts receivable, net	142
Unbilled accounts receivable	(485)
Other current assets	305
Total current assets	(38)
Other noncurrent assets	74
Total assets	36
Liabilities [Abstract]
Deferred revenue	(212)
Total current liabilities	(212)
Deferred revenue, noncurrent	(46)
Deferred income tax liabilities, net	65
Total liabilities	(193)
Stockholders' Equity:
Retained earnings	229
Total stockholders’ equity	229
Total liabilities and stockholders’ equity	$ 36

Revenues Schedule of Effect o_2

Revenues Schedule of Effect of New Accounting Pronouncements on Affected Statement of Operations Line Items (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues	$ 4,129	$ 4,078	$ 4,006	$ 3,912	$ 3,828	$ 3,766	$ 3,670	$ 3,546	$ 16,125	$ 14,810	$ 13,487
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)	2,540	2,480	2,417	2,401	2,360	2,337	2,261	2,194	9,838	9,152	8,108
Selling, general and administrative expenses	776	734	805	711	700	674	709	686	3,026	2,769	2,731
Depreciation and amortization expense	120	119	114	107	111	107	94	96	460	408	359
Income from operations	693	745	670	693	657	648	606	570	2,801	2,481	2,289
Total other income (expense), net									(4)	174	68
Income before provision for income taxes									2,797	2,655	2,357
Provision for income taxes									(698)	(1,153)	(805)
Income from equity method investments									2	2	1
Net income	$ 648	$ 477	$ 456	$ 520	$ (18)	$ 495	$ 470	$ 557	$ 2,101	$ 1,504	$ 1,553
Basic earnings per share	$ 1.12	$ 0.82	$ 0.78	$ 0.89	$ (0.03)	$ 0.84	$ 0.80	$ 0.92	$ 3.61	$ 2.54	$ 2.56
Diluted earnings per share	$ 1.12	$ 0.82	$ 0.78	$ 0.88	$ (0.03)	$ 0.84	$ 0.80	$ 0.92	$ 3.60	$ 2.53	$ 2.55
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues									$ 16,029
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)									9,876
Selling, general and administrative expenses									3,026
Depreciation and amortization expense									460
Income from operations									2,667
Total other income (expense), net									(5)
Income before provision for income taxes									2,662
Provision for income taxes									(671)
Income from equity method investments									2
Net income									$ 1,993
Basic earnings per share									$ 3.42
Diluted earnings per share									$ 3.41
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues									$ 96
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)									(38)
Selling, general and administrative expenses									0
Depreciation and amortization expense									0
Income from operations									134
Total other income (expense), net									1
Income before provision for income taxes									135
Provision for income taxes									(27)
Income from equity method investments									0
Net income									$ 108
Basic earnings per share									$ 0.19
Diluted earnings per share									$ 0.19

Revenues Capitalized Costs to F

Revenues Capitalized Costs to Fulfill Contract with Customer (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Revenues [Abstract]
Balance - January 1, 2018	$ 303
Amortization expense	(70)
Costs Capitalized	170
Other	(3)
Balance - December 31, 2018	$ 400

Revenues Significant Movements

Revenues Significant Movements in Contract Assets (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Revenues [Abstract]
Balance - January 1, 2018	$ 306
Revenues recognized during the period but not billed	285
Amounts reclassified to accounts receivable	(282)
Other	(4)
Balance - December 31, 2018	$ 305

Revenues Significant Movement_2

Revenues Significant Movements in Deferred Revenue Balances (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Revenues [Abstract]
Balance - January 1, 2018	$ 431
Amounts billed but not recognized as revenues	204
Revenues recognized related to the opening balance of deferred revenue	(284)
Other	(3)
Balance - December 31, 2018	$ 348

Revenues Remaining Performance

Revenues Remaining Performance Obligations Narrative (Details) $ in Millions	Dec. 31, 2018USD ($)
Revenues [Abstract]
Revenue, Remaining Performance Obligation	$ 1,852
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
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	68.00%

Revenues Disaggregation of Reve

Revenues Disaggregation of Revenue (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Disaggregation of Revenue [Line Items]
Revenues	$ 16,125
Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	8,470
Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	5,966
Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,689
North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	12,293
United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,274
Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,563
Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,837
Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	995
Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	9,309
Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	6,816
Financial Services
Disaggregation of Revenue [Line Items]
Revenues	5,845
Financial Services | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,762
Financial Services | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,859
Financial Services | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	224
Financial Services | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,162
Financial Services | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	481
Financial Services | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	666
Financial Services | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,147
Financial Services | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	536
Financial Services | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,571
Financial Services | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,274
Healthcare
Disaggregation of Revenue [Line Items]
Revenues	4,668
Healthcare | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,836
Healthcare | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,852
Healthcare | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	980
Healthcare | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,254
Healthcare | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	91
Healthcare | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	270
Healthcare | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	361
Healthcare | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	53
Healthcare | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,553
Healthcare | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,115
Products and Resources
Disaggregation of Revenue [Line Items]
Revenues	3,415
Products and Resources | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,506
Products and Resources | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,521
Products and Resources | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	388
Products and Resources | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,397
Products and Resources | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	358
Products and Resources | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	440
Products and Resources | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	798
Products and Resources | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	220
Products and Resources | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,024
Products and Resources | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,391
Communication, Media and Technology [Member]
Disaggregation of Revenue [Line Items]
Revenues	2,197
Communication, Media and Technology [Member] | Time-and-materials Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,366
Communication, Media and Technology [Member] | Fixed-price Contract [Member]
Disaggregation of Revenue [Line Items]
Revenues	734
Communication, Media and Technology [Member] | Transaction Or Volume-Based [Member]
Disaggregation of Revenue [Line Items]
Revenues	97
Communication, Media and Technology [Member] | North America [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,480
Communication, Media and Technology [Member] | United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	344
Communication, Media and Technology [Member] | Europe, excluding United Kingdom [Member]
Disaggregation of Revenue [Line Items]
Revenues	187
Communication, Media and Technology [Member] | Europe [Member]
Disaggregation of Revenue [Line Items]
Revenues	531
Communication, Media and Technology [Member] | Rest of World [Member]
Disaggregation of Revenue [Line Items]
Revenues	186
Communication, Media and Technology [Member] | Consulting And Technology Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,161
Communication, Media and Technology [Member] | Outsourcing Services [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 1,036

