ExlService (EXLS) 10-K 28 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 25, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	ExlService Holdings, Inc.
Entity Central Index Key	1,297,989
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Trading Symbol	EXLS
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		34,323,339
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Public Float			$ 1,867,374,591

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 95,881	$ 86,795
Short-term investments	184,489	178,479
Restricted cash	5,608	3,674
Accounts receivable, net	164,752	135,705
Prepaid expenses	11,326	9,781
Advance income tax, net	9,639	8,801
Other current assets	28,240	29,582
Total current assets	499,935	452,817
Property and equipment, net	73,510	66,757
Restricted cash	2,642	3,808
Deferred tax assets, net	6,602	9,280
Intangible assets, net	95,495	48,958
Goodwill	349,984	204,481
Other assets	31,015	36,369
Investment in equity affiliate	2,753	3,000
Total assets	1,061,936	825,470
Current liabilities:
Accounts payable	5,653	5,918
Current portion of long-term borrowings	21,423	10,318
Deferred revenue	7,722	10,716
Accrued employee costs	54,893	55,664
Accrued expenses and other current liabilities	64,169	61,366
Income taxes payable	1,012	0
Current portion of capital lease obligations	223	267
Total current liabilities	155,095	144,249
Long term borrowings	263,241	50,391
Capital lease obligations, less current portion	315	331
Income taxes payable	0	13,557
Deferred tax liabilities, net	8,445	695
Other non-current liabilities	16,521	16,202
Total liabilities	443,617	225,425
Commitments and contingencies (Refer to Note 26)
Preferred stock, $0.001 par value; 15,000,000 shares authorized, none issued	0	0
ExlService Holdings, Inc. Stockholders’ equity:
Common stock, $0.001 par value; 100,000,000 shares authorized, 37,850,544 shares issued and 34,222,476 shares outstanding as of December 31, 2018 and 36,790,751 shares issued and 33,888,733 shares outstanding as of December 31, 2017	38	37
Additional paid-in capital	364,179	322,246
Retained earnings	484,244	427,064
Accumulated other comprehensive loss	(83,467)	(45,710)
Total including shares held in treasury	764,994	703,637
Less: 3,628,068 shares as of December 31, 2018 and 2,902,018 shares as of December 31, 2017, held in treasury, at cost	(146,925)	(103,816)
Stockholders' equity	618,069	599,821
Non-controlling interest	250	224
Total equity	618,319	600,045
Total liabilities and equity	$ 1,061,936	$ 825,470

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock shares authorized (in shares)	15,000,000	15,000,000
Preferred stock shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	100,000,000	100,000,000
Common stock shares issued (in shares)	37,850,544	36,790,751
Common stock shares outstanding (in shares)	34,222,476	33,888,733
Treasury shares held (in shares)	3,628,068	2,902,018

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($)		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Income Statement [Abstract]
Revenues, net		$ 883,112,000		$ 762,310,000	[1]	$ 685,988,000	[1]
Cost of revenues		584,855,000	[1],[2]	495,142,000	[1],[2]	447,718,000
Gross profit	[2]	298,257,000		267,168,000	[1]	238,270,000	[1]
Operating expenses:
General & administrative expenses		116,202,000	[1]	102,515,000	[1]	88,616,000
Selling & marketing expenses		63,612,000	[1]	53,379,000	[1]	50,579,000
Depreciation and amortization		48,566,000		38,549,000	[1]	34,580,000
Impairment charges		20,056,000		0	[1],[3]	0	[1],[3]
Total operating expenses	[1]	248,436,000		194,443,000		173,775,000
Income from operations		49,821,000		72,725,000	[1]	64,495,000	[1]
Foreign exchange gain, net		4,787,000		2,839,000	[1]	5,597,000	[1]
Interest expense		(7,227,000)		(1,889,000)	[1]	(1,343,000)	[1]
Other income, net		12,989,000	[1]	11,359,000	[4]	15,135,000	[4]
Income before income tax expense		60,370,000		85,034,000	[1]	83,884,000	[1]
Income tax expense		3,397,000		36,146,000	[1]	22,151,000	[1]
Loss from equity-method investment		247,000		0	[1],[3]	0	[1],[3]
Net income attributable to ExlService Holdings, Inc. stockholders		$ 56,726,000		$ 48,888,000	[1],[3]	$ 61,733,000	[1],[3]
Earnings per share attributable to ExlService Holdings, Inc. stockholders:
Basic (in dollars per share)		$ 1.65		$ 1.44	[1]	$ 1.84	[1]
Diluted (in dollars per share)		$ 1.62		$ 1.39	[1]	$ 1.79	[1]
Weighted-average number of shares used in computing earnings per share:
Basic (in shares)		34,451,008		33,897,916	[1]	33,566,367	[1]
Diluted (in shares)		35,030,984		35,110,210	[1]	34,563,319	[1]
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[2]	Exclusive of depreciation and amortization.
[3]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[4]	These are reclassified to net income and are included in other income, net in the consolidated statements of income. Refer to Note 21 to the consolidated financial statements.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income		$ 56,726	$ 48,888	[1],[2]	$ 61,733	[1],[2]
Other comprehensive (loss)/income:
Unrealized (loss)/gain on effective cash flow hedges, net of taxes ($3,888), $5,821 and $1,734, respectively		(10,031)	13,981		3,395
Foreign currency translation (loss)/gain		(25,700)	18,894		(9,236)
Retirement benefits, net of taxes $44, $164 and ($204), respectively		338	1,109		(439)
Reclassification adjustments
(Gain)/loss on cash flow hedges, net of taxes ($915), ($2,110) and ($1,190), respectively(1)	[3]	(2,234)	(4,789)		(1,479)
Retirement benefits, net of taxes ($23), $104 and $63, respectively(2)	[4]	(130)	152		27
Total other comprehensive (loss)/income		(37,757)	29,347		(7,732)
Total comprehensive income		$ 18,969	$ 78,235		$ 54,001
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[3]	These are reclassified to net income and are included either in cost of revenue or operating expenses, as applicable in the consolidated statements of income. Refer to Note 18 to the consolidated financial statements.
[4]	These are reclassified to net income and are included in other income, net in the consolidated statements of income. Refer to Note 21 to the consolidated financial statements.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Unrealized gain/(loss) on effective cash flow hedges, tax		$ (3,888)	$ 5,821	$ 1,734
Retirement benefits, tax		44	164	(204)
Reclassification adjustment, realized (gain)/loss on cash flow hedges, tax	[1]	(915)	(2,110)	(1,190)
Reclassification adjustment, retirement benefits, tax	[2]	$ (23)	$ 104	$ 63
[1]	These are reclassified to net income and are included either in cost of revenue or operating expenses, as applicable in the consolidated statements of income. Refer to Note 18 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Thousands		Total		Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income/(Loss)	Treasury Stock	Non - Controlling Interest
Beginning balance (in shares) at Dec. 31, 2015				34,781,201				1,689,978
Beginning balance at Dec. 31, 2015		$ 465,771		$ 35	$ 254,052	$ 320,989	$ (67,325)	$ (42,159)	$ 179
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued, stock-based compensation plans (in shares)				918,618
Stock issued, stock-based compensation plans		6,499		$ 1	6,498
Stock issued, business acquisition	[1]	0
Stock-based compensation		19,770			19,770
Excess tax benefit from stock based compensation		4,326			4,326
Acquisition of treasury stock (in shares)								(381,732)
Acquisition of treasury stock		(18,203)						$ (18,203)
Non-controlling interest		14							14
Other comprehensive loss		(7,732)					(7,732)
Net income		61,733	[1],[2]			61,733
Ending balance (in shares) at Dec. 31, 2016				35,699,819				2,071,710
Ending balance at Dec. 31, 2016		532,178		$ 36	284,646	382,722	(75,057)	$ (60,362)	193
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact on adoption of accounting standard update	[3]	1,453			5,999	(4,546)
Beginning balance, adjusted		533,631		$ 36	290,645	378,176	(75,057)	$ (60,362)	193
Stock issued, stock-based compensation plans (in shares)				1,090,932
Stock issued, stock-based compensation plans		8,561		$ 1	8,560
Stock issued, business acquisition	[1]	0
Stock-based compensation		23,041			23,041
Acquisition of treasury stock (in shares)								(830,308)
Acquisition of treasury stock		(43,454)						$ (43,454)
Non-controlling interest		31							31
Other comprehensive loss		29,347					29,347
Net income		$ 48,888	[1],[2]			48,888
Ending balance (in shares) at Dec. 31, 2017		33,888,733		36,790,751				2,902,018
Ending balance at Dec. 31, 2017		$ 600,045		$ 37	322,246	427,064	(45,710)	$ (103,816)	224
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact on adoption of accounting standard update	[4]	454				454
Beginning balance, adjusted		600,499		$ 37	322,246	427,518	(45,710)	$ (103,816)	224
Stock issued, stock-based compensation plans (in shares)				990,334
Stock issued, stock-based compensation plans		1,398		$ 1	1,397
Stock issued business acquisition (in shares)				69,459
Stock issued, business acquisition		4,080			4,080
Stock-based compensation		23,901			23,901
Acquisition of treasury stock (in shares)								(726,050)
Acquisition of treasury stock		(43,109)						$ (43,109)
Allocation of equity component related to the convertible senior notes, net of tax and issuance costs		12,555			12,555
Non-controlling interest		26							26
Other comprehensive loss		(37,757)					(37,757)
Net income		$ 56,726				56,726
Ending balance (in shares) at Dec. 31, 2018		34,222,476		37,850,544				3,628,068
Ending balance at Dec. 31, 2018		$ 618,319		$ 38	$ 364,179	$ 484,244	$ (83,467)	$ (146,925)	$ 250
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[3]	Refer to Note 2(p) to the consolidated financial statements for details.
[4]	Refer to Note 2(d) to the consolidated financial statements for details.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Cash flows from operating activities:
Net income		$ 56,726,000	$ 48,888,000	[1],[2]	$ 61,733,000	[1],[2]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		48,719,000	38,984,000	[1]	34,580,000	[1]
Stock-based compensation expense		23,901,000	23,041,000	[1]	19,770,000	[1]
Unrealized gain on short term investments		(7,696,000)	0	[1]	0	[1]
Unrealized foreign exchange (gain)/loss, net		(8,620,000)	1,523,000	[1]	(1,001,000)	[1]
Deferred income tax (benefit)/expense		(625,000)	731,000	[1]	(3,384,000)	[1]
Impairment charges		20,056,000	0	[1],[2]	0	[1],[2]
Excess tax benefit from stock-based compensation		0	0	[1]	(4,326,000)	[1]
Change in fair value of earn-out consideration		0	0	[1]	(4,060,000)	[1]
Allowance for doubtful accounts receivable		(573,000)	2,816,000	[1]	0	[1]
Loss from equity-method investment		247,000	0	[1],[2]	0	[1],[2]
Others, net		903,000	252,000	[1]	(107,000)	[1]
Change in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable		(10,046,000)	(20,482,000)	[1]	(18,062,000)	[1]
Prepaid expenses and other current assets		(4,509,000)	218,000	[1]	(5,421,000)	[1]
Accounts payable		(360,000)	1,706,000	[1]	(2,628,000)	[1]
Deferred revenue		(4,929,000)	(6,625,000)	[1]	5,726,000	[1]
Accrued employee costs		1,272,000	6,391,000	[1]	5,304,000	[1]
Accrued expenses and other liabilities		(1,084,000)	6,903,000	[1]	9,080,000	[1]
Advance income tax, net		(14,147,000)	11,037,000	[1]	437,000	[1]
Other assets		(6,800,000)	(2,224,000)	[1]	4,754,000	[1]
Net cash provided by operating activities	[1]	92,435,000	113,159,000		102,395,000
Cash flows from investing activities:
Purchase of property and equipment		(40,437,000)	(35,154,000)	[1]	(25,850,000)	[1]
Investment in equity affiliate		0	(3,000,000)	[1]	0	[1]
Business acquisition (net of cash acquired)		(231,829,000)	(23,300,000)	[1]	(28,666,000)	[1]
Purchase of investments		(133,434,000)	(402,721,000)	[1]	(182,471,000)	[1]
Proceeds from redemption of investments		128,208,000	241,439,000	[1]	182,320,000	[1]
Net cash used for investing activities		(277,492,000)	(222,736,000)	[1]	(54,667,000)	[1]
Cash flows from financing activities:
Principal payments on capital lease obligations		(152,000)	(174,000)	[1]	(348,000)	[1]
Proceeds from borrowings		246,614,000	60,574,000	[1]	0	[1]
Repayments of borrowings		(155,209,000)	(45,192,000)	[1]	(25,000,000)	[1]
Proceeds from convertible notes		149,000,000	0	[1]	0	[1]
Payment of debt issuance costs		(762,000)	(790,000)	[1]	0	[1]
Acquisition of treasury stock		(43,109,000)	(43,454,000)	[1]	(18,203,000)	[1]
Proceeds from exercise of stock options		1,397,000	8,561,000	[1]	6,499,000	[1]
Excess tax benefit from stock-based compensation		0	0	[1]	4,326,000	[1]
Net cash provided by/(used for) financing activities		197,779,000	(20,475,000)	[1]	(32,726,000)	[1]
Effect of exchange rate changes on cash, cash equivalents and restricted cash	[1]	(2,868,000)	3,935,000		(5,122,000)
Net increase/(decrease) in cash, cash equivalents and restricted cash(1)	[1]	9,854,000	(126,117,000)		9,880,000
Cash, cash equivalents and restricted cash - beginning of year	[1]	94,277,000	220,394,000		210,514,000
Cash, cash equivalents and restricted cash - end of year	[1]	104,131,000	94,277,000		220,394,000
Supplemental disclosure of cash flow information:
Restricted common stock issued for business acquisition		4,080,000	0	[1]	0	[1]
Cash paid for interest		4,725,000	1,122,000	[1]	1,178,000	[1]
Cash paid for taxes, net of refund		18,508,000	19,128,000	[1]	15,667,000	[1]
Assets acquired under capital lease		$ 277,000	$ 301,000	[1]	$ 334,000	[1]
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Organization

Organization	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization ExlService Holdings, Inc. (“ExlService Holdings”) is organized as a corporation under the laws of the state of Delaware. ExlService Holdings, together with its subsidiaries and affiliates (collectively, the “Company”), operates in the Business Process Management (“BPM”) industry providing operations management services and analytics services that help businesses enhance revenue growth and improve profitability. Using its proprietary platforms, methodologies and tools, the Company looks deeper to help companies improve global operations, enhance data-driven insights, increase customer satisfaction, and manage risk and compliance. The Company’s clients are located principally in the United States of America (“U.S.”) and the United Kingdom (“U.K.”).