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) - Other acquisitions [Member] $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)business	Dec. 31, 2017USD ($)business	Dec. 31, 2016USD ($)business
Business Acquisition [Line Items]
Number of business combinations | business	5	5	8
Total consideration		$ 233	$ 287
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	$ 1,122	$ 233	$ 287

Business Combinations Allocatio

Business Combinations Allocation of Purchase Price (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 3,481	$ 2,704	$ 2,554
Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years 3 months 18 days
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years 8 months 12 days
Other acquisitions [Member]
Business Acquisition [Line Items]
Cash	$ 15	8	17
Current assets	101	47	84
Property, plant and equipment and other noncurrent assets	15	19	53
Goodwill	796	125	157
Current liabilities	(67)	(50)	(173)
Noncurrent liabilities	(50)	(67)	(51)
Purchase price	1,122	233	287
Other acquisitions [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	276	$ 147	$ 199
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		10 years 7 months 6 days	6 years 7 months 6 days
Other acquisitions [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	27	$ 4	$ 1
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		2 years 4 months 24 days	3 years 3 months 18 days
Softvision [Member]
Business Acquisition [Line Items]
Cash	4
Current assets	54
Property, plant and equipment and other noncurrent assets	7
Goodwill	385
Current liabilities	(47)
Noncurrent liabilities	(4)
Purchase price	541
Softvision [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	133
Softvision [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	9
Bolder [Member]
Business Acquisition [Line Items]
Cash	7
Current assets	32
Property, plant and equipment and other noncurrent assets	7
Goodwill	335
Current liabilities	(11)
Noncurrent liabilities	(37)
Purchase price	472
Bolder [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	113
Bolder [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	17
Others [Member]
Business Acquisition [Line Items]
Cash	4
Current assets	15
Property, plant and equipment and other noncurrent assets	1
Goodwill	76
Current liabilities	(9)
Noncurrent liabilities	(9)
Purchase price	109
Others [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets acquired	30
Others [Member] | Other Intangible Assets [Member]
Business Acquisition [Line Items]
Intangible assets acquired	1
Trademarks [Member] | Other acquisitions [Member]
Business Acquisition [Line Items]
Intangible assets acquired	9
Trademarks [Member] | Softvision [Member]
Business Acquisition [Line Items]
Intangible assets acquired	0
Trademarks [Member] | Bolder [Member]
Business Acquisition [Line Items]
Intangible assets acquired	9
Trademarks [Member] | Others [Member]
Business Acquisition [Line Items]
Intangible assets acquired	$ 0

Realignment Charges (Details)

Realignment Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 19	$ 72	$ 0
Special Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	18	53
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0	18
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 1	$ 1

Investments Short-term investme

Investments Short-term investments (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Short-term Investments [Abstract]
Equity investment securities	$ 25	$ 25
Available-for-sale Securities, Current	1,760	1,972
Debt Securities, Held-to-maturity, Current	1,065	745
Debt Securities, Time Deposits	500	389
Short-term Investments	3,350	$ 3,131
Restricted Investments	$ 423

Investments Long-term investmen

Investments Long-term investments (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Long-term Investments [Abstract]
Equity and Cost Method Investments	$ 74	$ 74
Debt Securities, Held-to-maturity, Noncurrent	6	161
Long-term Investments	$ 80	$ 235

Investments Trading Securities

Investments Trading Securities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt and Equity Securities, FV-NI [Line Items]
Equity investment securities	$ 25	$ 25
Equity Investment Securities, Realized Gain (Loss)	$ 0	$ 0

Investments Available-for-sale

Investments Available-for-sale securities - amortized cost, gross unrealized gains and losses and fair value (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,772	$ 1,983
Gains	1	0
Losses	13	11
Fair Value	1,760	1,972
U.S. Treasury And Agency Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	630	667
Gains	1	0
Losses	6	6
Fair Value	625	661
Corporate And Other Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	420	439
Gains	0	0
Losses	4	2
Fair Value	416	437
Certificates of deposit and commercial paper [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	296	450
Gains	0	0
Losses	0	0
Fair Value	296	450
Asset-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	336	297
Gains	0	0
Losses	2	2
Fair Value	334	295
Municipal Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	90	130
Gains	0	0
Losses	1	1
Fair Value	$ 89	$ 129

Investments Available-for-sal_2

Investments Available-for-sale securities in a continuous unrealized loss position (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	$ 597	$ 1,165
Unrealized losses, less than 12 months	1	7
Fair value, 12 months or more	943	362
Unrealized losses, 12 months or more	12	4
Total fair value	1,540	1,527
Total unrealized loss	13	11
U.S. Treasury And Agency Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	84	519
Unrealized losses, less than 12 months	0	4
Fair value, 12 months or more	446	124
Unrealized losses, 12 months or more	6	2
Total fair value	530	643
Total unrealized loss	6	6
Corporate And Other Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	108	297
Unrealized losses, less than 12 months	1	1
Fair value, 12 months or more	254	126
Unrealized losses, 12 months or more	3	1
Total fair value	362	423
Total unrealized loss	4	2
Certificates of deposit and commercial paper [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	295	49
Unrealized losses, less than 12 months	0	0
Fair value, 12 months or more	0	0
Unrealized losses, 12 months or more	0	0
Total fair value	295	49
Total unrealized loss	0	0
Asset-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	93	193
Unrealized losses, less than 12 months	0	1
Fair value, 12 months or more	179	94
Unrealized losses, 12 months or more	2	1
Total fair value	272	287
Total unrealized loss	2	2
Municipal Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	17	107
Unrealized losses, less than 12 months	0	1
Fair value, 12 months or more	64	18
Unrealized losses, 12 months or more	1	0
Total fair value	81	125
Total unrealized loss	$ 1	$ 1

Investments Available-for-sal_3

Investments Available-for-sale securities - contractual maturities (Details) $ in Millions	Dec. 31, 2018USD ($)
Debt Securities, Available-for-sale, Maturity, Amortized Cost, Rolling Maturity [Abstract]
Due within one year	$ 569
Due after one year up to two years	544
Due after two years up to three years	267
Due after three years	56
Asset-backed securities	336
Amortized Cost	1,772
Debt Securities, Available-for-sale, Maturity, Fair Value, Rolling Maturity [Abstract]
Due within one year	567
Due after one year up to two years	537
Due after two years up to three years	265
Due after three years	57
Asset-backed securities	334
Fair value	$ 1,760

Investments Available-for-sal_4

Investments Available-for-sale securities - proceeds from sales, gross gains and losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Securities, Available-for-sale [Line Items]
Proceeds from Sale of Available-for-sale Securities	$ 1,285	$ 2,922	$ 3,541
Gross Gains	0	1	5
Gross Losses	4	3	4
Net realized (losses) gains on sales of available-for-sale investment securities	$ (4)	$ (2)	$ 1

Investments Held-to-maturity se

Investments Held-to-maturity securities - amortized cost, gross unrealized gains and losses and fair value (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost, Current	$ 1,065	$ 745
Unrealized gains	0	0
Unrealized Losses	(1)	(4)
Fair Value	1,070	902
Amortized Cost, Noncurrent	6	161
Debt Securities, Held-to-maturity	1,071	906
Short-term Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost, Current	1,065	745
Unrealized gains	0	0
Unrealized Losses	(1)	(3)
Fair Value	1,064	742
Corporate And Other Debt Securities [Member] | Long-term investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Unrealized gains	0	0
Unrealized Losses	0	(1)
Fair Value	6	160
Amortized Cost, Noncurrent	6	161
Corporate And Other Debt Securities [Member] | Short-term Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost, Current	546	346
Unrealized gains	0	0
Unrealized Losses	0	(1)
Fair Value	546	345
Commercial Paper [Member] | Short-term Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost, Current	519	399
Unrealized gains	0	0
Unrealized Losses	(1)	(2)
Fair Value	$ 518	$ 397

Investments Held-to-maturity _2

Investments Held-to-maturity securities in a continuous unrealized loss position (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Fair value, less than 12 months	$ 531	$ 867
Unrealized losses, less than 12 months	(1)	(4)
Fair value, 12 months or more	57	0
Unrealized losses, 12 months or more	0	0
Total fair value	588	867
Total unrealized losses	(1)	(4)
Corporate And Other Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair value, less than 12 months	263	473
Unrealized losses, less than 12 months	0	(2)
Fair value, 12 months or more	57	0
Unrealized losses, 12 months or more	0	0
Total fair value	320	473
Total unrealized losses	0	(2)
Commercial Paper [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair value, less than 12 months	268	394
Unrealized losses, less than 12 months	(1)	(2)
Fair value, 12 months or more	0	0
Unrealized losses, 12 months or more	0	0
Total fair value	268	394
Total unrealized losses	$ (1)	$ (2)

Investments Held-to-maturity _3

Investments Held-to-maturity securities - contractual maturities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost, due within one year	$ 1,065
Fair value, due within one year	1,064
Amortized cost, due after one year up to two years	6
Fair value, due after one year up to two years	6
Debt Securities, Held-to-maturity	1,071	$ 906
Debt Securities, Held-to-maturity, Fair Value	$ 1,070	$ 902

Investments Equity Method Inves

Investments Equity Method Investments (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Apr. 30, 2016
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Equity Method Investments	$ 66	$ 67
Equity Method Investment, Ownership Percentage			49.00%

Investments Cost Method Investm

Investments Cost Method Investments (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Investments, All Other Investments [Abstract]
Cost Method Investments	$ 8	$ 7

Property and Equipment, net (Na

Property and Equipment, net (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Capital Leased Assets, Gross	$ 73	$ 44
Capitalized Computer Software, Gross	85	52
Capitalized Computer Software, Accumulated Amortization	24	12
Capitalized Computer Software, Amortization	14
Property, Plant and Equipment [Member]
Depreciation	$ 347	$ 313	$ 266

Property and Equipment, net (Sc

Property and Equipment, net (Schedule Of Property And Equipment, Net) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 3,184	$ 2,840
Accumulated depreciation and amortization	(1,790)	(1,516)
Property and Equipment, net	$ 1,394	1,324	$ 1,311
Buildings [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	30 years
Property and Equipment, gross	$ 839	836
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 412	364
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	$ 721	594
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	$ 639	511
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	$ 19	19
Leasehold Land [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	60	63
Capital Work-in-Progress [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	156	145
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, gross	$ 338	$ 308

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, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 2,704	$ 2,554
Additions	795	123
Foreign currency translation adjustments	(18)	27
Goodwill, Ending Balance	3,481	2,704
Financial Services
Goodwill [Roll Forward]
Goodwill, Beginning Balance	265	227
Additions	152	27
Foreign currency translation adjustments	(6)	11
Goodwill, Ending Balance	411	265
Healthcare
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,106	2,089
Additions	365	13
Foreign currency translation adjustments	(2)	4
Goodwill, Ending Balance	2,469	2,106
Products and Resources
Goodwill [Roll Forward]
Goodwill, Beginning Balance	240	159
Additions	152	72
Foreign currency translation adjustments	(8)	9
Goodwill, Ending Balance	384	240
Communications, Media and Technology
Goodwill [Roll Forward]
Goodwill, Beginning Balance	93	79
Additions	126	11
Foreign currency translation adjustments	(2)	3
Goodwill, Ending Balance	$ 217	$ 93