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Basis of Preparation and Principles of Consolidation The consolidated financial statements have been prepared in conformity with United States generally accepted accounting principles (“US GAAP”). The accompanying financial statements have been prepared on a consolidated basis and reflect the financial statements of ExlService Holdings and all of its subsidiaries and includes the Company's share in the results of its associates. The standalone financial statements of subsidiaries are fully consolidated on a line-by-line basis. Intra-group balances and transactions, and income and expenses arising from intra-group transactions, are eliminated while preparing those financial statements. Accounting policies of the respective individual subsidiary and associate are aligned wherever necessary, so as to ensure consistency with the accounting policies that are adopted by the Company under US GAAP. The Company’s investments in equity affiliates are initially recorded at cost and any excess cost over proportionate share of the fair value of the net assets of the investee at the acquisition date is recognized as goodwill. The proportionate share of net income or loss of the investee is recognized in the consolidated statements of income. Non-controlling interest is the equity in a subsidiary not attributable, directly or indirectly, to the parent and it represents the minority partner’s interest in the operations of ExlService Colombia S.A.S. Non-controlling interest consists of the amount of such interest at the date of obtaining control over the subsidiary, and the non-controlling interest's share of changes in equity since that date. The non-controlling interests in the operations for the years ended December 31, 2018, 2017 and 2016 were insignificant and is included under general and administrative expenses in the consolidated statements of income. (b) Use of Estimates The preparation of the consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the consolidated statements of income during the reporting period. Although these estimates are based on management’s best assessment of the current business environment, actual results may be different from those estimates. The significant estimates and assumptions that affect the consolidated financial statements include, but are not limited to, allowance for doubtful receivables, expected recoverability from customers with contingent fee arrangements, recoverability of dues from statutory authorities, assets and obligations related to employee benefit plans, deferred tax valuation allowances, income-tax uncertainties and other contingencies, valuation of derivative financial instruments, assumptions used to calculate stock-based compensation expense, depreciation and amortization periods, purchase price allocation, recoverability of long-term assets including goodwill and intangibles, and estimated costs to complete fixed price contracts. (c) Foreign Currency Translation The functional currency of each entity in the Company is its respective local country currency which is also the currency of the primary economic environment in which it operates except for the entities in Mauritius which use the U.S. dollar as its functional currency. Transactions in foreign currencies are initially recorded into functional currency at the rates of exchange prevailing on the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are remeasured into functional currency at the rates of exchange prevailing at the balance sheet date. Non-monetary assets and liabilities are remeasured to the functional currency of the subsidiary at historical exchange rates. All transaction foreign exchange gains and losses are recorded in the accompanying consolidated statements of income. The assets and liabilities of the subsidiaries for which the functional currency is other than the U.S. dollar are translated into U.S. dollars, the reporting currency, at the rate of exchange prevailing on the balance sheet date. Revenues and expenses are translated into U.S. dollars at the exchange rates prevailing on the last business day of each month, which approximates the average monthly exchange rate. Resulting translation adjustments are included in accumulated other comprehensive loss in the consolidated balance sheet. (d) Revenue Recognition Revenue is recognized when services are provided to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for our services. Revenue is measured based on consideration specified in a contract with a customer and excludes discounts and amounts collected on behalf of third parties. The Company recognizes revenue when it satisfies a performance obligation by providing services to a customer. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by the Company from a customer, are excluded from revenue. Adoption of Financial Accounting Standards Board Accounting Standards Update (“ASU”) No. 2014-09 Topic 606, Revenue from Contracts with Customers (“Topic 606”) On January 1, 2018, the date of initial application, the Company adopted Topic 606 using the modified retrospective method by recognizing the cumulative effect of initially applying Topic 606 as an adjustment to the opening balance of retained earnings, resulting in an increase of $454 , primarily due to new contract acquisition costs. The initial application scopes in those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning January 1, 2018 are presented under Topic 606. The prior period consolidated financial statement have not been retrospectively adjusted and continue to be reported under the accounting standards in effect for those periods. The key area impacted upon adoption of Topic 606 relates to the accounting for sales commissions costs. Specifically, under Topic 606 a portion of sales commission costs have been recorded as an asset and recognized as an operating expense on a straight-line basis over the expected period of benefit. Prior to adoption, the Company was expensing sales commission costs as incurred. Nature of services The Company derives its revenues from operations management and analytics services. The Company operates in the business process management (“BPM”) industry providing operations management and analytics services helping businesses enhance revenue growth and improve profitability. The Company provides BPM or “operations management” services, which typically involve transfer to the Company of business operations of a client, after which it administers and manages those operations for its client on an ongoing basis. The Company also provides industry-specific digital transformational services related to operations management services, and analytics services that focus on driving improved business outcomes for clients by generating data-driven insights across all parts of their business. The Company also provides care optimization and reimbursement optimization services, for its clients through its healthcare analytics solutions and services. The Company offers integrated solutions to help its clients with cost containment by leveraging technology platforms, customizable and configurable analytics and expertise in healthcare reimbursements to help clients enhance their claims payment accuracy. Arrangements with Multiple Performance Obligations The Company’s contracts with customers do not generally bundle different services together except for software and related services contracts, which are not significant, involving implementation services and post contract maintenance services. In such software and related services contracts, revenue is allocated to each performance obligation based on the relative standalone selling price. A separate contract is generally drafted for each type of service sold, even if to the same customer. The typical length of a contract is 3 to 5 years for our operations management contracts. Type of Contracts i. a) Revenues under time-and-material, transaction and outcome-based contracts are recognized as the services are performed. When the terms of the client contract specify service level parameters that must be met (such as turnaround time or accuracy), the Company monitors such service level parameters to determine if any service credits or penalties have been incurred. Revenues are recognized net of any penalties or service credits that are due to a client. b) In respect of arrangements involving subcontracting, in part or whole of the assigned work, the Company evaluates revenues to be recognized based on guidance on “Principal versus agent considerations” in Topic 606. ii. Revenues for Company’s fixed-price contracts are recognized using the time-elapsed output method because the Company transfers control evenly during execution of its projects. Determining a measure of progress requires management to make judgments that affect the timing of revenue recognized. The Company regularly monitors its estimates for progress on completion of a project and records changes in the period in which a change in an estimate is determined. If a change in an estimate results in a projected loss on a project, such loss is recognized in the period in which it is identified. iii. Revenues from the Company's software and related services contracts, which are not significant, are primarily related to maintenance renewals or incremental license fees for additional users. Maintenance revenues are generally recognized on a straight-line basis over the annual contract term. Fees for incremental license fees without any associated services are recognized upon delivery of the related incremental license. iv. Revenues from reimbursement optimization services having contingent fee arrangements are recognized by the Company at the point in time when a performance obligation is satisfied, which is when it identifies an overpayment claim and the overpaid amount is acknowledged by its customers. In such contracts, the Company’s consideration is contingent upon the actual collections made by its customers and subsequent potential retractions from providers. Based on guidance on “variable consideration” in Topic 606, the Company uses its historical experience and projections to determine the expected recoveries from its customers and recognizes revenue based upon such expected recoveries. Any adjustment required due to change in estimates are recorded in the period in which such changes are identified. Unbilled receivables represent revenues recognized for services rendered between the last billing date and the balance sheet date. Unbilled receivables also include revenues recognized from reimbursement optimization services when the Company identifies an overpayment claim and the same is acknowledged by its customers, however not invoiced at the balance sheet date. Accordingly, amounts for services that the Company has performed and for which an invoice has not yet been issued to the customers are presented as a part of contract assets as accounts receivable. The Company recognizes billings in excess of revenues recognized as deferred revenues until revenue recognition criteria as per ASC 606 is met. Client prepayments (even if nonrefundable) are deferred and recognized over future periods as services are delivered or performed. The company also has deferred revenue attributable to certain process transition activities, with respect to its customers where such activities do not represent separate performance obligations. Revenues related to such transition activities are contract liabilities classified under “Deferred Revenue” and “Other Non-current liabilities”, based on their expected recognition, in the Company's consolidated balance sheets and subsequently recognized ratably over the period in which the related services are performed. Costs related to transition activities are contract fulfillment costs, and thereby classified under “Other Current Assets” and “Other Assets” in the consolidated balance sheets, and are recognized ratably over the estimated expected period of benefit, under Cost of Revenues in the consolidated statements of income. Other incremental and direct costs incurred for acquiring contracts, such as sales commissions are contract acquisition costs and thereby classified under “Other Current Assets” and “Other Assets” in the consolidated balance sheets. Such costs are amortized over the expected period of benefit and recorded under Selling and marketing expenses in the consolidated statements of income. Any upfront payments made to customers are contract assets and classified under “Other Current Assets and Other Assets” in the consolidated balance sheets. Such costs are amortized over the expected period of benefit and are recorded as an adjustment to transaction price and reduced from revenues. Reimbursements of out-of-pocket expenses received from clients are included as part of revenues. Reimbursements of out-of-pocket expenses included in revenues were $20,796 , $17,982 and $21,812 for the years ended December 31, 2018, 2017 and 2016, respectively. Payment terms All contracts entered into by the Company specify the payment terms and are defined for each contract separately. Usual payment terms range between 30 - 60 days. The Company does not have any extended payment terms clauses in existing contracts. At times, the Company enters into fixed price contracts and software licenses involving significant implementation wherein the milestones are defined such that the Company can recover the costs with a reasonable margin. Variable Consideration Variability in the transaction price arises primarily due to service level agreements, cost of living adjustments, and pre-payment and volume discounts. The Company considers its experience with similar transactions and expectations regarding the contract in estimating the amount of variable consideration that should be recognized during a period. The Company believes that the expected value method is most appropriate for determining the variable consideration since the company has large number of contracts with similar nature of transactions/services. Allocation of transaction price to performance obligations The transaction price is allocated to performance obligations on a relative standalone selling price basis. Standalone selling prices are estimated by reference to the total transaction price less the sum of the observable standalone selling prices of other goods or services promised in the contract. In assessing whether to allocate variable consideration to a specific part of the contract, the Company considers the nature of the variable payment and whether it relates specifically to its efforts to satisfy a specific part of the contract. Practical expedients and exemptions The Company does not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which the Company recognizes revenue at the amount to which the Company has the right to invoice for services performed. (e) Cash and Cash Equivalents and Restricted Cash The Company considers all highly liquid investments purchased with an original maturity of ninety days or less to be cash equivalents. Pursuant to the Company’s investment policy, surplus funds are invested in highly-rated debt mutual funds, money market accounts and time deposits to reduce its exposure to market risk with regard to these funds. Restricted cash represents amounts on deposit with banks against bank guarantees issued through banks in favor of relevant statutory authorities for equipment imports, deposits for obtaining indirect tax registration and for demands against pending income tax assessments (refer Note 8 to the consolidated financial statements for details). These deposits with banks have maturity dates after December 31, 2019. Restricted cash presented under current assets represents funds held on behalf of clients in dedicated bank accounts. Effective January 1, 2018, the Company adopted ASU No. 2016-18, Statements of Cash Flows ("Topic 230"), Restricted Cash . Pursuant to this adoption, for purposes of the statements of cash flows, the Company includes in its cash and cash-equivalent balances those amounts that have been classified as restricted cash and restricted cash equivalents for each period presented. (f) Investments The Company’s investments consist of time deposits with financial institutions which are valued at cost and approximate fair value. Interest earned on such investments is included in interest income. Investments with original maturities greater than ninety days but less than twelve months are classified as short-term investments. Investments with maturities greater than twelve months from the balance sheet date are classified as long-term investments. The Company's mutual fund investments are in debt and money market funds which invest in instruments of various maturities in India. These investments are accounted for in accordance with the fair value option under Financial Accounting Standard Board Accounting Standards Codification (“ASC”) Topic 825, Financial Instruments , (“Topic 825”) and change in fair value is included in interest and other income. The fair value is represented by original cost on the acquisition date and the net asset value (“NAV”) as quoted, at each reporting period. Gain or loss on the disposal of these investments is calculated using the weighted average cost of the investments sold or disposed and is included in interest and other income. (g) Accounts Receivable Accounts receivable are recorded net of allowances for doubtful accounts. Allowances for doubtful accounts are established through the evaluation of the accounts receivable aging and prior collection experience, current market conditions, clients’ financial condition and the amounts of receivables in dispute to ascertain the ultimate collectability of these receivables. As of December 31, 2018 and 2017 , the Company had $956 and $2,923 , respectively, of allowance for doubtful accounts. Accounts receivable include unbilled accounts receivable which represent revenues on contracts to be billed, in subsequent periods, as per the terms of the related contracts. As of December 31, 2018 and 2017 , the Company had $63,952 and $49,125 , respectively, of unbilled accounts receivable. (h) Property and equipment Property and equipment are stated at cost less accumulated depreciation and impairment. Equipment held under capital leases are capitalized at the commencement of the lease at the lower of present value of minimum lease payments at the inception of the leases or its fair value. Advances paid towards acquisition of property and equipment and the cost of property and equipment not yet placed in service before the end of the reporting period are classified as capital work in progress. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Depreciation and amortization on equipment held under capital leases and leasehold improvements are computed using the straight-line method over the shorter of the asset's estimated useful lives or the lease term. The Company reviews property and equipment for impairment whenever events or changes in circumstances indicate that the related carrying amounts may not be recoverable. Useful Lives Assets: Network equipment and computers 3-5 Software 3-5 Leasehold improvements 3-8 Office furniture and equipment 3-8 Motor vehicles 2-5 Buildings 30 (i) Software Development Costs The Company capitalizes certain costs related to the development or enhancements to existing software products to be sold, leased or otherwise marketed and / or used for internal use. The Company begins to capitalize costs to develop or enhance software when planning stage efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and the software will be used as intended. Costs incurred prior to meeting these criteria, together with costs incurred for training and maintenance, are expensed as incurred and recorded within “general and administrative expenses” in the Company’s consolidated statements of income. The Company exercises judgment in determining the point at which various projects may be capitalized, in assessing the ongoing value of the capitalized costs, and in determining the estimated useful lives over which the costs are amortized. Annual amortization of internally developed software products is the greater of the amount computed using the ratio that current gross revenues for a product bear to the total of current and anticipated future gross revenues for that product or the straight-line method over the remaining estimated economic life of the software product, generally estimated to be up to 5 years from the date the product became available for use. (j) Business Combinations, Goodwill and Other Intangible Assets ASC Topic 805, Business Combinations, requires that the acquisition method of accounting be used for all business combinations. The guidance specifies criteria as to intangible assets acquired in a business combination that must be recognized and reported separately from goodwill. Contingent consideration is recognized at its fair value on the acquisition date. A liability resulting from contingent consideration is re-measured to fair value as of each reporting date until the contingency is resolved. Changes in fair value are recognized in earnings. These fair value measurements represent Level 3 measurements as they are based on significant inputs not observable in the market. Under ASC 350 all assets and liabilities of the acquired businesses, including goodwill, are assigned to reporting units. Acquisition related costs are expensed as incurred under general and administrative expenses. Goodwill represents the cost of the acquired businesses in excess of the fair value of identifiable tangible and intangible net assets purchased in a business combination. Goodwill is not amortized but is tested for impairment at least on an annual basis, relying on a number of factors including operating results, business plans and estimated future cash flows of the reporting units to which it is assigned. The Company undertakes studies to determine the fair values of assets and liabilities acquired and allocate purchase consideration to assets and liabilities, including property and equipment, goodwill and other identifiable intangibles. The Company examines the carrying value of the goodwill annually in the fourth quarter, or more frequently, as circumstances warrant, to determine whether there are any impairment losses. The Company tests for goodwill impairment at the reporting unit level, as that term is defined in US GAAP. Refer to Note 10 for discussion of the Company's goodwill impairment testing. As stated in Note 2(x), we adopted ASU No. 2017-04, Simplifying the Test for Goodwill Impairment, during 2018 in conjunction with our goodwill impairment assessment. The quantitative goodwill impairment test involves a comparison of the fair value of a reporting unit with its carrying amount. The fair value of the reporting unit is measured using the income approach. Under the income approach, fair value is determined based on the present value of estimated future cash flows, discounted at an appropriate risk-adjusted rate. The Company uses its internal forecasts to estimate future cash flows and include an estimate of long-term future growth rates based on its most recent views of the long-term outlook for each business. Actual results may differ from those assumed in our forecasts. Discount rate assumptions are based on an assessment of the risk inherent in the future cash flows of the respective reporting units. The discount rate is mainly based on judgment of the specific risk inherent within each reporting unit. The variables within the discount rate, many of which are outside of the Company’s control, provide the Company’s best estimate of all assumptions applied within the DCF model. Determining fair value requires the exercise of significant judgment, including assumptions about appropriate discount rates, perpetual growth rates and the amount and timing of expected future cash flows. There can be no assurance that operations will achieve the future cash flows reflected in the projections. If the carrying amount of the reporting unit exceeds its fair value, an impairment loss shall be recognized, if any, in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. Goodwill of a reporting unit is tested for impairment annually or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit below its carrying amount. Intangible assets acquired in a business combination are initially valued and recognized at fair market value using generally accepted valuation methods appropriate for the type of intangible asset. Intangible assets with definite lives are amortized over the estimated useful lives and are reviewed for impairment, if indicators of impairment arise. The evaluation of impairment is based upon a comparison of the carrying amount of the intangible asset to its fair value, which is calculated using the estimated future undiscounted net cash flows expected to be generated by the asset. If the fair value of the intangible assets is less than the carrying amount of the asset, the asset is considered impaired and an impairment expense is recognized equal to any shortfall in the current period. The Company’s definite lived intangible assets are amortized over their estimated useful lives as listed below using a straight-line method: Customer relationships 3-15 years Leasehold benefits 3-8 years Developed technology 5-10 years Non-compete agreements 1-5 years Trade names and trademarks 3-10 years (k) Investment in Equity Affiliate Investments in equity affiliate are initially recorded at cost and any excess cost over proportionate share of the fair value of the net assets of the investee at the acquisition date is recognized as goodwill. The proportionate share of net income or loss of the investee is recognized in the consolidated statements of income. The Company periodically reviews the carrying value of its investment to determine if there has been any other than temporary decline in carrying value. The investment balance for an investee is increased or decreased for cash contribution and distributions to or from, respectively. (l) Impairment of Long-lived Assets Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Such assets are required to be tested for impairment if the carrying amount of the assets is higher than the future undiscounted net cash flows expected to be generated from the assets. Determining whether an impairment has occurred typically requires various estimates and assumptions, including determining which undiscounted cash flows are directly related to the potentially impaired asset, the useful life over which cash flows will occur, their amount, and the asset’s residual value, if any. In turn, measurement of an impairment loss requires a determination of fair value, which is based on the best information available. The Company derives the required undiscounted cash flow estimates from its historical experience and its internal business plans. To determine fair value, the Company uses its internal cash flow estimates discounted at an appropriate discount rate and independent appraisals, as appropriate. The impairment amount to be recognized is measured as the amount by which the carrying value of the assets exceeds their fair value. The Company determines fair value by using a discounted cash flow approach. (m) Derivative Financial Instruments In the normal course of business, the Company uses derivative instruments for the purpose of mitigating the exposure from foreign currency fluctuation risks associated with forecasted transactions denominated in certain foreign currencies and to minimize earnings and cash flow volatility associated with changes in foreign currency exchange rates, and not for speculative trading purposes. These derivative contracts are purchased within the Company’s policy and are with counterparties that are highly rated financial institutions. The Company hedges forecasted transactions that are subject to foreign exchange exposure with foreign currency exchange contracts that qualify as cash flow hedges. Changes in the fair value of these cash flow hedges are recorded as a component of accumulated other comprehensive income/(loss), net of tax, until the hedged transactions occurs. The Company early adopted ASU No. 2017-12, Derivative and Hedging ("Topic 815"), Targeted Improvements to Accounting for Hedging Activities. Pursuant to this adoption, effective January 1, 2017, the resultant foreign exchange gain/(loss) upon settlement of cash flow hedges are recorded in the consolidated statements of income along with the underlying hedged item in the same line as either part of “Cost of revenue”, “General and administrative expenses”, “Selling and marketing expenses”, “Depreciation and amortization”, as applicable. Prior to January 1, 2017, the resultant foreign exchange gain/(loss) on settlement of cash flow hedges and changes in the fair value of cash flow hedges deemed ineffective have been recorded in “Foreign exchange gain, net” in the consolidated statements of income. The Company also uses derivatives instruments consisting of foreign currency exchange contracts to economically hedge intercompany balances and other monetary assets or liabilities denominated in currencies other than the functional currency. Changes in the fair value of these derivatives are recognized in the consolidated statements of income and are included in foreign exchange gain/(loss). The Company evaluates hedge effectiveness of cash flow hedges at the time a contract is entered into as well as on an ongoing basis. For hedge relationships that are discontinued because the forecasted transaction is not expected to occur by the end of the originally specified period, any related derivative amounts recorded in equity are reclassified to earnings. (n) Borrowings The Company accounts for convertible notes in accordance with the guidelines established by the ASC 470-20, Debt with Conversion and Other Options. The Company separates the Notes into liability and equity components. The Beneficial Conversion Feature ("BCF") of a convertible note, which is the equity component and recorded as additional paid-in capital, is normally characterized as the convertible portion or feature of certain notes payable that provide a rate of conversion that is below market value or in-the-money when issued. The Company records a BCF related to the issuance of a convertible note when issued. If a convertible note is within the scope of the Cash Conversion Subsections and contains embedded features other than the embedded conversion option, the guidance in ASC 815-15, Derivatives and Hedging - Embedded Derivatives (ASC 815-15), is applied to determine if any of those features must be separately accounted for as a derivative instrument. The estimated fair value of the liability component at issuance is determined using a discounted cash flow technique, which considers debt issuances with similar features of the Company’s convertible notes, excluding the conversion feature. The excess of the gross proceeds received over the estimated fair value of the liability component is allocated to the BCF, which is credited to additional paid-in-capital, with a corresponding offset recognized as a discount to reduce the net carrying value of the convertible notes. The discount is amortized to interest expense over the expected term of the convertible notes using the effective interest method. (o) Employee Benefits Contributions to defined contribution plans are charged to the consolidated statements of income in the period in which serv