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ (618)	$ (471)
Intangible Assets, Gross (Excluding Goodwill)	1,768	1,452
Intangible assets, net	1,150	981
Indefinite life trademarks	72	63
Amortization of intangibles	151	130	$ 113
Amortization Expense Recorded As A Reduction Of Revenues	38	35	$ 20
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,277	1,005
Accumulated amortization	(398)	(304)
Net carrying amount	879	701
Developed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	355	333
Accumulated amortization	(187)	(140)
Net carrying amount	168	193
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	64	51
Accumulated amortization	(33)	(27)
Net carrying amount	$ 31	$ 24

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets, net (Schedule Of Estimated Amortization Expense) (Details) $ in Millions	Dec. 31, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,018	$ 167
2,019	158
2,020	153
2,021	137
2,022	$ 83

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Accrued Expenses And Other Current Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Compensation and benefits	$ 1,216	$ 1,272
Customer volume and other incentives	323	289
Derivative financial instruments	25	5
Loss Contingency, Accrual, Current		0
Income taxes	162	48
Professional fees	110	100
Travel and entertainment	34	32
Other	369	325
Accrued expenses and other current liabilities	2,267	$ 2,071
FCPA Accrual [Member]
Loss Contingencies [Line Items]
Loss Contingency, Accrual, Current	$ 28

Debt (Details)

Debt (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018	Nov. 30, 2018USD ($)	Dec. 31, 2014USD ($)
Maximum [Member]
Debt Instrument [Line Items]
Financial covenant, leverage ratio	3.50
Debt Instrument, Covenant Compliance, Leverage Ratio Following Material Acquisition(s)	3.75
Term Loan and Revolving Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
Term Loan and Revolving Credit Facility [Member] | Eurocurrency [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.875%
Term Loan and Revolving Credit Facility [Member] | Minimum [Member] | Eurocurrency [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
Term Loan and Revolving Credit Facility [Member] | Minimum [Member] | Eurocurrency Without Debt Ratings [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.875%
Term Loan and Revolving Credit Facility [Member] | Maximum [Member] | Eurocurrency [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
Term Loan and Revolving Credit Facility [Member] | Maximum [Member] | Eurocurrency Without Debt Ratings [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
Term Loan [Member]
Debt Instrument [Line Items]
Principal amount of debt		$ 750	$ 1,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity		$ 1,750	$ 750

Debt (Short-Term Debt (Details)

Debt (Short-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Total short-term debt	$ 9	$ 175
Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Notes drawn under Revolving Facility	$ 0	$ 75
Weighted average interest rate		4.50%
Term Loan [Member]
Short-term Debt [Line Items]
Weighted average interest rate	3.30%	2.40%
Term Loan - Current Maturities	$ 9	$ 100

Debt (Long-Term Debt) (Details)

Debt (Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt	$ 750
Long-term debt, net of current maturities	736	$ 698
Term Loan [Member]
Debt Instrument [Line Items]
Long-term debt	750	800
Less: Current portion	(9)	(100)
Long-term debt, net of current maturities	736	698
Term Loan and Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ (5)	$ (2)

Debt (Debt Maturities) (Details

Debt (Debt Maturities) (Details) $ in Millions	Dec. 31, 2018USD ($)
Debt Disclosure [Abstract]
2,019	$ 9
2,020	38
2,021	38
2,022	38
2,023	627
Long-term debt	$ 750

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit)		$ 617
Income Tax Expense (Benefit)	$ 698	1,153	$ 805
Deferred income taxes related to MAT	$ 228	$ 278
Minimum alternative tax, expiration period (in years)	15 years	10 years
Incentive period for SEZs, years	15 years
Regular corporate income tax rate in India	34.90%
Minimum alternative tax, rate	21.60%
Income tax holiday, increase in net income	$ 146	$ 217	$ 203
Increase in diluted EPS	$ 0.25	$ 0.36	$ 0.33
Accrued interest and penalties	$ 11	$ 8
Tax Cuts and Jobs Act of 2017, Measurement Period Adjustment, Income Tax Expense (Benefit)	(5)
Tax Cuts and Jobs Act of 2017, Provisional Income Tax Expense (Benefit)	612
Restricted Investments	423
India
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrepatriated foreign earnings	4,679
Foreign Tax Authority [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Net operating loss carryforward	39
Internal Revenue Service (IRS) [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Net operating loss carryforward	10
Pro Forma [Member] | India
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Repatriation of foreign earnings	$ 980

Income Taxes (Schedule Of Incom

Income Taxes (Schedule Of Income Before Provision For Income Tax) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
United States	$ 947	$ 810	$ 752
Foreign	1,850	1,845	1,605
Income before provision for income taxes	$ 2,797	$ 2,655	$ 2,357

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components Of Provision For Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal and state	$ 241	$ 767	$ 544
Foreign	449	262	352
Total current provision	690	1,029	896
Deferred:
Federal and state	1	102	(44)
Foreign	7	22	(47)
Total deferred (benefit) provision	8	124	(91)
Total provision for income taxes	$ 698	$ 1,153	$ 805

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Tax expense, at U.S. federal statutory rate, amount	$ 587	$ 929	$ 825
State and local income taxes, net of federal benefit, amount	56	39	42
Non-taxable income for Indian tax purposes, amount	(146)	(216)	(203)
Rate differential on foreign earnings, amount	206	(76)	(55)
Net impact related to the implementation of the Tax Reform Act	(5)	617	0
Credits and other incentives, amount	(19)	(37)	(57)
Other adjustments, amount	31	(30)	31
Total provision for income taxes	$ 698	$ 1,153	$ 805
Tax expense, at U.S. federal statutory rate, percentage	21.00%	35.00%	35.00%
State and local income taxes, net of federal benefit, percentage	2.00%	1.50%	1.80%
Non-taxable income for Indian tax purposes, percentage	(5.20%)	(8.20%)	(8.60%)
Rate differential on foreign earnings, percentage	7.40%	(2.90%)	(2.30%)
Net impact related to the Tax Reform Act, percentage	(0.20%)	23.20%	0.00%
Credits and other incentives, percent	(0.70%)	(1.40%)	(2.40%)
Other adjustments, percent	1.10%	(1.10%)	1.30%
Total provision for income taxes, percentage	25.00%	43.40%	34.20%
2016 India Cash Remittance [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Other adjustments, amount	$ 0	$ 0	$ 238
Other adjustments, percent	0.00%	0.00%	10.10%
Recognition of previously unrecognized income tax benefits related to uncertain tax positions [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Other adjustments, amount	$ (12)	$ (73)	$ (16)
Other adjustments, percent	(0.40%)	(2.70%)	(0.70%)