Segment & Geographical Informat

Segment & Geographical Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment & Geographical Information	Segment and Geographical Information The Company operates in the BPM industry and is a provider of operations management and analytics services. The Company has eight operating segments which are strategic business units that align its products and services with how it manages its business, approaches its key markets and interacts with its clients. Six of those operating segments provide BPM or “operations management” services, five of which are industry-focused operating segments (Insurance, Healthcare, Travel, Transportation and Logistics, Banking and Financial Services, and Utilities) and one of which is a “capability” operating segment (Finance and Accounting) that provides services to clients in our industry-focused segments as well as clients across other industries. In each of these six operating segments, the Company provides operations management services, which typically involve transfer to the Company of the business operations of a client, after which it administers and manages those operations for its client on an ongoing basis. The remaining two operating segments are Consulting, which provides industry-specific transformational services related to operations management services, and Analytics, which provides services that focus on driving improved business outcomes for clients by generating data-driven insights across all parts of their business. The Company presents information for the following reportable segments: • Insurance • Healthcare • Travel, Transportation and Logistics (“TT&L”) • Finance and Accounting (“F&A”) • Analytics, and • All Other (consisting of the Company's remaining operating segments which are the Banking and Financial Services, Utilities and Consulting operating segments). The chief operating decision maker (“CODM”) generally reviews financial information such as revenues, cost of revenues and gross profit, disaggregated by the operating segments to allocate an overall budget among the operating segments. The Company does not allocate and therefore the CODM does not evaluate other operating expenses, interest expense or income taxes by segment. Many of the Company’s assets are shared by multiple operating segments. The Company manages these assets on a total Company basis, not by operating segment, and therefore asset information and capital expenditures by operating segment are not presented. The July 2018 acquisition of SCIOinspire Holdings Inc. (“SCIO”) is included in the Analytics reportable segment. The December 2017 acquisition of substantially all of the assets, and assumption of certain liabilities related thereto, of Health Integrated, Inc. (“Health Integrated”) is included in the Healthcare reportable segment. Revenues and cost of revenues for each of the years ended December 31, 2018, 2017 and 2016, for each of the reportable segments, are as follows: Year ended December 31, 2018 Insurance Healthcare TT&L F&A All Other Analytics Total Revenues, net $ 258,144 $ 84,391 $ 70,237 $ 97,941 $ 87,109 $ 285,290 $ 883,112 Cost of revenues (1) 174,921 66,768 41,066 59,155 58,341 184,604 584,855 Gross profit (1) $ 83,223 $ 17,623 $ 29,171 $ 38,786 $ 28,768 $ 100,686 $ 298,257 Operating expenses 248,436 Foreign exchange gain, interest expense and other income, net 10,549 Income tax expense 3,397 Loss from equity-method investment 247 Net income $ 56,726 Year ended December 31, 2017 Insurance Healthcare TT&L F&A All Other Analytics Total Revenues, net $ 234,794 $ 77,013 $ 70,951 $ 86,527 $ 83,082 $ 209,943 $ 762,310 Cost of revenues (1)(2)(3) 159,433 49,412 41,337 51,362 56,638 136,960 495,142 Gross profit (1)(2)(3) $ 75,361 $ 27,601 $ 29,614 $ 35,165 $ 26,444 $ 72,983 $ 267,168 Operating expenses (2)(3) 194,443 Foreign exchange gain, interest expense and other income, net (2)(3) 12,309 Income tax expense 36,146 Net income $ 48,888 Year ended December 31, 2016 Insurance Healthcare TT&L F&A All Other Analytics Total Revenues, net $ 206,327 $ 68,656 $ 69,366 $ 79,416 $ 96,489 $ 165,734 $ 685,988 Cost of revenues (1)(3) 146,151 44,060 41,923 48,258 61,019 106,307 447,718 Gross profit (1)(3) $ 60,176 $ 24,596 $ 27,443 $ 31,158 $ 35,470 $ 59,427 $ 238,270 Operating expenses (3) 173,775 Foreign exchange gain, interest expense and other income, net (3) 19,389 Income tax expense 22,151 Net income $ 61,733 (1) Exclusive of depreciation and amortization. (2) The Company early adopted ASU No. 2017-12, Derivative and Hedging ("Topic 815"), Targeted Improvements to Accounting for Hedging Activities . Pursuant to this adoption, effective January 1, 2017, the resultant foreign exchange gain/(loss) upon settlement of cash flow hedges are recorded along with the underlying hedged item in the same line as either part of “Cost of revenues”, “General and administrative expenses”, “Selling and marketing expenses”, and "Depreciation and amortization”, as applicable. Refer to Note 18 to the consolidated financial statements for details. (3) Effective January 1, 2018, the Company adopted ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost . Pursuant to this, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the 2017 and 2016 consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The interest cost, expected return on plan assets and amortization of actuarial (gain)/loss, have been reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. Refer to Note 21 and Note 27 to the consolidated financial statements for details. Revenues, net of the Company by service type, were as follows: Year ended December 31, 2018 2017 2016 BPM and related services (1) $ 597,822 $ 552,367 $ 520,254 Analytics services 285,290 209,943 165,734 Total $ 883,112 $ 762,310 $ 685,988 (1) BPM and related services include revenues of the Company's five industry-focused operating segments, one capability operating segment and the consulting operating segment, which provides services related to operations management services. Refer to segment disclosure above. The Company attributes the revenues to regions based upon the location of its customers. Year ended December 31, 2018 2017 2016 Revenues, net United States $ 732,589 $ 626,336 $ 554,945 Non-United States United Kingdom 114,515 108,640 109,905 Rest of World 36,008 27,334 21,138 Total Non-United States $ 150,523 $ 135,974 $ 131,043 $ 883,112 $ 762,310 $ 685,988 Property and equipment, net by geographic area, were as follows: As of December 31, 2018 December 31, 2017 Property and equipment, net India $ 36,152 $ 39,143 United States 28,254 16,371 Philippines 5,985 8,217 Rest of World 3,119 3,026 $ 73,510 $ 66,757

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) Summarized quarterly results for the years ended December 31, 2018 and 2017 are as follows: Three months ended 2018 Year ended March 31 June 30 September 30 December 31 December 31, 2018 Revenues, net $ 206,973 $ 210,112 $ 231,124 $ 234,903 $ 883,112 Gross profit (1) $ 68,872 $ 70,463 $ 78,967 $ 79,955 $ 298,257 Net income $ 23,158 $ 14,462 $ 15,249 $ 3,857 $ 56,726 Earnings per share: Basic $ 0.67 $ 0.42 $ 0.44 $ 0.11 $ 1.65 Diluted $ 0.66 $ 0.41 $ 0.43 $ 0.11 $ 1.62 Weighted-average number of shares used in computing earnings per share: Basic 34,446,265 34,511,777 34,458,520 34,388,025 34,451,008 Diluted 35,302,926 35,142,388 35,207,991 34,921,388 35,030,984 Stock compensation expense $ 5,074 $ 6,893 $ 5,344 $ 6,590 $ 23,901 Amortization of intangibles $ 3,947 $ 3,761 $ 6,718 $ 5,951 $ 20,377 Three months ended 2017 Year ended March 31 June 30 September 30 December 31 December 31, 2017 Revenues, net $ 183,033 $ 189,057 $ 192,345 $ 197,875 $ 762,310 Gross profit (1)(2)(3) $ 63,961 $ 65,323 $ 69,268 $ 68,616 $ 267,168 Net income/(loss) $ 16,788 $ 20,378 $ 21,077 $ (9,355 ) $ 48,888 Earnings/(loss) per share: Basic (4) $ 0.50 $ 0.60 $ 0.62 $ (0.27 ) $ 1.44 Diluted (4) $ 0.48 $ 0.58 $ 0.60 $ (0.27 ) $ 1.39 Weighted-average number of shares used in computing earnings per share: Basic (4) 33,845,560 33,819,320 33,838,374 34,086,711 33,897,916 Diluted (4) 35,108,882 34,993,226 35,043,987 34,086,711 35,110,210 Stock compensation expense $ 5,956 $ 5,107 $ 5,708 $ 6,270 $ 23,041 Amortization of intangibles $ 3,498 $ 3,507 $ 3,487 $ 3,483 $ 13,975 (1) Exclusive of depreciation and amortization. (2) During the quarter ended December 31, 2017, the Company early adopted ASU No. 2017-12, Derivative and Hedging ("Topic 815"), Targeted Improvements to Accounting for Hedging Activities . Pursuant to this adoption effective January 1, 2017, the Company recorded settlement gain/(loss) on cash flow hedges in cost of revenues and operating expenses, as applicable, in the consolidated statements of income for each of the quarters of 2017. Refer Note 18 for further details. (3) Effective January 1, 2018, the Company adopted ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost . Pursuant to this, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the 2017 and 2016 consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The interest cost, expected return on plan assets and amortization of actuarial gains/loss, have been reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. (4) Total of quarterly basic and diluted earnings per share and weighted average number of shares used in computing earnings per share will not be equal to year end basic and diluted earnings per share and weighted average number of shares used in computing earnings per share, respectively. For the quarter ended December 31, 2017, nil weighted average common shares were considered anti-dilutive and not included in computing diluted earnings per share.

Revenues, net

Revenues, net	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenues, net	Revenues, net Adoption of ASU No. 2014-09 Topic 606, “Revenue from Contracts with Customers” On January 1, 2018, the Company adopted Topic 606 using the modified retrospective method and applied its guidance to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts are not adjusted and continue to be reported in accordance with our historical accounting under Topic 605. The Company recorded a net addition to opening retained earnings of $454 as of January 1, 2018 due to the cumulative impact of adopting Topic 606, primarily due to contract acquisition costs. The adoption of Topic 606 did not have a significant impact on the measurement or recognition of revenues during year ended December 31, 2018. Refer to Note 3 to the consolidated financial statements for revenues disaggregated by reportable segments and geography. Contract balances The following table provides information about accounts receivable, contract assets and contract liabilities from contracts with customers: As of December 31, 2018 December 31, 2017 Accounts receivable, net $ 164,752 $ 135,705 Contract assets $ 5,445 $ 2,643 Contract liabilities Deferred revenue (advance payments portion) $ 6,345 $ 9,311 Consideration received from customer for transitions activities $ 1,669 $ 1,601 Accounts receivable includes $63,952 and $49,125 as of December 31, 2018 and December 31, 2017, respectively, representing amounts not billed to customers. The Company has accrued the unbilled receivables for work performed in accordance with the terms of contracts with customers and considers no significant performance risk associated with its unbilled receivables. Contract assets represents upfront payments made to customers. Contract liabilities represents that portion of deferred revenue for which payments have been received in advance from customers including revenues attributable to certain process transition activities for which costs have been capitalized by the Company as contract fulfillment costs. The contract liabilities are included within deferred revenues in the consolidated balance sheet and are recognized as revenue as (or when) the performance obligation is fulfilled under the contract. Revenue recognized from the carrying value of contract liabilities as of December 31, 2017 during the year ended December 31, 2018 was $9,147 . Contract acquisition costs The Company had contract acquisition costs of $713 as of December 31, 2018. As of January 1, 2018, the Company capitalized $454 as contract acquisition costs related to contracts that were not completed. Further, the Company capitalized an additional $567 during the year ended December 31, 2018, and amortized $308 during the year ended December 31, 2018. There was no impairment loss in relation to costs capitalized. The capitalized costs are being amortized on a straight-line basis over the life of contract. Contract fulfillment costs The Company had deferred contract fulfillment costs relating to transition activities of $4,051 and $2,769 as of December 31, 2018 and December 31, 2017, respectively. The Company capitalized an additional $2,216 during the year ended December 31, 2018, and amortized $934 during the year ended December 31, 2018. There was no impairment loss in relation to costs capitalized. The capitalized costs are being amortized on a straight line basis over the life of contract. Consideration received from customers, if any, relating to such transition activities are classified under Contract Liabilities and are recognized ratably over the period in which the related performance obligations are fulfilled.