Income Taxes (Schedule Of Defer

Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred income tax assets:
Net operating losses	$ 13	$ 15
Revenue recognition	51	55
Compensation and benefits	133	125
Stock-based compensation	17	14
Minimum alternative tax (MAT) and other credits	340	369
Other accrued expenses	60	22
Deferred income tax assets, gross	614	600
Less valuation allowance	(11)	(10)
Deferred income tax assets, net	603	590
Deferred income tax liabilities:
Depreciation and amortization	256	209
Deferred Tax Liabilities, Deferred Expense	79	65
Other	9	44
Deferred income tax liabilities	344	318
Net deferred income tax assets	$ 259	$ 272

Income Taxes (Summary Of Change

Income Taxes (Summary Of Changes In Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in unrecognized income tax benefits
Balance, beginning of year	$ 97	$ 151	$ 139
Additions based on tax positions related to the current year	8	17	11
Additions for tax positions of prior years	19	2	19
Unrecognized Tax Benefits, Increase Resulting from Acquisition	6	0	0
Reductions for tax positions due to lapse of statutes of limitations	(12)	(41)	(15)
Reductions for tax positions of prior years	0	(32)	(1)
Settlements	0	0	0
Foreign currency exchange movement	(1)	0	(2)
Balance, end of year	$ 117	$ 97	$ 151

Income Taxes Income Taxes (Narr

Income Taxes Income Taxes (Narrative) (One-time Transaction) (Details) $ in Millions	1 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2018INR (₨)	Apr. 30, 2018INR (₨)
One-time Transaction [Table] [Line Items]
Income Tax Expense (Benefit)		$ 698	$ 1,153	$ 805
Restricted Investments		423
Foreign Tax Authority [Member] | Indian Income Tax Department (ITD) [Member]
One-time Transaction [Table] [Line Items]
Deposits Assets		$ 71				₨ 0
Deposits Assets, Percent Disputed Tax Amount		15.00%				15.00%
Restricted Investments			$ 0
Restricted Investments Initially Deposited		$ 404					₨ 28
Foreign Tax Authority [Member] | 2016 India Cash Remittance [Member] | Indian Income Tax Department (ITD) [Member]
One-time Transaction [Table] [Line Items]
Foreign Earnings Repatriated	$ 2,800
Income Tax Expense (Benefit)				$ 135
Income Tax, Disputed Amount		$ 475				₨ 0
Foreign Tax Authority [Member] | 2013 India Share Repurchase [Member] | Indian Income Tax Department (ITD) [Member]
One-time Transaction [Table] [Line Items]
Foreign Earnings Repatriated					$ 523

Derivative Financial Instrume_3

Derivative Financial Instruments (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash flow hedge losses expected to be reclassified to earnings within the next 12 months	$ (9)
Cash flow hedge ineffectiveness is immaterial	Hedge ineffectiveness was immaterial for all periods presented.

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, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative assets fair value	$ 27	$ 154
Derivative liabilities fair value	34	5
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	26	154
Derivative liabilities fair value	30	0
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	11	134
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member] | Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	15	20
Cash Flow Hedges [Member] | 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	21	0
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative liabilities fair value	9	0
Other Derivatives [Member] | Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative assets fair value	1	0
Derivative liabilities fair value	4	5
Other Derivatives [Member] | 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	0
Other Derivatives [Member] | 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	$ 4	$ 5

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, 2018	Dec. 31, 2017
Foreign Exchange Forward Contracts [Member]
Derivative [Line Items]
Derivative, notional amount	$ 2,168	$ 1,905
Net unrealized (losses) included in accumulated other comprehensive income (loss), net of taxes	(3)	115
Foreign Exchange Forward, Maturity 2018 [Member]
Derivative [Line Items]
Derivative, notional amount	0	1,185
Foreign Exchange Forward, Maturity 2019 [Member]
Derivative [Line Items]
Derivative, notional amount	1,388	720
Foreign Exchange Forward, Maturity 2020 [Member]
Derivative [Line Items]
Derivative, notional amount	$ 780	$ 0

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, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 71	$ 129
Cost of revenues
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	61	109
Selling, general and administrative expenses
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	10	20
Foreign Exchange Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
(Increase) Decrease in Derivative Losses Recognized in Accumulated Other Comprehensive Income (Loss) (effective portion)	$ (87)	$ 232

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, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative, notional amount	$ 507	$ 255
Market value	$ (3)	$ (5)

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, 2018	Dec. 31, 2017
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	$ 31	$ (23)

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, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Investments	$ 423
Equity investment securities	25	$ 25
Equity and Cost Method Investments	74	74
Debt Securities, Held-to-maturity, Fair Value	1,070	902
Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investment securities	25	25
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	203	800
Time Deposits, Fair Value Disclosure	500	389
Available-for-sale Securities	1,760	1,972
Fair Value Assets And Liabilities Measured On Recurring Basis	3,526	4,212
Fair Value, Measurements, 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	12	134
Fair Value, Measurements, Recurring [Member] | Accrued Expenses And Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	(25)	(5)
Fair Value, Measurements, 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	15	20
Fair Value, Measurements, Recurring [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	(9)
Fair Value, Measurements, Recurring [Member] | Municipal Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	89	129
Fair Value, Measurements, Recurring [Member] | U.S. Treasury And Agency Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	625	661
Fair Value, Measurements, Recurring [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	416	437
Fair Value, Measurements, Recurring [Member] | Certificates of deposit and commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	296	450
Fair Value, Measurements, Recurring [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	334	295
Fair Value, Measurements, 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	103	334
Fair Value, Measurements, Recurring [Member] | Bank Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	32	80
Fair Value, Measurements, 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	68	386
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	103	334
Time Deposits, Fair Value Disclosure	0	0
Available-for-sale Securities	570	585
Fair Value Assets And Liabilities Measured On Recurring Basis	673	919
Fair Value, Measurements, 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, Measurements, 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]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Measurements, 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, Measurements, 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]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury And Agency Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	570	585
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Certificates of deposit and commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [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	103	334
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	100	466
Time Deposits, Fair Value Disclosure	500	389
Available-for-sale Securities	1,190	1,387
Fair Value Assets And Liabilities Measured On Recurring Basis	2,853	3,293
Fair Value, Measurements, 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	12	134
Fair Value, Measurements, 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]
Foreign Currency Contracts, Liability, Fair Value Disclosure	(25)	(5)
Fair Value, Measurements, 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	15	20
Fair Value, Measurements, 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]
Foreign Currency Contracts, Liability, Fair Value Disclosure	(9)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	89	129
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury And Agency Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	55	76
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	416	437
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Certificates of deposit and commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	296	450
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	334	295
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Certificates of deposit and commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	68
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [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	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Bank Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	32	80
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		386
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Time Deposits, Fair Value Disclosure	0	0
Available-for-sale Securities	0	0
Fair Value Assets And Liabilities Measured On Recurring Basis	0	0
Fair Value, Measurements, 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, Measurements, 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]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0	0
Fair Value, Measurements, 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, Measurements, 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]
Foreign Currency Contracts, Liability, Fair Value Disclosure	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Treasury And Agency Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Certificates of deposit and commercial paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [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	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Long-term investments [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	6	160
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	6	160
Investments, Fair Value Disclosure	6	160
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	6	160
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Investments, Fair Value Disclosure	0	0
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	6	160
Investments, Fair Value Disclosure	6	160
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	6	160
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Investments, Fair Value Disclosure	0	0
Long-term investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	1,064	742
Short-term Investments [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	518	397
Short-term Investments [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	546	345
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	1,064	742
Investments, Fair Value Disclosure	3,324	3,103
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	518	397
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	546	345
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Investments, Fair Value Disclosure	570	585
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	1,064	742
Investments, Fair Value Disclosure	2,754	2,518
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	518	397
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	546	345
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Investments, Fair Value Disclosure	0	0
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	0
Short-term Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate And Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	$ 0	$ 0

Stockholder's Equity Share Repu

Stockholder's Equity Share Repurchase Program (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended			36 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount	$ 5,500			$ 5,500
Stock Repurchase Program, Remaining Authorized Repurchase Amount	2,500			2,500
Repurchases of common stock	$ 1,261	$ 1,889	$ 512
Accelerated Share Repurchases, Number of Shares Delivered	12	28	0
Accelerated Share Repurchases, Settlement (Payment) or Receipt	$ 900	$ 1,800	$ 0	$ 900
Share Repurchases, Other [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchases of common stock, shares		1	1	1
Repurchases of common stock	$ 86	$ 89	$ 72
Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchases of common stock, shares	17	29	9
Common Class A [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchases of common stock, shares	4	0	8
Repurchases of common stock	$ 275	$ 0	$ 440

Stockholder's Equity Accelerate

Stockholder's Equity Accelerated Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accelerated Share Repurchases [Line Items]
Repurchases of common stock	$ 1,261	$ 1,889	$ 512
Accelerated Share Repurchases, Settlement (Payment) or Receipt	$ 900	$ 1,800	$ 0
Accelerated Share Repurchases, Number of Shares Delivered	12	28	0

Stockholder's Equity Accumulate

Stockholder's Equity Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI, beginning balance	$ 10,669	$ 10,728	$ 9,278
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Cumulative effect of change in accounting principle, Net of Tax	121
Other comprehensive income (loss)	(183)	184	(8)
AOCI, ending balance	11,424	10,669	10,728
Foreign currency translation adjustments:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	(38)	(149)	(90)
AOCI Tax, beginning balance	0	0	0
AOCI, beginning balance	(38)	(149)	(90)
Other Comprehensive Income (Loss), before Tax [Abstract]
Other Comprehensive Income (Loss), before Tax	(70)	111	(59)
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Tax	5	0	0
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other comprehensive income (loss)	(65)	111	(59)
AOCI before Tax, ending balance	(108)	(38)	(149)
AOCI Tax, ending balance	5	0	0
AOCI, ending balance	(103)	(38)	(149)
Unrealized (losses) on available-for-sale investment securities:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	(11)	(6)	(7)
AOCI Tax, beginning balance	4	2	3
AOCI, beginning balance	(7)	(4)	(4)
Other Comprehensive Income (Loss), before Tax [Abstract]
OCI, before Reclassifications, before Tax	(5)	(7)	5
Reclassification from AOCI, Current Period, before Tax	4	2	(4)
Other Comprehensive Income (Loss), before Tax	(1)	(5)	1
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss) before Reclassifications, Tax	2	3	(2)
Reclassification from AOCI, Current Period, Tax	(1)	(1)	1
Other Comprehensive Income (Loss), Tax	0	2	(1)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
OCI, before Reclassifications, Net of Tax	(3)	(4)	3
Reclassification from AOCI, Current Period, Net of Tax	3	1	(3)
Other comprehensive income (loss)	(1)	(3)	0
AOCI before Tax, ending balance	(12)	(11)	(6)
AOCI Tax, ending balance	4	4	2
AOCI, ending balance	(8)	(7)	(4)
Unrealized gains (losses) on cash flow hedges:
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	154	51	(15)
AOCI Tax, beginning balance	(39)	(12)	3
AOCI, beginning balance	115	39	(12)
Other Comprehensive Income (Loss), before Tax [Abstract]
OCI, before Reclassifications, before Tax	(87)	232	83
Other Comprehensive Income (Loss), before Tax	(158)	103	66
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss) before Reclassifications, Tax	23	(57)	(19)
Other Comprehensive Income (Loss), Tax	40	(27)	(15)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
OCI, before Reclassifications, Net of Tax	(64)	175	64
Other comprehensive income (loss)	(118)	76	51
AOCI before Tax, ending balance	(4)	154	51
AOCI Tax, ending balance	1	(39)	(12)
AOCI, ending balance	(3)	115	39
Accumulated other comprehensive income (loss):
AOCI Attributable to Parent, Net of Tax [Roll Forward]
AOCI before Tax, beginning balance	105	(104)	(112)
AOCI Tax, beginning balance	(35)	(10)	6
AOCI, beginning balance	70	(114)	(106)
Other Comprehensive Income (Loss), before Tax [Abstract]
Other Comprehensive Income (Loss), before Tax	(229)	209	8
Other Comprehensive Income (Loss), Tax [Abstract]
Cumulative effect of change in accounting principle , Tax	(1)
Other Comprehensive Income (Loss), Tax	45	(25)	(16)
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Cumulative effect of change in accounting principle, Net of Tax	(1)
Other comprehensive income (loss)	(184)	184	(8)
AOCI before Tax, ending balance	(124)	105	(104)
AOCI Tax, ending balance	10	(35)	(10)
AOCI, ending balance	(114)	70	(114)
Cost of revenues | Unrealized gains (losses) on cash flow hedges:
Other Comprehensive Income (Loss), before Tax [Abstract]
Reclassification from AOCI, Current Period, before Tax	(61)	(109)	(14)
Other Comprehensive Income (Loss), Tax [Abstract]
Reclassification from AOCI, Current Period, Tax	15	26	3
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Reclassification from AOCI, Current Period, Net of Tax	(46)	(83)	(11)
Selling, general and administrative expenses | Unrealized gains (losses) on cash flow hedges:
Other Comprehensive Income (Loss), before Tax [Abstract]
Reclassification from AOCI, Current Period, before Tax	(10)	(20)	(3)
Other Comprehensive Income (Loss), Tax [Abstract]
Reclassification from AOCI, Current Period, Tax	2	4	1
Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Reclassification from AOCI, Current Period, Net of Tax	$ (8)	$ (16)	$ (2)