Other Income, net

Other Income, net	12 Months Ended
	Dec. 31, 2018
Other Nonoperating Income (Expense) [Abstract]
Other Income, net	Other Income, net Other Income, net consists of the following: Year ended December 31, 2018 2017 2016 Interest and dividend income $ 1,873 $ 1,625 $ 1,673 Gain on sale and mark-to-market of mutual funds 9,970 8,766 8,087 Change in fair value of earn-out consideration — — 4,060 Others, net 1,146 968 1,315 Other income, net $ 12,989 $ 11,359 $ 15,135 Effective January 1, 2018, the Company adopted ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost . Pursuant to this, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the 2017 and 2016 consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The interest cost, expected return on plan assets and amortization of actuarial (gain)/loss, have been reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. Refer to Note 21 and Note 27 to the consolidated financial statements for details.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per share is computed by dividing net income to common stockholders by the weighted average number of common shares outstanding during each period. Diluted earnings per share is computed using the weighted average number of common shares plus the potentially dilutive effect of common stock equivalents (outstanding stock options, restricted stock and restricted stock units) issued and outstanding at the reporting date, using the treasury stock method. Stock options, restricted stock and restricted stock units that are anti-dilutive are excluded from the computation of weighted average shares outstanding. The following table sets forth the computation of basic and diluted earnings per share: Year ended December 31, 2018 2017 2016 Numerator: Net income $ 56,726 $ 48,888 $ 61,733 Denominators: Basic weighted average common shares outstanding 34,451,008 33,897,916 33,566,367 Dilutive effect of share based awards 579,976 1,212,294 996,952 Diluted weighted average common shares outstanding 35,030,984 35,110,210 34,563,319 Earnings per share attributable to ExlService Holdings, Inc. stockholders: Basic $ 1.65 $ 1.44 $ 1.84 Diluted $ 1.62 $ 1.39 $ 1.79 Weighted average potentially dilutive shares considered anti-dilutive and not included in computing diluted earnings per share 121,344 151,961 92,538

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash (Notes)	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash For the purpose of statements of cash flows, cash, cash equivalents and restricted cash comprise of the following: As of December 31, 2018 December 31, 2017 December 31, 2016 Cash and cash equivalents $ 95,881 $ 86,795 $ 213,155 Restricted cash (current) 5,608 3,674 3,846 Restricted cash (non-current) 2,642 3,808 3,393 $ 104,131 $ 94,277 $ 220,394 Effective January 1, 2018, the Company adopted ASU 2016-18, Statements of Cash Flows (Topic 230), Restricted Cash . Accordingly, for 2017 and 2016, restricted cash and restricted cash equivalents is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown in the consolidated statements of cash flows. Refer to Note 27 to the consolidated financial statements.

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net Property and equipment, net consist of the following: As of Estimated useful lives (Years) December 31, 2018 December 31, 2017 Owned Assets: Network equipment and computers 3-5 $ 85,921 $ 77,587 Software 3-5 69,752 59,325 Leasehold improvements 3-8 39,533 38,857 Office furniture and equipment 3-8 20,097 19,667 Motor vehicles 2-5 635 638 Buildings 30 1,140 1,245 Land — 746 815 Capital work in progress — 11,026 9,184 228,850 207,318 Less: Accumulated depreciation and amortization (155,798 ) (141,059 ) $ 73,052 $ 66,259 Assets under capital leases: Leasehold improvements $ 778 $ 941 Office furniture and equipment 53 167 Motor vehicles 628 710 1,459 1,818 Less: Accumulated depreciation and amortization (1,001 ) (1,320 ) $ 458 $ 498 Property and equipment, net $ 73,510 $ 66,757 Capital work in progress represents advances paid towards acquisition of property and equipment and cost incurred to develop software not yet ready to be placed in service. The depreciation and amortization expense excluding amortization of acquisition-related intangibles recognized in the consolidated statements of income was as follows: Year ended December 31, 2018 2017 2016 Depreciation and amortization expense $ 28,189 $ 24,574 $ 22,707 Effective January 1, 2017, the depreciation and amortization expenses set forth above includes the effect of foreign exchange gain/(loss) upon settlement of cash flow hedges, amounting to $153 and $435 for the years ended December 31, 2018 and 2017, respectively (refer Note 18 to the consolidated financial statements for further details). Internally developed software costs, included under Software, was as follows: As of December 31, 2018 December 31, 2017 Cost $ 8,783 $ 2,571 Less : Accumulated amortization (2,393 ) (976 ) $ 6,390 $ 1,595 During the year ended December 31, 2018, there were no changes in estimated useful lives of property and equipment. The amortization expense on internally developed software recognized in the consolidated statements of income was as follows: Year ended December 31, 2018 2017 2016 Amortization expense $ 1,417 $ 640 $ 336

Business Combinations, Goodwill

Business Combinations, Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2018
Business Combinations, Goodwill and Intangible Assets Disclosure [Abstract]
Business Combinations, Goodwill and Intangible Assets	Business Combinations, Goodwill and Intangible Assets SCIOinspire Holdings Inc. On July 1, 2018, the Company, through its wholly owned subsidiary ExlService.com, LLC (“Buyer”) and Buyer’s wholly owned subsidiary, ExlService Cayman Merger Sub, completed the acquisition of SCIO pursuant to an Agreement of Merger dated April 28, 2018 (the "Merger Agreement"). ExlService Cayman Merger Sub, merged with and into SCIO, with SCIO surviving the merger as a wholly-owned subsidiary of the Buyer. SCIO is a health analytics solution and services company serving healthcare organizations including providers, health plans, pharmacy benefit managers, employers, health services and global life sciences companies. The acquisition is expected to significantly strengthen the Company’s capability in the high growth cost optimization and care optimization markets. The acquisition of SCIO is included in the Analytics reportable segment. The aggregate purchase consideration was $245,044 , including cash and cash equivalents acquired and post-closing adjustments. The aggregate base purchase consideration payable at closing of the merger was $236,500 based on completion of diligence, which was adjusted based on, among other things, SCIO’s cash, debt, working capital position and other adjustments as of the Closing as set forth in the Merger Agreement. To finance the acquisition at Closing, the Company utilized its revolving credit facility in the amount of $233,000 , issued 69,459 shares of restricted common stock of the Company in the amount of $4,080 and paid the balance with available cash on hand. Pursuant to the Company’s business combinations accounting policy, the total purchase consideration for SCIO was allocated to identifiable net tangible and intangible assets based upon their preliminary fair values. The excess of the estimated purchase consideration over fair value of identifiable net tangible and intangible assets was recorded as goodwill. In order to allocate the consideration transferred for SCIO, the fair values of all identifiable assets and liabilities must be established. For accounting and financial reporting purposes, fair value is defined under ASC No. 820, Fair Value Measurement and Disclosure , as the price that would be received upon sale of an asset or the amount paid to transfer a liability in an orderly transaction between market participants at the measurement date. Market participants are assumed to be buyers and sellers in the principal (most advantageous) market for the asset or liability. Additionally, fair value measurements for an asset assume the highest and best use of that asset by market participants. Use of different estimates and judgments could yield different results. The Company’s preliminary purchase price allocation to net tangible and intangible assets of SCIO is as follows: Assets: Cash and cash equivalents $ 9,842 Restricted cash 2,790 Accounts receivable 19,924 Other current assets 2,076 Property and equipment 1,824 Other assets 1,751 Intangible assets Customer relationships 47,800 Developed technology 21,400 Trade names and trademarks 3,700 111,107 Liabilities: Current liabilities (12,482 ) Deferred tax liabilities, net (17,132 ) Other non-current liabilities (200 ) (29,814 ) Net assets acquired $ 81,293 Goodwill 163,751 Total purchase consideration $ 245,044 The fair value of assets acquired and liabilities assumed from the acquisition of SCIO is based on a preliminary valuation and, as such, the Company's estimates and assumptions are subject to change within the measurement period. The primary areas of the purchase price that are not yet finalized are related to direct and indirect taxes. The fair values of the trade names and trademarks intangible assets were determined by using an “income approach”, specifically the relief-from-royalty approach. The basic principle of the relief-from-royalty method is that without ownership of the subject intangible asset, the user of that intangible asset would have to make a stream of payments to the owner of the asset in return for the rights to use that asset. By acquiring the intangible asset, the user avoids these payments. Therefore, a portion of SCIO’s earnings, equal to the after-tax royalty that would have been paid for the use of the asset, can be attributed to the firm’s ownership. The trade names and trademarks are being amortized on a straight-line basis (which approximates the economic pattern of benefits) over the estimated economic life of 3 years . The fair values of the developed technology intangible assets were also determined by the relief-from-royalty approach. Similarly, this approach is based on the assumption that in lieu of ownership, a firm would be willing to pay a royalty in order to exploit the related benefits of the technology. Therefore, a portion of SCIO’s earnings, equal to the after-tax royalty that would have been paid for the use of the technology, can be attributed to the firm’s ownership of the technology. The technology assets are being amortized on a straight-line basis (which approximates the economic pattern of benefits) over the estimated economic life of 5 years . The fair values of the customer relationships were determined by using an “income approach”, specifically the Multi-Period Excess Earnings Method ("MPEEM"). The MPEEM is a specific application of the discounted cash flow method. The principle behind the MPEEM is that the value of an intangible asset is equal to the present value of the incremental after-tax cash flows attributable only to the subject intangible asset after deducting Contributory Asset Charges ("CAC"). The principle behind a CAC is that an intangible asset ‘rents’ or ‘leases’ from a hypothetical third party all the assets it requires to produce the cash flows resulting from its development, that each project rents only those assets it needs (including elements of goodwill) and not the ones that it does not need, and that each project pays the owner of the assets a fair return on (and of, when appropriate) the value of the rented assets. The customer relationship assets are being amortized on a straight-line basis (which approximates the economic pattern of benefits) over the estimated economic life of 10 years . The goodwill recognized is attributable primarily to expected synergies from continuing operations of SCIO and the Company. The amount of goodwill recognized from SCIO's acquisition is not deductible for tax purposes. The goodwill has been assigned to our Analytics reportable segment based upon the Company’s assessment of nature of services rendered by SCIO. Actual and Unaudited Pro Forma Financial Information The Company completed the acquisition of SCIO on July 1, 2018 and accordingly SCIO’s operations for the period from July 1, 2018 to December 31, 2018 are included in the Company’s consolidated statements of income. SCIO contributed revenues of $40,038 for the period from the completion of acquisition through December 31, 2018. The Company does not allocate other operating expenses, interest expense or income taxes by legal entity, and therefore the Company has not presented earnings of SCIO for the period from the completion of acquisition through December 31, 2018. The following unaudited pro forma results of operations have been prepared using the acquisition method of accounting to give effect to the SCIO acquisition as though it occurred on January 1, 2017. The pro forma amounts reflect certain adjustments, such as amortization of intangible assets acquired, interest expense related to borrowings not assumed by the Company and stock based compensation expense. The unaudited pro forma financial information is presented for illustrative purposes only, is based on a preliminary purchase price allocation, and is not necessarily indicative of the results of operations that would have actually been reported had the acquisition occurred on January 1, 2017, nor is it necessarily indicative of the future results of operations of the combined company. Unaudited Year ended December 31, 2018 2017 Revenues, net $ 924,172 $ 834,158 Net income $ 55,756 $ 45,827 Earnings per share: Basic $ 1.62 $ 1.35 Diluted $ 1.59 $ 1.30 Health Integrated, Inc. On December 22, 2017 , a wholly owned subsidiary of the Company entered into an Asset Purchase Agreement to acquire substantially all the assets and assumed certain liabilities of Health Integrated, Inc. (“Health Integrated”), a company based in Tampa, Florida. The aggregate purchase consideration of $22,811 was paid in cash including post-closing adjustments. The purchase agreement allows sellers the ability to earn up to $5,000 as earn-out, based on the achievement of certain performance goals by the acquired Health Integrated business during the 2018 calendar year, which were not achieved. The earn-out was fair valued at $920 as of December 31, 2017. As of December 31, 2018, fair value of earn-out was $ nil . A portion of the purchase consideration otherwise payable was placed into escrow as security for the post-closing working capital adjustments and the indemnification obligations under the Asset Purchase Agreement. Health Integrated provides dedicated care management services on behalf of health plans. Its services include case management, utilization management, disease management, special needs programs, and multichronic care management. Health Integrated serves lives in the Medicaid, Medicare, and dual eligible populations. It is known for its capabilities in improving member health status through behavioral change. Accordingly, the Company paid a premium for the acquisition, which is reflected in the goodwill recognized from the purchase price allocation. The acquisition of Health Integrated is included in the Healthcare reportable segment. The Company finalized its purchase price allocation for the acquisition based on their fair values as set forth below: Amount Tangible Assets $ 5,475 Liabilities (5,733 ) Identifiable Intangible Assets: Customer relationships 6,760 Developed technology 1,510 Trade names and trademarks 570 Goodwill 14,229 Total purchase price $ 22,811 The amount of goodwill recognized from the Health Integrated acquisition is deductible for tax purposes. The customer relationships from the Health Integrated acquisition were being amortized prior to impairment testing over the weighted average useful life of 7.0 years and developed technology and trademarks over the useful life of 1.0 year and 2.0 years , respectively. The goodwill, customer relationship and trademarks from the Health Integrated acquisition were impaired during the fourth quarter of 2018. Refer to the Goodwill and Intangible Assets details below. The Company also issued 4,444 shares of restricted stock units with an aggregate fair value of $275 to certain key employees of Health Integrated, each of whom accepted employment positions with the Company upon consummation of the combination. The restricted stock units vest proportionally over four years and the fair value of these grants will be recognized as compensation expense on a straight-line basis over the vesting term. Actual and Unaudited Pro Forma Financial Information The following unaudited pro forma results of operations have been prepared using the acquisition method of accounting to give effect to the Health Integrated acquisition as though it occurred on January 1, 2016. The Company completed its acquisition of Health Integrated on December 22, 2017 and accordingly Health Integrated’s operations for the period from December 22, 2017 to December 31, 2017 are included in the Company’s consolidated statement of income. The pro forma amounts reflect certain adjustments, such as depreciation and amortization on assets acquired, interest expense related to liabilities not assumed by the Company and facility costs for certain facilities not acquired. The unaudited pro forma financial information is presented for illustrative purposes only, is based on purchase price allocation, and is not necessarily indicative of the results of operations that would have actually been reported had the acquisitions occurred on January 1, 2016, nor is it necessarily indicative of the future results of operations of the combined company. Unaudited Year ended December 31, 2017 2016 Revenues $ 801,101 $ 729,938 Net income $ 46,998 $ 58,232 Earnings per share: Basic $ 1.39 $ 1.73 Diluted $ 1.34 $ 1.68 Acquisition-related costs Acquisition-related costs are being expensed as incurred and are included in general and administrative expenses in the consolidated statements of income. The Company recognized acquisition-related costs of $1,315 and $826 during the years ended December 31, 2018 and 2017, respectively, which were incurred by the Company to effect its business combinations for the SCIO and Health Integrated acquisitions. Goodwill The following table sets forth details of changes in goodwill by reportable segment of the Company: Insurance Healthcare TT&L F&A All Other Analytics Total Balance as at January 1, 2017 $ 38,110 $ 19,276 $ 12,983 $ 47,537 $ 5,326 $ 63,538 $ 186,770 Acquisitions — 15,957 — — — — 15,957 Currency translation adjustments 223 — 696 835 — — 1,754 Balance as at December 31, 2017 $ 38,333 $ 35,233 $ 13,679 $ 48,372 $ 5,326 $ 63,538 $ 204,481 Acquisitions — — — — — 163,751 163,751 Measurement period adjustments* — (1,728 ) — — — — (1,728 ) Currency translation adjustments (130 ) — (982 ) (1,179 ) — — (2,291 ) Impairment charges — (14,229 ) — — — — (14,229 ) Balance as at December 31, 2018 $ 38,203 $ 19,276 $ 12,697 $ 47,193 $ 5,326 $ 227,289 $ 349,984 * Subsequent to the date of acquisition and upon receipt of additional information, adjustments of $1,728 have been made to the Health Integrated amounts of net tangible assets acquired and the earn-out with the corresponding offset to goodwill. These adjustments are within the measurement period and would be accounted for prospectively. These adjustments did not have a significant impact on the Company’s consolidated statements of income, balance sheets or cash flows. The Company elected to adopt the simplified goodwill impairment testing method under ASU No. 2017-04, based on which its annual goodwill impairment quantitative assessments, carried out in the fourth quarter of 2018. During the fourth quarter of 2018, the Company performed its annual impairment test of goodwill for all its reporting units. Based on the results, the fair values of each of the Company’s reporting units exceeded their carrying values except for the Health Integrated reporting unit, within the Healthcare operating segment. The primary factors contributing to a reduction in the fair value of the Health Integrated reporting unit were: (i) revenues and profitability in 2018 were significantly lower than the Company’s budget; and (ii) significant changes to the Company's estimated future cash flows and long-term growth assumptions for the Health Integrated reporting unit driven by loss of customer contracts, cost pressures and the Company’s most recent views of the long-term outlook for the Health Integrated business. As a result of this analysis, the Company recognized a goodwill impairment charge of $14,229 during the fourth quarter to write down the carrying value of Health Integrated’s goodwill to its fair value of $ nil as of December 31, 2018. This impairment loss was recorded in the consolidated statements of income under "impairment charges". As of December 31, 2018, the Company believes no other goodwill impairment exists, apart from the impairment charges discussed above, and that the remaining goodwill is recoverable for all of its reporting units; however, there can be no assurances that additional goodwill will not be impaired in future periods. Estimating the fair value of reporting units requires the use of estimates and significant judgments that are based on a number of factors including actual operating results. It is reasonably possible that the judgments and estimates described above could change in future periods. Intangible Assets Information regarding the Company’s intangible assets is set forth below: As of December 31, 2018 Gross Carrying Amount Accumulated Amortization Accumulated Impairment Net Carrying Amount Finite-lived intangible assets: Customer relationships $ 129,790 $ (56,367 ) $ (5,549 ) $ 67,874 Leasehold benefits 2,644 (2,567 ) — 77 Developed technology 37,154 (14,653 ) — 22,501 Non-compete agreements 2,045 (1,937 ) — 108 Trade names and trademarks 9,639 (5,326 ) (278 ) 4,035 $ 181,272 $ (80,850 ) $ (5,827 ) $ 94,595 Indefinite-lived intangible assets: Trade names and trademarks $ 900 $ — $ — $ 900 Total intangible assets $ 182,172 $ (80,850 ) $ (5,827 ) $ 95,495 As of December 31, 2017 Gross Carrying Amount Accumulated Amortization Accumulated Impairment Net Carrying Amount Finite-lived intangible assets: Customer relationships $ 82,165 $ (43,667 ) $ — $ 38,498 Leasehold benefits 2,888 (2,596 ) — 292 Developed technology 15,835 (8,749 ) — 7,086 Non-compete agreements 2,045 (1,780 ) — 265 Trade names and trademarks 5,951 (4,034 ) — 1,917 $ 108,884 $ (60,826 ) $ — $ 48,058 Indefinite-lived intangible assets: Trade names and trademarks $ 900 $ — $ — $ 900 Total intangible assets $ 109,784 $ (60,826 ) $ — $ 48,958 The amortization expense for the year is as follows: Year ended December 31, 2018 2017 2016 Amortization expense $ 20,377 $ 13,975 $ 11,873 During the fourth quarter of 2018, the Company recognized impairment charges of $5,549 and $278 related to its customer relationships and trademarks intangible assets, respectively, in the Health Integrated reporting unit, within the Healthcare operating segment. The Company tested these intangible assets for recoverability due to indicators warranting the impairment test such as: (i) revenues and profitability in 2018 were significantly lower than the Company’s budget, and (ii) significant changes to the Company's estimated future cash flows and long -term growth assumptions for the Health Integrated reporting unit driven by loss of customer contracts, cost pressures and the Company’s most recent views of the long-term outlook for the Health Integrated business. Based on the results of its testing, the Company determined that the carrying value of the intangible assets was not recoverable, and an impairment charge was recorded to the extent that carrying value exceeded estimated fair value. This impairment charge was recorded in the consolidated statements of income under "impairment charges". Subsequent to the impairment test, Health Integrated reporting unit’s customer relationships and trademarks intangibles assets were reduced to $ nil as of December 31, 2018. The remaining weighted average life of intangible assets is as follows: (in years) Customer relationships 7.93 Leasehold benefits 0.41 Developed technology 4.34 Non-compete agreements 0.72 Trade names and trademarks (Finite lived) 3.11 Estimated future amortization expense related to intangible assets as of December 31, 2018 is as follows: 2019 $ 21,543 2020 14,442 2021 12,743 2022 11,331 2023 9,042 2024 and thereafter 25,494 Total $ 94,595

Investment in Equity Affiliate

Investment in Equity Affiliate	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Investment in Equity Affiliate	Investment in Equity Affiliate On December 12, 2017 , the Company acquired preferred stock in Corridor Platforms Inc. (“Corridor”), a big data credit risk management platform for $3,000 . The Company has determined that based on its ownership interest and other rights, Corridor is an equity method affiliate, whereby the Company holds 26% ownership interest. The Company has the right and option to acquire additional preferred stock from Corridor as per the terms of the agreement. The Company's proportionate share of net loss for the year ended December 31, 2018 was $247 and for the period from December 12, 2017 to December 31, 2017 was $ nil .

Other Current Assets

Other Current Assets	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Current Assets	Other Current Assets Other current assets consist of the following: As of December 31, 2018 December 31, 2017 Derivative instruments $ 4,059 $ 10,938 Advances to suppliers 2,910 2,451 Receivables from statutory authorities 14,145 7,598 Contract assets 1,201 401 Deferred contract fulfillment costs 1,236 474 Others 4,689 7,720 Other current assets $ 28,240 $ 29,582

Other Assets

Other Assets	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Other Assets Other assets consist of the following: As of December 31, 2018 December 31, 2017 Lease deposits $ 8,891 $ 8,776 Derivative instruments 1,971 7,361 Deposits with statutory authorities 6,259 6,492 Term deposits 315 6,909 Contract assets 4,244 2,242 Deferred contract fulfillment costs 2,815 2,295 Others 6,520 2,294 Other assets $ 31,015 $ 36,369

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2018
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following: As of December 31, 2018 December 31, 2017 Accrued expenses $ 44,711 $ 43,235 Derivative instruments 3,204 555 Client liabilities 6,933 8,982 Other current liabilities 9,321 8,594 Accrued expenses and other current liabilities $ 64,169 $ 61,366

Other Non-current liabilities

Other Non-current liabilities	12 Months Ended
	Dec. 31, 2018
Liabilities, Noncurrent [Abstract]
Other Non-current liabilities	Other Non-current Liabilities Other non-current liabilities consist of the following: As of December 31, 2018 December 31, 2017 Derivative instruments $ 3,075 $ 322 Unrecognized tax benefits 804 892 Deferred rent 7,834 8,176 Retirement benefits 3,616 3,377 Deferred transition revenue 945 1,034 Others 247 2,401 Other non-current liabilities $ 16,521 $ 16,202

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Accumulated other comprehensive loss ("AOCI") consists of amortization of actuarial gain/(loss) on retirement benefits and changes in the cumulative foreign currency translation adjustments. In addition, the Company enters into foreign currency exchange contracts, which are designated as cash flow hedges in accordance with ASC Topic 815. Changes in the fair values of forward contracts are recognized in accumulated other comprehensive loss on the Company's consolidated balance sheet until the settlement of those contracts. The balances as of December 31, 2018 and 2017 are as follows: As of December 31, 2018 December 31, 2017 Cumulative foreign currency translation gain/(loss) $ (84,105 ) $ (58,405 ) Unrealized gain/(loss) on cash flow hedges, net of taxes of $115 and $4,918, respectively (333 ) 11,932 Retirement benefits, net of taxes of ($53) and ($74), respectively 971 763 Accumulated other comprehensive gain/(loss) $ (83,467 ) $ (45,710 )

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements ASC Topic 820, “Fair Value Measurements and Disclosures ” ("ASC 820") defines fair value as the price that would be received upon sale of an asset or paid upon transfer of a liability in an orderly transaction between market participants at the measurement date and in the principal or most advantageous market for that asset or liability. The fair value should be calculated based on assumptions that market participants would use in pricing the asset or liability, not on assumptions specific to the entity. In addition, the fair value of liabilities should include consideration of non-performance risk, including the Company’s own credit risk. ASC 820 establishes a three-level hierarchy of fair value measurements based on whether the inputs to those measurements are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s market assumptions. The fair-value hierarchy requires the use of observable market data when available and consists of the following levels: • Level 1—Quoted prices for identical instruments in active markets; • Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets; and • Level 3—Valuations derived from valuation techniques in which one or more significant inputs are unobservable. Assets and Liabilities Measured at Fair Value The following table sets forth the Company’s assets and liabilities that were accounted for at fair value as of December 31, 2018 and 2017 . As of December 31, 2018 Level 1 Level 2 Level 3 Total Assets Mutual funds* $ 142,408 $ — $ — $ 142,408 Derivative financial instruments — 6,030 — 6,030 Total $ 142,408 $ 6,030 $ — $ 148,438 Liabilities Derivative financial instruments $ — $ 6,279 $ — $ 6,279 Total $ — $ 6,279 $ — $ 6,279 As of December 31, 2017 Level 1 Level 2 Level 3 Total Assets Mutual funds* $ 162,906 $ — $ — $ 162,906 Derivative financial instruments — 18,298 — 18,298 Total $ 162,906 $ 18,298 $ — $ 181,204 Liabilities Derivative financial instruments $ — $ 877 $ — $ 877 Fair value of earn-out consideration — — 920 920 Total $ — $ 877 $ 920 $ 1,797 * Represents short-term investments carried on fair value option under ASC 825 "Financial Instruments" as of December 31, 2018 and December 31, 2017. Derivative Financial Instruments: The Company’s derivative financial instruments consist of foreign currency forward exchange contracts. Fair values for derivative financial instruments are based on independent sources including highly rated financial institutions and are classified as Level 2. Refer to Note 18 to the consolidated financial statements for further details. Fair value of earn-out consideration: The fair value measurement of earn-out consideration is determined using Level 3 inputs. The Company’s earn-out consideration represents a component of the total purchase consideration for its acquisition of Health Integrated. The measurement was calculated using unobservable inputs based on the Company’s own assessment of achievement of certain performance goals by Health Integrated during the 2018 calendar year which were not achieved. The earn-out was fair valued at $920 as of December 31, 2017. As of December 31, 2018, fair value of earn-out is $ nil . Financial instruments not carried at fair value : The Company’s other financial instruments not carried at fair value consist primarily of accounts receivable, accounts payable and accrued expenses for which fair values approximate their carrying amounts due to their short-term nature. Convertible Notes: The total estimated fair value of the Notes as of December 31, 2018 was $130,510 . The fair value was determined based on the market yields for similar Notes as of the December 31, 2018. The Company considers the fair value of the Notes to be a Level 2 measurement due to the limited inputs available for its fair valuation.

Derivatives and Hedge Accountin

Derivatives and Hedge Accounting	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedge Accounting	Derivatives and Hedge Accounting The Company uses derivative instruments and hedging transactions to mitigate exposure to foreign currency fluctuation risks associated with forecasted transactions denominated in certain foreign currencies and to minimize earnings and cash flow volatility associated with changes in foreign currency exchange rates. The Company’s derivative financial instruments are largely forward foreign exchange contracts that are designated as effective hedges and that qualify as cash flow hedges under ASC 815. The Company had outstanding cash flow hedges totaling $362,435 (including $6,900 of range forward contracts) as of December 31, 2018 and $300,757 as of December 31, 2017 . Changes in the fair value of these cash flow hedges are recorded as a component of accumulated other comprehensive income / (loss), net of tax, until the hedged transactions occurs. The Company early adopted ASU No. 2017-12, Derivative and Hedging (Topic 815), Targeted Improvements to Accounting for Hedging Activities . Pursuant to this adoption, effective January 1, 2017, the resultant foreign exchange gain/(loss) on settlement of cash flow hedges are recorded along with the underlying hedged item in the same line of consolidated statements of income as either a part of “Cost of revenues”, “General and administrative expenses”, “Selling and marketing expenses” or “Depreciation and amortization”, as applicable. Prior to January 1, 2017, the resultant foreign exchange gain/(loss) on settlement of cash flow hedges and changes in the fair value of cash flow hedges deemed ineffective were recorded in “Foreign exchange gain, net” in the consolidated statements of income. The Company also enters into foreign currency forward contracts to economically hedge its intercompany balances and other monetary assets and liabilities denominated in currencies other than functional currencies. These derivatives do not qualify as fair value hedges under ASC 815. Changes in the fair value of these derivatives are recognized in the consolidated statements of income and are included in foreign exchange gain/(loss). The Company’s primary exchange rate exposure is with the Indian Rupee, the U.K. pound sterling and the Philippine peso. The Company also has exposure to Colombian pesos, Czech Koruna, the Euro, South African ZAR and other local currencies in which it operates. Outstanding foreign currency forward contracts amounted to $125,503 , GBP 15,616 and EUR 512 as of December 31, 2018 and amounted to $97,949 , GBP 17,947 and EUR 848 as of December 31, 2017 . The Company estimates that approximately $885 of net derivative gains, excluding tax effects, included in AOCI, representing changes in the fair value of cash flow hedges, could be reclassified into earnings within the next twelve months based on exchange rates prevailing as of December 31, 2018 . At December 31, 2018 , the maximum outstanding term of the cash flow hedges was 45 months. The Company evaluates hedge effectiveness at the time a contract is entered into as well as on an ongoing basis. For hedging positions that are discontinued because the forecasted transaction is not expected to occur by the end of the originally specified period, any related amounts recorded in equity are reclassified to earnings. The following tables set forth the fair value of the foreign currency exchange contracts and their location on the consolidated balance sheets: Derivatives designated as hedging instruments : As of Foreign currency exchange contracts December 31, 2018 December 31, 2017 Other current assets $ 4,022 $ 10,892 Other assets $ 1,971 $ 7,360 Accrued expense and other current liabilities $ 3,137 $ 481 Other non-current liabilities $ 3,075 $ 322 Derivatives not designated as hedging instruments : As of Foreign currency exchange contracts December 31, 2018 December 31, 2017 Other current assets $ 37 $ 46 Accrued expense and other current liabilities $ 67 $ 74 The following tables set forth the effect of foreign currency exchange contracts on the consolidated statements of income and accumulated other comprehensive loss for the years ended December 31, 2018 , 2017 and 2016 : Year ended December 31, Forward exchange contracts : 2018 2017 2016 (Loss)/gain recognized in AOCI Derivatives in cash flow hedging relationships $ (13,919 ) $ 19,802 $ 5,129 (Loss)/gain recognized in consolidated statements of income Derivatives not designated as hedging instruments $ (3,224 ) $ 5,056 $ 4,790 Location and amount of gain/(loss) recognized in consolidated statements of income for cash flow hedging relationships and derivatives not designated as hedging instruments Year ended December 31, 2018 2017 2016 As per consolidated statements of income Gain/(loss) on foreign currency exchange contracts As per consolidated statements of income Gain/(loss) on foreign currency exchange contracts As per consolidated statements of income Gain/(loss) on foreign currency exchange contracts Cash flow hedging relationships Location in consolidated statements of income where gain/(loss) was reclassed from AOCI Cost of revenues $ 584,855 $ 2,481 $ 495,142 $ 5,465 $ 447,718 $ — General & administrative expenses $ 116,202 $ 443 $ 102,515 $ 960 $ 88,616 $ — Selling & marketing expenses $ 63,612 $ 44 $ 53,379 $ 103 $ 50,579 $ — Depreciation & amortization $ 48,566 $ 181 $ 38,549 $ 371 $ 34,580 $ — Foreign exchange gain/(loss), net $ 4,787 $ — $ 2,839 $ — $ 5,597 $ 2,669 $ 3,149 $ 6,899 $ 2,669 Derivatives not designated as hedging instruments Location in consolidated statements of income where gain/(loss) was recognized Foreign exchange gain/(loss), net $ 4,787 $ (3,224 ) $ 2,839 $ 5,056 $ 5,597 $ 4,790 $ 4,787 $ (3,224 ) $ 2,839 $ 5,056 $ 5,597 $ 4,790