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Insurance Receivable		$ 4								$ 4
Rent expense										282	$ 265	$ 227
Loss Contingencies [Line Items]
Selling, general and administrative expenses		776	$ 734	$ 805	$ 711	$ 700	$ 674	$ 709	$ 686	3,026	2,769	2,731
Loss Contingency, Accrual, Current						$ 0					$ 0
FCPA Accrual [Member]
Loss Contingencies [Line Items]
Loss Contingency, Accrual, Current		$ 28								$ 28
Out of period adjustment [Member] | Internal Investigation and Related Matters [Member]
Loss Contingencies [Line Items]
Selling, general and administrative expenses												$ 4
Subsequent Event [Member] | FCPA Accrual [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded to Other Party	$ 28

Commitments and Contingencies_3

Commitments and Contingencies (Operating Leases) (Details) $ in Millions	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 226
2,020	197
2,021	157
2,022	121
2,023	90
Thereafter	197
Total minimum lease payments	$ 988

Commitments and Contingencies_4

Commitments and Contingencies (Capital Leases) (Details) $ in Millions	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 17
2,020	13
2,021	10
2,022	8
2,023	4
Thereafter	19
Total minimum lease payments	71
Interest	(10)
Present value of minimum lease payments	$ 61

Employee Benefits (Narrative) (

Employee Benefits (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
United States and Europe [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	$ 108	$ 91	$ 76
India
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan expense	$ 88	86	79
Employee contribution percentage, maximum	12.00%
Gratuity Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount accrued under gratuity plan net of fund assets	$ 141	114
Fund assets	136	138
Pension and Other Postretirement Benefits Cost (Reversal of Cost)	$ 53	$ 40	$ 41

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount	$ 20,000,000	$ 40,000,000
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Per Share Amount	$ 0.03	$ 0.07
Unrecognized stock-based compensation expense	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	0.2
2017 Incentive Plan [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares authorized	48.8
Shares available for grant	38.7
Stock Options [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total intrinsic value of options exercised	$ 29,000,000	$ 78,000,000	$ 74,000,000
Restricted Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized stock-based compensation expense	$ 288,000,000
Weighted average remaining requisite service period	2 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 194,000,000	$ 169,000,000	$ 138,000,000
Weighted Average Grant Date Fair Value, Granted	$ 74.94	$ 67.56	$ 55.55
Performance Stock Units [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Unrecognized stock-based compensation expense	$ 67,000,000
Weighted average remaining requisite service period	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 53,000,000	$ 60,000,000	$ 57,000,000
Weighted Average Grant Date Fair Value, Granted	$ 81.98	$ 60.77	$ 55.08
Employee Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares authorized	40
Shares available for grant	11.8
Vesting period	3 months
Eligible employees purchase percentage of whole share of fair market value	90.00%
Shares issued	2.7
Fair value of shares issued	$ 29,000,000
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	3 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, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 267	$ 221	$ 217
Income tax benefit	66	101	49
Cost of revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	62	55	53
Selling, general and administrative expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 205	$ 166	$ 164

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans (Schedule Of Assumptions Used To Calculate The Fair Value Of Option Grants) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Dividend yield	1.00%	1.00%	0.00%
Employee Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average volatility factor	21.00%	24.30%	26.50%
Weighted average expected life (in years)	2 months 30 days	3 months	3 months
Weighted average risk-free interest rate	1.90%	0.90%	0.40%
Weighted average grant date fair value	$ 10.87	$ 9.23	$ 8.74