Borrowings and Credit Arrangeme

Borrowings and Credit Arrangements	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Borrowings and Credit Arrangements	Borrowings and Credit Arrangements Revolver Credit Agreement On October 24, 2014, the Company entered into a credit agreement that provided for a $50,000 revolving credit facility (the “Credit Facility”). On February 23, 2015, the Company increased the commitments under the Credit Facility by an additional $50,000 . The Credit Facility had a maturity date of October 24, 2019 and was voluntarily pre-payable from time to time without premium or penalty. On November 21, 2017, the Company prepaid all outstanding amounts, including accrued interest and fees, and terminated all commitments, under the Credit Agreement. The Credit Facility carried an effective interest rate of 2.99% per annum during the year ended December 31, 2017. On November 21, 2017, the Company and each of the Company’s wholly owned material domestic subsidiaries entered into a Credit Agreement with certain lenders, and Citibank, N.A. as Administrative Agent (the “New Credit Agreement”). The New Credit Agreement provides for a $200,000 revolving credit facility (the “New Credit Facility”) with an option to increase the commitments by up to $100,000 , subject to certain approvals and conditions as set forth in the New Credit Agreement. The New Credit Agreement also includes a letter of credit sub facility. The New Credit Facility has a maturity date of November 21, 2022 and is voluntarily pre-payable from time to time without premium or penalty. Borrowings under the New Credit Agreement were used to repay amounts outstanding under the Credit Facility and may otherwise be used for working capital and general corporate purposes, including permitted acquisitions. On July 2, 2018, the Company exercised its option under the New Credit Agreement to increase the commitments by $100,000 thereby utilizing the entire revolver under the New Credit Facility of $300,000 , to fund the SCIO acquisition. The incremental commitments were made pursuant to (and constitute part of) the existing commitments and are subject to the terms and conditions applicable to the existing commitments as set forth in the New Credit Agreement. Depending on the type of borrowing, loans under the New Credit Agreement bear interest at a rate equal to the specified prime rate (alternate base rate) or adjusted LIBO rate, plus, in each case, an applicable margin. The applicable margin is tied to the Company’s total net leverage ratio and ranges from 0% to 0.75% per annum with respect to loans pegged to the specified prime rate, and 1.00% to 1.75% per annum on loans pegged to the adjusted LIBO rate. The revolving credit commitments under the New Credit Agreement are subject to a commitment fee which is also tied to the Company’s total net leverage ratio, and ranges from 0.15% to 0.30% per annum on the average daily amount by which the aggregate revolving commitments exceed the sum of outstanding revolving loans and letter of credit obligations. The New Credit Facility carried an effective interest rate of 3.4% and 3.0% per annum, respectively, during the years ended December 31, 2018 and 2017. Obligations under the New Credit Agreement are guaranteed by the Company’s material domestic subsidiaries and are secured by all or substantially all of the assets of the Company and our material domestic subsidiaries. The New Credit Agreement contains customary affirmative and negative covenants, including, but not limited to, restrictions on the ability to incur indebtedness, create liens, make certain investments, make certain dividends and related distributions, enter into, or undertake, certain liquidations, mergers, consolidations or acquisitions and dispose of assets or subsidiaries. In addition, the New Credit Agreement contains a covenant to not permit the interest coverage ratio (the ratio of EBITDA to cash interest expense) or the total net leverage ratio (total funded indebtedness, less unrestricted domestic cash and cash equivalents not to exceed $50,000 to EBITDA) for the four consecutive quarter period ending on the last day of each fiscal quarter, to be less than 3.5 to 1.0 or more than 3.0 to 1.0, respectively. As of December 31, 2018, the Company was in compliance with all financial and non-financial covenants listed under the New Credit Agreement. The Company entered into a second amendment (the “Amendment”) to its New Credit Agreement, as amended, among the Company, as borrower, with certain lenders, and Citibank, N.A. as Administrative Agent to, among other things, permit the issuance by the Company of the convertible notes, and settlement upon maturity or conversion thereof, in accordance with the Investment Agreement, the indenture dated as of October 4, 2018 and the other documents entered into in connection therewith. As of December 31, 2018, the Company had outstanding indebtedness under the new credit facility of $150,000 of which $20,000 is expected to be repaid within the next twelve months and is included under “current portion of long-term borrowings” and of which $130,000 is included under “long-term borrowings” in the consolidated balance sheets. As of December 31, 2017, the Company had outstanding indebtedness under the new credit facility of $60,000 , of which $10,000 was included under “current portion of long-term borrowings,” and the balance of $50,000 was included under “long-term borrowings” in the consolidated balance sheets. The Company incurred certain debt issuance costs, which are deferred and amortized as an adjustment to interest expense over the term of the new credit facility. The unamortized debt issuance costs as of December 31, 2018 and December 31, 2017 was $1,006 and $773 , respectively and is included under “other current assets” and “other assets” in the consolidated balance sheets. Convertible Senior Notes On October 1, 2018, the Company entered into an investment agreement (the “Investment Agreement”) with Orogen Echo LLC (the “Purchaser”), an affiliate of The Orogen Group LLC, relating to the issuance to the Purchaser of $150,000 aggregate principal amount of 3.50% per annum Convertible Senior Notes due October 1, 2024 (the “Notes”). The transactions contemplated by the Investment Agreement, including the issuance of the Notes, closed on October 4, 2018. The Notes bear interest at a rate of 3.50% per annum, payable semi-annually in arrears in cash on April 1 and October 1 of each year. During the year ended December 31, 2018, the Company recognized interest expense of $1,313 . The Notes are convertible at an initial conversion rate of 13.3333 shares of the common stock per $1,000 principal amount of the Notes (which represents an initial conversion price of approximately $75 per share). With certain exceptions, upon a fundamental change, as defined in the Indenture, the holders of the Notes may require that the Company to repurchase all or part of the principal amount of the Notes at a purchase price equal to the principal amount plus accrued and unpaid interest. The Company may redeem the principal amount of the Notes, at its option, in whole but not in part, at a purchase price equal to the principal amount plus accrued and unpaid interest on or after October 1, 2021, if the closing sale price of the common stock exceeds 150% of the then-current conversion price for 20 or more trading days in the 30 consecutive trading day period preceding the Company’s exercise of this redemption right (including the trading day immediately prior to the date of the notice of redemption).The Company may elect to settle conversions of the Notes by paying or delivering, as the case may be, cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock. The Company used the proceeds from the issuance of Notes to repay $150,000 of its outstanding borrowings under the New Credit Facility. The net proceeds from the issuance of Notes were approximately $149,000 , after deducting debt issuance costs of $1,000 and offering expenses of approximately $325 paid by the Company. These transaction and debt issuance costs were allocated between the liability and equity components based on their relative values. The transaction costs and debt issuance costs allocated to the liability and equity components were $1,176 and $149 , respectively. The debt issuance costs allocated to the liability component are deferred and amortized as an adjustment to interest expense over the term of the Notes. The unamortized debt issuance costs is presented as a direct reduction from the Notes in the consolidated balance sheets. The unamortized debt issuance costs as of December 31, 2018 was $1,127 . The Company accounted for the liability and equity components of the Notes separately to reflect its non-convertible debt borrowing rate. The estimated fair value of the liability component at issuance of $133,077 was determined using a discounted cash flow technique, which considered debt issuances with similar features of the Company’s debt, excluding the conversion feature. The resulting effective interest rate for the Notes was 5.75% per annum. The excess of the gross proceeds received over the estimated fair value of the liability component totaling $16,923 was allocated to the conversion feature (equity component, recorded as additional paid-in capital) with a corresponding offset recognized as a discount to reduce the net carrying value of the Notes. The discount is being amortized to interest expense over a six -year period ending October 1, 2024 (the expected life of the liability component) using the effective interest method. During the year ended December 31, 2018, the Company amortized $600 of the discount to interest expense. At the time of issuance, the Company evaluated the Notes in accordance with ASC 815-15 and determined that the Notes contain a single embedded derivative, being the call option having market interest rates as underlying, which does not require bifurcation as the features clearly and closely related to the host instrument. The Company determined that the value of this embedded derivative was nominal as of the date of issuance. Borrowings also includes structured payables which are in the nature of debt, amounting to $2,114 and $709 as of December 31, 2018 and December 31, 2017, respectively, of which $1,423 and $318 is included under “current portion of long-term borrowings”, $691 and $391 , respectively, under “long-term borrowings” in the consolidated balance sheets. Future principal payments/maturities for all of the Company's borrowings as of December 31, 2018 were as follows: Notes Revolver Credit Structured Payables Total 2019 $ — $ 20,000 $ 1,423 $ 21,423 2020 — 28,000 691 28,691 2021 — 28,000 — 28,000 2022 — 74,000 — 74,000 2023 — — — — Thereafter 150,000 — — 150,000 Total $ 150,000 $ 150,000 $ 2,114 $ 302,114

Capital Structure

Capital Structure	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Capital Structure	Capital Structure Common Stock The Company has one class of common stock outstanding. During the year ended December 31, 2018 , 2017 and 2016 , the Company acquired 51,446 , 69,154 and 17,676 shares of common stock, respectively, from employees in connection with withholding tax payments related to the vesting of restricted stock for a total consideration of $3,122 , $3,267 and $807 , respectively. The weighted average purchase price per share of $60.68 , $47.24 and $45.65 , respectively, was the average of the high and low price of the Company's share of common stock on the Nasdaq Global Select Market on the trading day prior to the vesting date of the shares of restricted stock. On December 30, 2014, the Company’s Board of Directors authorized a common stock repurchase program (the “2014 Repurchase Program”), under which shares were authorized to be purchased by the Company from time to time from the open market and through private transactions during each of the fiscal years 2017 through 2019 up to an annual amount of $20,000 . On February 28, 2017, the Company’s Board of Directors authorized an additional common stock repurchase program (the “2017 Repurchase Program”), under which shares may be purchased by the Company from time to time from the open market and through private transactions during each of the fiscal years 2017 through 2019 up to an aggregate additional amount of $100,000 . The approval increased the 2017 authorization from $20,000 to $40,000 and authorizes stock repurchases of up to $40,000 in each of 2018 and 2019. During the year ended December 31, 2018 , the Company purchased 674,604 shares of its common stock for an aggregate purchase price of approximately $39,987 , including commissions, representing an average purchase price per share of $59.27 under the 2017 Repurchase Program. During the year ended December 31, 2017 , the Company purchased 761,154 shares of its common stock for an aggregate purchase price of approximately $40,187 , including commissions, representing an average purchase price per share of $52.80 under the 2014 and 2017 Repurchase Programs. During the year ended December 31, 2016 , the Company purchased 364,056 shares of its common stock for an aggregate purchase price of approximately $17,396 , including commissions, representing an average purchase price per share of $47.78 under the 2014 Repurchase Programs. Repurchased shares have been recorded as treasury shares and will be held until the Board of Directors designates that these shares be retired or used for other purposes. Dividends The Company has not paid or declared any cash dividends on its common stock during the years ended December 31, 2018, 2017 and 2016. The Company’s line of credit with a bank could restrict, or its terms of the Notes could impair, the Company’s ability to declare or make any dividends or similar distributions.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans The Company’s Gratuity Plans in India ("Gratuity Plan") provide for lump sum payment to vested employees on retirement or upon termination of employment in an amount based on the respective employee’s salary and years of employment with the Company. Liabilities with regard to the Gratuity Plans are determined by actuarial valuation using the projected unit credit method. Current service costs for the Gratuity Plan are accrued in the year to which they relate. Actuarial gains or losses or prior service costs, if any, resulting from amendments to the plans are recognized and amortized over the remaining period of service of the employees. In addition, the Company’s subsidiary operating in the Philippines conforms to the minimum regulatory benefit which provide for lump sum payment to vested employees on retirement from employment in an amount based on the respective employee’s salary and years of employment with the Company (the "Philippines Plan"). The benefit costs of the Philippines Plan for the year are calculated on an actuarial basis. The benefit obligation has been measured as of December 31, 2018 . The following table sets forth the activity and the funded status of the Gratuity Plans and the amounts recognized in the Company’s consolidated financial statements at the end of the relevant periods: 2018 2017 Change in projected benefit obligation: Projected benefit obligation as of January 1 $ 10,305 $ 9,711 Business acquisition 326 — Service cost 1,735 1,933 Interest cost 714 645 Benefits paid (1,066 ) (1,001 ) Actuarial (gain)/loss (134 ) (1,471 ) Effect of exchange rate changes (836 ) 488 Projected benefit obligation as of December 31 $ 11,044 $ 10,305 Unfunded amount–non-current $ 3,616 $ 3,377 Unfunded amount–current 8 13 Total accrued liability $ 3,624 $ 3,390 Accumulated benefit obligation $ 7,239 $ 7,022 Components of net periodic benefit costs: Year ended December 31, 2018 2017 2016 Service cost $ 1,735 $ 1,933 $ 1,601 Interest cost 714 645 599 Expected return on plan assets (514 ) (401 ) (416 ) Amortization of actuarial (gain)/loss (153 ) 256 90 Net periodic benefit cost $ 1,782 $ 2,433 $ 1,874 Effective January 1, 2018, the Company adopted ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost . Pursuant to this, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the 2017 and 2016 consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The interest cost, expected return on plan assets and amortization of actuarial (gain)/loss, have been reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. Refer Note 27 for the effect of the adoption of the ASU No. 2017-07 on 2017 and 2016 financial information. The components of accumulated other comprehensive gain/(loss), net of tax as of December 31, 2018 and 2017 are as follows: December 31, 2018 2017 2016 Net actuarial gain/(loss) $ 940 $ 697 $ (831 ) Net prior service cost (22 ) (8 ) (9 ) Deferred taxes 53 74 342 Accumulated other comprehensive gain/(loss), net of tax $ 971 $ 763 $ (498 ) The amount in accumulated other comprehensive gain that is expected to be recognized as a component of net periodic benefit cost over the next fiscal year is $156 . The weighted average actuarial assumptions used to determine benefit obligations and net periodic gratuity cost are: December 31, 2018 2017 2016 Discount rate 7.5 % 7.0 % 6.8 % Rate of increase in compensation levels 8.2 % 9.1 % 9.2 % Expected long term rate of return on plan assets per annum 7.3 % 8.3 % 9.0 % The Company evaluates these assumptions annually based on its long-term plans of growth and industry standards. The discount rates are based on current market yields on government securities adjusted for a suitable risk premium. Expected benefit payments during the year ending December 31, 2019 $ 1,820 2020 $ 1,692 2021 $ 1,621 2022 $ 1,424 2023 $ 1,332 2024 to 2028 $ 4,577 The gratuity plan in India is partially funded and the Philippines Plan is unfunded. The Company makes annual contributions to the employees’ gratuity fund established with Life Insurance Corporation of India and HDFC Standard Life Insurance Company. They calculate the annual contribution required to be made by the Company and manage the Gratuity Plans, including any required payouts. Fund managers manage these funds on a cash accumulation basis and declare interest retrospectively on March 31 of each year. The Company earned a return of approximately 8.0% on these Gratuity Plans for the year ended December 31, 2018. Change in Plan Assets Plan assets at January 1, 2017 $ 5,640 Actual return 202 Employer contribution 1,700 Benefits paid* (1,001 ) Effect of exchange rate changes 374 Plan Assets at December 31, 2017 $ 6,915 Business acquisition 231 Actual return 779 Employer contribution 1,175 Benefits paid* (1,059 ) Effect of exchange rate changes (621 ) Plan assets at December 31, 2018 $ 7,420 * Benefits payments were substantially made through the plan assets during the year ended December 31, 2018 and December 31, 2017. The Company maintains several 401(k) plans (the “401(k) Plans”) under Section 401(k) of the Internal Revenue Code of 1986 (the “Code”), covering all eligible employees, as defined in the Code as a defined contribution plan. The Company may make discretionary contributions of up to a maximum of 4% of employee compensation within certain limits. Contributions to the 401(k) Plans amounted to $3,423 , $2,709 and $2,383 during the years ended December 31, 2018 , 2017 and 2016 , respectively. During the years ended December 31, 2018 , 2017 and 2016 , the Company contributed $7,614 , $7,116 and $6,306 respectively, for various defined contribution plans on behalf of its employees in India, the Philippines, Bulgaria, Romania, the Czech Republic, South Africa, Colombia, and Singapore.

Leases

Leases	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Leases	Leases The Company finances its use of certain motor vehicles and other equipment under various lease arrangements provided by financial institutions. Future minimum lease payments under these capital leases as of December 31, 2018 are as follows: During the next twelve months ending December 31, 2019 $ 283 2020 163 2021 120 2022 58 2023 and thereafter 49 Total minimum lease payments 673 Less: amount representing interest 135 Present value of minimum lease payments 538 Less: current portion 223 Long term capital lease obligation $ 315 The Company conducts its operations using facilities leased under operating lease agreements that expire at various dates. Future minimum lease payments under such agreements expiring after December 31, 2018 are set forth below: During the next twelve months ending December 31, 2019 $ 23,431 2020 20,039 2021 16,924 2022 14,804 2023 12,859 2024 and thereafter 26,114 Future minimum lease payment $ 114,171 Rent expense The operating leases are subject to renewal periodically and have scheduled rent increases. The Company recognizes rent expense on such leases on a straight-line basis over cancelable and non-cancelable lease period determined under ASC Topic 840, Leases : Year ended December 31, 2018 2017 2016 Rent expense $ 25,573 $ 24,015 $ 21,382 Deferred rent As of December 31, 2018 December 31, 2017 Cancelable and non-cancelable operating leases $ 8,782 $ 8,959 Deferred rent is included under “Accrued expenses and other current liabilities” and “Other non-current liabilities” in the consolidated balance sheets.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income before income taxes consist of the following: Year ended December 31, 2018 2017 2016 Domestic $ (24,442 ) $ 4,626 $ 12,652 Foreign 84,812 80,408 71,232 $ 60,370 $ 85,034 $ 83,884 The income tax expense consists of the following: Year ended December 31, 2018 2017 2016 Current provision: Domestic $ (13,249 ) $ 17,407 $ 7,107 Foreign 17,271 18,008 18,428 $ 4,022 $ 35,415 $ 25,535 Deferred provision/(benefit): Domestic $ (1,999 ) $ 2,618 $ (2,506 ) Foreign 1,374 (1,887 ) (878 ) $ (625 ) $ 731 $ (3,384 ) Income tax expense $ 3,397 $ 36,146 $ 22,151 The effective income tax rate differs from the amount computed by applying the U.S. federal statutory income tax rate to income before income taxes approximately as follows: Year ended December 31, 2018 2017 2016 Expected tax expense $ 12,678 $ 29,762 $ 29,361 Change in valuation allowance — (21 ) 22 Impact of tax holiday (5,448 ) (4,396 ) (4,027 ) Foreign tax rate differential 5,014 (2,616 ) (2,716 ) Deferred tax (benefit)/provision (3,915 ) (1,887 ) (878 ) Unrecognized tax benefits and interest (88 ) (3,905 ) 495 State taxes, net of Federal taxes 2,200 339 202 Non-deductible expenses 3,066 825 144 US Tax Reform Act impact 176 29,185 — Excess tax benefit on stock-based compensation (7,227 ) (9,797 ) — Research & Development credit (1,500 ) (844 ) (890 ) Other (1,559 ) (499 ) 438 Tax expense $ 3,397 $ 36,146 $ 22,151 The Company recorded income tax expense of $3,397 and $36,146 for the year ended December 31, 2018 and 2017, respectively. The effective tax rate decreased from 42.5% during the year ended December 31, 2017 to 5.6% during the year ended December 31, 2018 primarily as a result of: (i) reduction in federal statutory tax rate and (ii) the impact of one-time transition tax of $27,236 on the mandatory deemed repatriation of accumulated earnings and profits (“E&P”) of foreign subsidiaries and deferred tax re-measurement of $1,949 under the Tax Cuts and Jobs Act (the “Tax Reform Act”), during the year ended December 31, 2017 compared to $176 during the year ended December 31, 2018. The SEC staff issued Staff Accounting Bulletin ("SAB 118"), which provides guidance on accounting for the tax effects of the Tax Reform Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Reform Act enactment date for companies to complete the accounting under ASC 740, Income Taxes (“ASC 740”). In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Reform Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Reform Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Reform Act. The deemed repatriation transition tax (the “Transition Tax”) is a tax on certain previously untaxed accumulated and current earnings & profits of the Company's foreign subsidiaries. The Company was able to reasonably estimate the Transition Tax and recorded an initial provisional Transition Tax obligation of $27,236 , with a corresponding adjustment of $27,236 to income tax expense for the year ended December 31, 2017. On the basis of additional technical research and analysis, the Company recognized a measurement-period increase of $176 to the Transition Tax obligation, with a corresponding adjustment of $176 to the income tax expense during year ended December 31, 2018. The Company has completed its analysis of the transition tax and has recorded a final Transition Tax obligation of $27,412 with a corresponding income tax expense of $27,412 . During the first quarter of 2018, the Company made an election to change the tax status of most of its controlled foreign corporations (CFC) to disregarded entities for US income tax purposes. As a result, the Company no longer has undistributed earnings in connection with these CFCs. The Transition Tax resulted in previously taxed income (PTI) which may be subject to withholding taxes and currency gains or losses upon repatriation. The Company presently does not intend to distribute its PTI and has not recorded any deferred taxes. If, in the future, the Company changes its present intention regarding the distribution of PTI, additional taxes may be required and would be recorded in the period the intention changes. The Company has adopted an accounting policy to treat Global Intangible Low-Taxed Income (GILTI) as a period cost. As of December 31, 2017, the Company was able to reasonably estimate and record initial provisional adjustments associated with the corporate rate change in the amount of $1,949 . The Company has completed its analysis and no significant adjustment was recorded related to this item during the year ended December 31, 2018. Certain operations centers in India, which were established in Special Economic Zones (“SEZs”), are eligible for tax incentives until 2025. These operations centers are eligible for a 100% income tax exemption for first 5 years of operations and 50% exemption for a period of 5 years thereafter. The Company has also benefitted from a corporate tax holiday in the Philippines for our operations centers established there over the last several years. The tax holiday expired for three of our centers in 2014, 2016 and in 2018 and will expire for other centers by year 2022, which may lead to an increase in our overall tax rate. Following the expiry of the tax exemption, income generated from centers in the Philippines will be taxed at the prevailing annual tax rate, which is currently 5.0% on gross income. The diluted earnings per share effect of the tax holiday is $0.16 , $0.13 and $0.12 for the years ended December 31, 2018 , 2017 and 2016 , respectively. The components of the deferred tax balances as of December 31, 2018 and 2017 are as follows: As of December 31, 2018 December 31, 2017 Deferred tax assets: Depreciation and amortization $ 3,731 $ 2,183 Stock-based compensation 8,614 7,647 Accrued employee costs and other expenses 3,596 3,673 Tax credit carry forward — 1,474 Net operating loss carry forward 1,113 2,068 Unrealized exchange loss 6,671 252 Deferred rent 2,255 2,064 Others 1,380 1,007 $ 27,360 $ 20,368 Valuation allowance (99 ) (108 ) Deferred tax assets $ 27,261 $ 20,260 Deferred tax liabilities: Unrealized exchange gain $ 115 $ 5,069 Intangible assets 19,289 4,648 Unamortized discount on convertible senior notes 4,105 — Others 5,595 1,958 Deferred tax liabilities $ 29,104 $ 11,675 Net deferred tax assets/(liabilities) $ (1,843 ) $ 8,585 Deferred tax assets and liabilities are recognized for future tax consequences attributable to temporary differences between the financial statement carrying values of assets and liabilities and their respective tax bases and operating loss carry forwards. At December 31, 2018 and 2017 , the Company performed an analysis of the deferred tax asset valuation allowance for net operating loss carry forward for its domestic and foreign entities. Based on this analysis, the Company continues to carry a valuation allowance on the deferred tax assets on certain net operating loss carry forwards. Accordingly, the Company had recorded a valuation allowance of $20 each as of December 31, 2018 and 2017 . The Company also recorded a valuation allowance of $79 and $88 related to tax credit carry forward as of December 31, 2018 and 2017 , respectively. The Company in connection with its recent acquisitions has acquired federal and state net operating losses in the United States. As of December 31, 2018 and 2017 , the Company has federal net operating loss carry forward of $444 and $1,554 , respectively, which expire through various years until 2032 . The Company’s federal net operating losses carry forward are subject to certain annual utilization limitations under Section 382 of the Code. The Company also has state and local net operating losses carry forwards of varying amounts, which are subject to limitations under the applicable rules and regulations of those taxing jurisdictions. The Company estimates that it will be able to utilize substantially all of the losses before their expiration. The Company’s income tax expense also includes the impact of provisions established for uncertain income tax positions determined in accordance with ASC 740 as well as the related net interest. Tax exposures can involve complex issues and may require an extended resolution period. Although the Company believes that it has adequately reserved for its uncertain tax positions, no assurance can be given that the final tax outcome of these matters will not be different. The Company adjusts these reserves in light of changing facts and circumstances, such as the closing of a tax audit or the refinement of an estimate. To the extent that the final tax outcome of these matters differs from the amounts recorded, such differences will impact the income tax expense in the period in which such determination is made. The following table summarizes the activity related to the unrecognized tax benefits for the years ended December 31, 2018 , 2017 and 2016 . 2018 2017 2016 Balance as of January 1 $ 824 $ 3,087 $ 2,797 Increases related to prior year tax positions — — 156 Decreases related to prior year tax positions (320 ) (2,520 ) — Increases related to current year tax positions 300 169 178 Effect of exchange rate changes — 88 (44 ) Balance as of December 31 $ 804 $ 824 $ 3,087 The unrecognized tax benefits as of December 31, 2018 of $804 , if recognized, would impact the effective tax rate. The Company has no t recognized any interest in each of the years ended December 31, 2018 and 2017 and has recognized interest of $315 during the year ended December 31, 2016. As of December 31, 2018 and 2017 , the Company has accrued interest and penalties of $ nil and $68 relating to unrecognized tax benefits.

Stock Based Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	Stock Based Compensation On June 15, 2018, at the Company’s 2018 Annual Meeting of Stockholders, the Company's stockholders approved the 2018 Plan, which replaced and superseded the 2015 Plan, which was an amendment and restatement of the Company’s 2006 Omnibus Award Plan to, among other things, reserves 3,175,000 shares of the Company’s common stock for grants of awards under the 2018 Plan. As of December 31, 2018, the Company had 3,207,975 shares available for grant under the 2018 Plan (includes 34,487 shares against vested performance-based restricted stock units for which the underlying common stock was issued subsequent to December 31, 2018). Under the 2018 Plan, the Compensation Committee (the “Committee”) may grant awards of non-qualified stock options, incentive stock options, stock appreciation rights, restricted stock, restricted stock units, stock bonus awards, performance based compensation awards (including cash bonus awards and market condition based awards) or any combination of the foregoing. The Committee determines which employees are eligible to receive the equity awards, the number of equity awards to be granted, the exercise price, the vesting period and the exercise period. The vesting period for the equity award issued is determined on the date of the grant and is non-transferable during the life of the equity award. The majority of options expire ten years from the date of grant. The equity awards generally vest proportionally over a period of four years from the date of grant, unless specified otherwise. The Company applies the provisions of ASC 718, Compensation - Stock Compensation , to account for its stock based compensation, using the modified prospective method of transition. Under the provisions of this guidance, the estimated fair value of stock-based awards granted under stock incentive plans is recognized as compensation expense over the vesting period. The following costs related to the Company’s stock-based compensation plan are included in the consolidated statements of income: Year ended December 31, 2018 2017 2016 Cost of revenues $ 4,924 $ 4,600 $ 3,664 General and administrative expenses 10,371 10,363 8,372 Selling and marketing expenses 8,606 8,078 7,734 Total $ 23,901 $ 23,041 $ 19,770 Stock Options The fair value of each stock option granted to employees is estimated on the date of grant using the Black-Scholes option-pricing model. The Company does not anticipate paying any cash dividends in the foreseeable future and therefore uses an expected dividend yield of zero in the option valuation model. All stock-based payment awards are amortized on a straight-line basis over the requisite service periods of the awards, which are generally the vesting periods. The Company accounts for the forfeitures as and when the actual forfeitures occur. Stock option activity under the Company’s stock-based compensation plans is shown below: Number of Weighted- Aggregate Weighted- Outstanding at December 31, 2017 259,563 $ 18.03 $ 10,985 2.76 Granted — — — — Exercised (97,088 ) 14.39 4,446 — Forfeited — — — — Outstanding at December 31, 2018 162,475 $ 20.21 $ 5,267 2.24 Vested and exercisable at December 31, 2018 162,475 $ 20.21 $ 5,267 2.24 The unrecognized compensation cost for unvested options as of December 31, 2018 is $ nil . The Company did not grant any options during the years ended December 31, 2018, 2017 and 2016. The total grant date fair value of options vested during the years ended December 31, 2018 , 2017 and 2016 was $ nil , $ nil and $706 , respectively. The aggregate intrinsic value of options exercised during the years ended December 31, 2018 , 2017 and 2016 was $4,446 , $23,027 and $12,911 , respectively. The following table summarizes the status of the Company’s stock options outstanding, vested and exercisable at December 31, 2018 : Options Outstanding, Vested and Exercisable Range of Exercise Prices Shares Weighted- Average Exercise Price $8.00 to $15.00 35,500 $ 9.53 $15.01 to $21.00 25,466 18.74 $21.01 to $28.00 101,509 24.30 Total 162,475 $ 20.21 Restricted Stock and Restricted Stock Units An award of restricted stock is a grant of shares subject to conditions and restrictions set by the Committee. The grant or the vesting of an award of restricted stock may be conditioned upon service to the Company or its affiliates or upon the attainment of performance goals or other factors, as determined in the discretion of the Committee. The Committee may also, in its discretion, provide for the lapse of restrictions imposed upon an award of restricted stock. Holders of an award of restricted stock may have, with respect to the restricted stock granted, all of the rights of a stockholder, including the right to vote and to receive dividends. The Committee is authorized to award restricted stock units to participants. The Committee establishes the terms, conditions and restrictions applicable to each award of restricted stock units, including the time or times at which restricted stock units will be granted or vested and the number of units to be covered by each award. The terms and conditions of each restricted stock award will be reflected in a restricted stock unit agreement. Any cash or in-kind dividends paid with respect to unvested shares of restricted stock and restricted stock units are withheld by the Company and paid to the holder of such shares of restricted stock, without interest, only if and when such shares of restricted stock and restricted stock units vest. Any unvested shares of restricted stock and restricted stock units are immediately forfeited without consideration upon the termination of holder’s employment with the Company or its affiliates. Accordingly, the Company’s unvested restricted stock and restricted stock units do not include non-forfeitable rights to dividends or dividend equivalents and are therefore not considered as participating securities for purposes of earnings per share calculations pursuant to the two-class method. Restricted stock and restricted stock unit activity under the Company’s stock-based compensation plans is shown below: Restricted Stock Restricted Stock Units Number Weighted- Average Fair Value Number Weighted- Average Fair Value Outstanding at December 31, 2017 * 182,267 $ 42.64 1,046,999 $ 42.26 Granted — — 444,063 60.64 Vested (69,714 ) 40.38 (444,470 ) 38.36 Forfeited (8,930 ) 59.77 (93,014 ) 50.75 Outstanding at December 31, 2018 * 103,623 $ 42.68 953,578 $ 51.81 * Excludes 9,641 and 11,058 restricted stock units vested during the years ended December 31, 2018 and 2017 , respectively. As of December 31, 2018 and 2017 restricted stock units vested for which the underlying common stock is yet to be issued are 155,753 and 146,112 , respectively. The fair value of restricted stock and restricted stock units is generally the market price of the Company’s shares on the date of grant. As of December 31, 2018 , unrecognized compensation cost of $36,460 is expected to be expensed over a weighted average period of 2.55 years . The weighted-average fair value of restricted stock and restricted stock units granted during the years ended December 31, 2018 , 2017 and 2016 was $60.64 , $48.02 and $48.97 , respectively. The total grant date fair value of restricted stock and restricted stock units vested during the years ended December 31, 2018 , 2017 and 2016 was $19,865 , $19,430 and $10,761 , respectively. Performance Based Stock Awards Under the 2018 Plan, the Company grants performance-based restricted stock units (“PRSUs”) to executive officers and other specified employees. 50% of the PRSUs cliff vest at the end of a three -year period based on a revenue target for the third year (“PUs”). However, for PUs granted in 2018, up to one-third of the PUs may be earned based on the Company’s revenue performance in each of the first two years against annual revenue targets in those years. The total amount of PUs that the recipient earns based on these performance criteria will be the greater of (i) the PUs earned in the year of vesting and (ii) the sum of the earned PUs during the first two years. The remaining 50% is based on a market condition (“MUs”) that is contingent on the Company's meeting the total shareholder return relative to a group of peer companies specified under the program measured over a three -year performance period. The award recipient may earn up to two hundred percent ( 200% ) of the PRSUs granted based on the actual achievement of targets. The fair value of each PU was determined based on the market price of one common share on a day prior to the date of grant, and the associated stock compensation expense was calculated on the basis that performance targets at 100% are probable of being achieved. The stock compensation expense for the PUs is recognized on a straight-line basis over the service period, which is through the end of the third year. Over this period, the number of shares that will be issued will be adjusted upward or downward based upon the probability of achievement of the performance targets. The ultimate number of shares issued and the related compensation cost recognized as an expense will be based on a comparison of the final performance metrics to the specified targets. The grant date fair value for the MUs was determined using a Monte Carlo simulation model and the related stock compensation expense was expensed on a straight-line basis over the vesting period. All stock compensation expense related to the MUs will be recognized if the requisite performance period is fulfilled, even if the market condition is not achieved. The Monte Carlo simulation model simulates a range of possible future stock prices and estimates the probabilities of the potential payouts. This model also incorporates the following ranges of assumptions: • The historical volatilities are used over the most recent three-year period for the components of the peer group. • The risk-free interest rate is based on the U.S. Treasury rate assumption commensurate with the three-year performance period • Since the plan stipulates that the awards are based upon the TSR of the Company and the components of the peer group, it is assumed that the dividends get reinvested in the issuing entity on a continuous basis. • The correlation coefficients are used to model the way in which each entity tends to move in relation to each other are based upon the price data used to calculate the historical volatilities. The fair value of each MU granted to employees is estimated on the date of grant using the following weighted average assumptions: Year ended December 31, 2018 2017 2016 Dividend yield — — — Expected life (years) 2.86 2.86 2.85 Risk free interest rate 2.38 % 1.40 % 0.88 % Volatility 21.79 % 23.78 % 28.00 % Performance restricted stock unit activity under the Company’s stock plans is shown below: Revenue Based PRSUs Market Condition Based PRSUs Number Weighted Avg Fair Value Number Weighted Avg Fair Value Outstanding at December 31, 2017 113,190 $ 48.13 113,174 $ 60.80 Granted 55,268 60.58 55,262 70.97 Adjustment upon final determination of level of performance goal achievement* (44,467 ) 48.57 (14,896 ) 67.94 Vested (2,459 ) 48.57 (32,028 ) 67.94 Forfeited (21,179 ) 51.51 (21,176 ) 63.78 Outstanding at December 31, 2018 100,353 $ 54.07 100,336 $ 62.43 * Represents adjustment of shares issued in respect of PUs and MUs granted in February 2016 upon certification of the level of achievement of the performance targets for such awards for which the underlying common stock was issued subsequent to December 31, 2018. As of December 31, 2018 , unrecognized compensation cost of $7,652 is expected to be expensed over a weighted average period of 1.74 years .