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans (Summary Of The Activity For Performance Stock Units) (Details) - Performance Stock Units [Member] - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Units
Number of Units, Unvested at beginning of period	2.7
Number of Units, Granted	1.8
Number of Units, Vested	(0.7)
Number of Units, Forfeited	(0.2)
Number of Units, Reduction due to the achievement of lower than maximum performance milestones	0.3
Number of Units, Unvested at end of period	3.3	2.7
Weighted Average Grant Date Fair Value (in dollars)
Weighted Average Grant Date Fair Value, Unvested at beginning of period	$ 59.15
Weighted Average Grant Date Fair Value, Granted	81.98	$ 60.77	$ 55.08
Weighted Average Grant Date Fair Value, Vested	55.87
Weighted Average Grant Date Fair Value, Forfeited	69.86
Weighted Average Grant Date Fair Value, Reduction due to the achievement of lower than maximum performance milestones	60.31
Weighted Average Grant Date Fair Value, Unvested at end of period	$ 71.59	$ 59.15

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Number of Units
Number of Units, Unvested at beginning of period	5.2
Number of Units, Granted	2.8
Number of Units, Vested	(2.5)
Number of Units, Forfeited	(0.5)
Number of Units, Unvested at end of period	5	5.2
Weighted Average Grant Date Fair Value (in dollars)
Weighted Average Grant Date Fair Value, Unvested at beginning of period	$ 63.80
Weighted Average Grant Date Fair Value, Granted	74.94	$ 67.56	$ 55.55
Weighted Average Grant Date Fair Value, Vested	64.05
Weighted Average Grant Date Fair Value, Forfeited	65.93
Weighted Average Grant Date Fair Value, Unvested at end of period	$ 69.64	$ 63.80

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party		$ 4	$ 2
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	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 4,129	$ 4,078	$ 4,006	$ 3,912	$ 3,828	$ 3,766	$ 3,670	$ 3,546	$ 16,125	$ 14,810	$ 13,487
Income from operations	$ 693	$ 745	$ 670	$ 693	$ 657	$ 648	$ 606	$ 570	2,801	2,481	2,289
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Less: unallocated costs									2,130	2,115	1,910
Operating Segments [Member]
Segment Reporting Information [Line Items]
Income from operations									4,931	4,596	4,199
Operating Segments [Member] | Financial Services
Segment Reporting Information [Line Items]
Revenues									5,845	5,636	5,366
Income from operations									1,757	1,771	1,707
Operating Segments [Member] | Healthcare
Segment Reporting Information [Line Items]
Revenues									4,668	4,263	3,871
Income from operations									1,431	1,301	1,153
Operating Segments [Member] | Products and Resources
Segment Reporting Information [Line Items]
Revenues									3,415	3,040	2,660
Income from operations									1,043	923	851
Operating Segments [Member] | Communications, Media and Technology
Segment Reporting Information [Line Items]
Revenues									2,197	1,871	1,590
Income from operations									$ 700	$ 601	$ 488

Segment Information (Revenues A

Segment Information (Revenues And Long-Lived Assets By Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Geographic Areas, Revenues
Revenues	$ 4,129	$ 4,078	$ 4,006	$ 3,912	$ 3,828	$ 3,766	$ 3,670	$ 3,546	$ 16,125	$ 14,810	$ 13,487
Geographic Areas, Long-Lived Assets
Long-lived assets	1,394				1,324				1,394	1,324	1,311
North America [Member]
Geographic Areas, Revenues
Revenues									12,293	11,450	10,546
Geographic Areas, Long-Lived Assets
Long-lived assets	436				360				436	360	279
United Kingdom [Member]
Geographic Areas, Revenues
Revenues									1,274	1,150	1,176
Europe, excluding United Kingdom [Member]
Geographic Areas, Revenues
Revenues									1,563	1,248	969
Europe [Member]
Geographic Areas, Revenues
Revenues									2,837	2,398	2,145
Geographic Areas, Long-Lived Assets
Long-lived assets	105				63				105	63	52
Rest of World [Member]
Geographic Areas, Revenues
Revenues									995	962	796
Geographic Areas, Long-Lived Assets
Long-lived assets	$ 853				$ 901				$ 853	$ 901	$ 980

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Summary Of Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount									$ 20	$ 40
Revenues	$ 4,129	$ 4,078	$ 4,006	$ 3,912	$ 3,828	$ 3,766	$ 3,670	$ 3,546	16,125	14,810	$ 13,487
Cost of revenues (exclusive of depreciation and amortization expense shown separately below)	2,540	2,480	2,417	2,401	2,360	2,337	2,261	2,194	9,838	9,152	8,108
Selling, general and administrative expenses	776	734	805	711	700	674	709	686	3,026	2,769	2,731
Depreciation and amortization expense	120	119	114	107	111	107	94	96	460	408	359
Income from operations	693	745	670	693	657	648	606	570	2,801	2,481	2,289
Net income	$ 648	$ 477	$ 456	$ 520	$ (18)	$ 495	$ 470	$ 557	$ 2,101	$ 1,504	$ 1,553
Basic earnings per share	$ 1.12	$ 0.82	$ 0.78	$ 0.89	$ (0.03)	$ 0.84	$ 0.80	$ 0.92	$ 3.61	$ 2.54	$ 2.56
Diluted earnings per share	$ 1.12	$ 0.82	$ 0.78	$ 0.88	$ (0.03)	$ 0.84	$ 0.80	$ 0.92	3.60	2.53	$ 2.55
Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Per Share Amount									$ 0.03	$ 0.07

Valuation And Qualifying Acco_2

Valuation And Qualifying Accounts (Valuation And Qualifying Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable Allowance For Doubtful Accounts [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 65	$ 48	$ 39
Charged to Costs and Expenses	13	15	12
Charged to Other Accounts	0	3	0
Deductions/Other	0	1	3
Balance at End of Period	78	65	48
Warranty Accrual [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	30	26	24
Charged to Costs and Expenses	32	30	28
Charged to Other Accounts	0	0	0
Deductions/Other	30	26	26
Balance at End of Period	32	30	26
Valuation Allowance - Deferred Income Tax Assets [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	10	10	10
Charged to Costs and Expenses	1	0	0
Charged to Other Accounts	0	0	0
Deductions/Other	0	0	0
Balance at End of Period	$ 11	$ 10	$ 10

Subsequent Events (Details)

Subsequent Events (Details)	Feb. 04, 2019$ / shares
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividends declared per common share	$ 0.20