Related Party Disclosures

Related Party Disclosures	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Disclosures	Related Party Disclosures The Company provides consulting services to PharmaCord, LLC. One of the Company’s directors, Nitin Sahney, is the member-manager and chief executive officer of PharmaCord, LLC. The Company recognized revenue of $225 , $1,748 and $ nil for the year ended December 31, 2018, 2017 and 2016, respectively, for services provided. As of December 31, 2018 and 2017, the Company had accounts receivable of $5 and $140 , respectively, related to these services. On October 1, 2018, the Company entered into the Investment Agreement with the Purchaser relating to the issuance to the Purchaser of $150,000 aggregate principal amount of the Notes. In connection with the investment, Vikram S. Pandit, Chairman and CEO of The Orogen Group LLC (an affiliate of the Purchaser), was appointed to Company’s Board of Directors. Refer Note 19 to the consolidated financial statements for details. At December 31, 2018, the Company had outstanding Notes with a principle amount of $150,000 and interest accrued of $1,313 related to the Investment Agreement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Fixed Asset Commitments At December 31, 2018 , the Company has committed to spend approximately $6,277 under agreements to purchase fixed assets. This amount is net of capital advances paid in respect of these purchases. Other Commitments Certain units of the Company’s Indian subsidiaries were established as 100% Export-Oriented units or under the Software Technology Parks of India (“STPI”) scheme promulgated by the Government of India. These units are exempt from customs, central excise duties, and levies on imported and indigenous capital goods, stores, and spares. The Company has undertaken to pay custom duties, service taxes, levies, and liquidated damages payable, if any, in respect of imported and indigenous capital goods, stores and spares consumed duty free, in the event that certain terms and conditions are not fulfilled. The Company’s management believes, however, that these units have in the past satisfied and will continue to satisfy the required conditions. The Company’s operations centers in the Philippines are registered with the Philippine Economic Zone Authority (“PEZA”). The registration provides the Company with certain fiscal incentives on the import of capital goods and requires ExlService Philippines, Inc. to meet certain performance and investment criteria. The Company’s management believes that these centers have in the past satisfied and will continue to satisfy the required criteria. In March 2017, the Company was named as a defendant in a putative class action lawsuit filed in California, which challenged the classification of independent contractors. The parties participated in a mediation in early 2018. As the result of the mediation, a settlement was reached pursuant to which the Company agreed, without admission of wrongdoing, to pay a total of $2,400 , of which $1,200 was paid in 2018 and the remainder of which will be paid in 2019. Completion of all matters associated with the lawsuit is expected to occur on or before March 31, 2019. Contingencies U.S. and Indian transfer pricing regulations require that any international transaction involving associated enterprises be at an arm’s-length price. Accordingly, the Company determines the appropriate pricing for the international transactions among its associated enterprises on the basis of a detailed functional and economic analysis involving benchmarking against transactions among entities that are not under common control. The tax authorities have jurisdiction to review this arrangement and in the event that they determine that the transfer price applied was not appropriate, the Company may incur increased tax liability, including accrued interest and penalties. The Company is currently involved in disputes with the Indian tax authorities over the application of some of its transfer pricing policies for some of its subsidiaries. Further, the Company and a U.S. subsidiary are engaged in tax litigation with the income-tax authorities in India on the issue of permanent establishment. The Company is subject to taxation in the United States and various states and foreign jurisdictions. For the US and India, tax year 2015 and subsequent tax years remain open for examination by the tax authorities as of December 31, 2018. The aggregate amount demanded by Income tax authorities (net of advance payments, if any) from the Company related to its transfer pricing issues for tax years 2003 to 2014 and its permanent establishment issues for tax years 2003 to 2007 as of December 31, 2018 and 2017 is $18,177 and $18,065 , respectively, of which the Company has made payments or provided bank guarantee to the extent $8,171 and $8,573 , respectively. Amounts paid as deposits in respect of such assessments aggregating to $6,273 and $6,499 as of December 31, 2018 and 2017 , respectively, are included in “Other assets” and amounts deposited for bank guarantees aggregating to $1,899 and $2,074 as of December 31, 2018 and 2017 , respectively, are included in “Restricted cash” in the non-current assets section of the Company’s consolidated balance sheets. Based on the facts underlying the Company’s position and its experience with these types of assessments, the Company believes that its position will more likely than not be sustained upon final examination by the tax authorities based on its technical merits as of the reporting date and accordingly has not accrued any amount with respect to these matters in its consolidated financial statements. The Company does not expect any impact from these assessments on its future income tax expense. It is possible that the Company might receive similar orders or assessments from tax authorities for subsequent years. Accordingly, even if these disputes are resolved, the Indian tax authorities may still serve additional orders or assessments.

Impact of Adoption of Accountin

Impact of Adoption of Accounting Guidance on Prior Years Presentation and Disclosures (Notes)	12 Months Ended
	Dec. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Impact of adoption of accounting guidance on prior years’ presentation and disclosures	Impact of adoption of accounting guidance on prior years’ presentation and disclosures Effective January 1, 2018, the Company adopted ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715), Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post Retirement Benefit Cost . Accordingly, for 2017 and 2016, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The other components of net periodic benefit cost, which included interest cost, expected return on plan assets and amortization of actuarial gains/loss, were reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. The effect of the adoption of ASU No. 2017-07 (Topic 715) on 2017 and 2016 financial information is summarized as follows: Year ended December 31, Year ended December 31, 2017 2016 Previously reported As revised Effect of change Increase/(Decrease) Previously reported As revised Effect of change Increase/(Decrease) Location in consolidated statements of income Cost of revenues $ 495,586 $ 495,142 $ (444 ) $ 447,956 $ 447,718 $ (238 ) General and administrative expenses $ 102,567 $ 102,515 $ (52 ) $ 88,648 $ 88,616 $ (32 ) Selling and marketing expenses $ 53,383 $ 53,379 $ (4 ) $ 50,582 $ 50,579 $ (3 ) Other income, net $ 11,859 $ 11,359 $ (500 ) $ 15,408 $ 15,135 $ (273 ) Year ended December 31, Year ended December 31, 2017 2016 Cost of revenues previously reported Cost of revenues as revised Effect of change Increase/(Decrease) Cost of revenues previously reported Cost of revenues as revised Effect of change Increase/(Decrease) Segment information (refer Note 3) Insurance $ 159,529 $ 159,433 $ (96 ) $ 146,203 $ 146,151 $ (52 ) Healthcare $ 49,483 $ 49,412 $ (71 ) $ 44,098 $ 44,060 $ (38 ) TT&L $ 41,409 $ 41,337 $ (72 ) $ 41,962 $ 41,923 $ (39 ) F&A $ 51,445 $ 51,362 $ (83 ) $ 48,302 $ 48,258 $ (44 ) All Other $ 56,697 $ 56,638 $ (59 ) $ 61,050 $ 61,019 $ (31 ) Analytics $ 137,023 $ 136,960 $ (63 ) $ 106,341 $ 106,307 $ (34 ) Operating Expenses $ 194,499 $ 194,443 $ (56 ) $ 173,810 $ 173,775 $ (35 ) Foreign exchange gain, interest expense and other income, net $ 12,809 $ 12,309 $ (500 ) $ 19,662 $ 19,389 $ (273 ) Effective January 1, 2018, the Company adopted ASU 2016-18, Statements of Cash Flows (Topic 230), Restricted Cash. Accordingly, for 2017 and 2016, restricted cash and restricted cash equivalents is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown in the consolidated statements of cash flows. The effect of the adoption of ASU No. 2016-18 (Topic 230) on 2017 and 2016 financial information is summarized as follows: Year ended December 31, Year ended December 31, 2017 2016 Previously reported As revised Effect of change Increase/(Decrease) Previously reported As revised Effect of change Increase/(Decrease) Consolidated statements of cash flows Net cash provided by operating activities $ 113,140 $ 113,159 $ 19 $ 100,258 $ 102,395 $ 2,137 Effect of exchange rate changes on cash, cash equivalents and restricted cash $ 3,711 $ 3,935 $ 224 $ (5,033 ) $ (5,122 ) $ (89 ) Net increase/(decrease) in cash, cash equivalents and restricted cash $ (126,360 ) $ (126,117 ) $ 243 $ 7,832 $ 9,880 $ 2,048 Cash, cash equivalents and restricted cash - beginning of year $ 213,155 $ 220,394 $ 7,239 $ 205,323 $ 210,514 $ 5,191 Cash, cash equivalents and restricted cash - end of year $ 86,795 $ 94,277 $ 7,482 $ 213,155 $ 220,394 $ 7,239

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Preparation	The consolidated financial statements have been prepared in conformity with United States generally accepted accounting principles (“US GAAP”).
Principles of Consolidation	The accompanying financial statements have been prepared on a consolidated basis and reflect the financial statements of ExlService Holdings and all of its subsidiaries and includes the Company's share in the results of its associates. The standalone financial statements of subsidiaries are fully consolidated on a line-by-line basis. Intra-group balances and transactions, and income and expenses arising from intra-group transactions, are eliminated while preparing those financial statements. Accounting policies of the respective individual subsidiary and associate are aligned wherever necessary, so as to ensure consistency with the accounting policies that are adopted by the Company under US GAAP. The Company’s investments in equity affiliates are initially recorded at cost and any excess cost over proportionate share of the fair value of the net assets of the investee at the acquisition date is recognized as goodwill. The proportionate share of net income or loss of the investee is recognized in the consolidated statements of income. Non-controlling interest is the equity in a subsidiary not attributable, directly or indirectly, to the parent and it represents the minority partner’s interest in the operations of ExlService Colombia S.A.S. Non-controlling interest consists of the amount of such interest at the date of obtaining control over the subsidiary, and the non-controlling interest's share of changes in equity since that date. The non-controlling interests in the operations for the years ended December 31, 2018, 2017 and 2016 were insignificant and is included under general and administrative expenses in the consolidated statements of income.
Use of Estimates	The preparation of the consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the consolidated statements of income during the reporting period. Although these estimates are based on management’s best assessment of the current business environment, actual results may be different from those estimates. The significant estimates and assumptions that affect the consolidated financial statements include, but are not limited to, allowance for doubtful receivables, expected recoverability from customers with contingent fee arrangements, recoverability of dues from statutory authorities, assets and obligations related to employee benefit plans, deferred tax valuation allowances, income-tax uncertainties and other contingencies, valuation of derivative financial instruments, assumptions used to calculate stock-based compensation expense, depreciation and amortization periods, purchase price allocation, recoverability of long-term assets including goodwill and intangibles, and estimated costs to complete fixed price contracts.
Foreign Currency Translation	The functional currency of each entity in the Company is its respective local country currency which is also the currency of the primary economic environment in which it operates except for the entities in Mauritius which use the U.S. dollar as its functional currency. Transactions in foreign currencies are initially recorded into functional currency at the rates of exchange prevailing on the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are remeasured into functional currency at the rates of exchange prevailing at the balance sheet date. Non-monetary assets and liabilities are remeasured to the functional currency of the subsidiary at historical exchange rates. All transaction foreign exchange gains and losses are recorded in the accompanying consolidated statements of income. The assets and liabilities of the subsidiaries for which the functional currency is other than the U.S. dollar are translated into U.S. dollars, the reporting currency, at the rate of exchange prevailing on the balance sheet date. Revenues and expenses are translated into U.S. dollars at the exchange rates prevailing on the last business day of each month, which approximates the average monthly exchange rate. Resulting translation adjustments are included in accumulated other comprehensive loss in the consolidated balance sheet.
Revenue Recognition	Revenue is recognized when services are provided to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for our services. Revenue is measured based on consideration specified in a contract with a customer and excludes discounts and amounts collected on behalf of third parties. The Company recognizes revenue when it satisfies a performance obligation by providing services to a customer. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by the Company from a customer, are excluded from revenue. Adoption of Financial Accounting Standards Board Accounting Standards Update (“ASU”) No. 2014-09 Topic 606, Revenue from Contracts with Customers (“Topic 606”) On January 1, 2018, the date of initial application, the Company adopted Topic 606 using the modified retrospective method by recognizing the cumulative effect of initially applying Topic 606 as an adjustment to the opening balance of retained earnings, resulting in an increase of $454 , primarily due to new contract acquisition costs. The initial application scopes in those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning January 1, 2018 are presented under Topic 606. The prior period consolidated financial statement have not been retrospectively adjusted and continue to be reported under the accounting standards in effect for those periods. The key area impacted upon adoption of Topic 606 relates to the accounting for sales commissions costs. Specifically, under Topic 606 a portion of sales commission costs have been recorded as an asset and recognized as an operating expense on a straight-line basis over the expected period of benefit. Prior to adoption, the Company was expensing sales commission costs as incurred. Nature of services The Company derives its revenues from operations management and analytics services. The Company operates in the business process management (“BPM”) industry providing operations management and analytics services helping businesses enhance revenue growth and improve profitability. The Company provides BPM or “operations management” services, which typically involve transfer to the Company of business operations of a client, after which it administers and manages those operations for its client on an ongoing basis. The Company also provides industry-specific digital transformational services related to operations management services, and analytics services that focus on driving improved business outcomes for clients by generating data-driven insights across all parts of their business. The Company also provides care optimization and reimbursement optimization services, for its clients through its healthcare analytics solutions and services. The Company offers integrated solutions to help its clients with cost containment by leveraging technology platforms, customizable and configurable analytics and expertise in healthcare reimbursements to help clients enhance their claims payment accuracy. Arrangements with Multiple Performance Obligations The Company’s contracts with customers do not generally bundle different services together except for software and related services contracts, which are not significant, involving implementation services and post contract maintenance services. In such software and related services contracts, revenue is allocated to each performance obligation based on the relative standalone selling price. A separate contract is generally drafted for each type of service sold, even if to the same customer. The typical length of a contract is 3 to 5 years for our operations management contracts. Type of Contracts i. a) Revenues under time-and-material, transaction and outcome-based contracts are recognized as the services are performed. When the terms of the client contract specify service level parameters that must be met (such as turnaround time or accuracy), the Company monitors such service level parameters to determine if any service credits or penalties have been incurred. Revenues are recognized net of any penalties or service credits that are due to a client. b) In respect of arrangements involving subcontracting, in part or whole of the assigned work, the Company evaluates revenues to be recognized based on guidance on “Principal versus agent considerations” in Topic 606. ii. Revenues for Company’s fixed-price contracts are recognized using the time-elapsed output method because the Company transfers control evenly during execution of its projects. Determining a measure of progress requires management to make judgments that affect the timing of revenue recognized. The Company regularly monitors its estimates for progress on completion of a project and records changes in the period in which a change in an estimate is determined. If a change in an estimate results in a projected loss on a project, such loss is recognized in the period in which it is identified. iii. Revenues from the Company's software and related services contracts, which are not significant, are primarily related to maintenance renewals or incremental license fees for additional users. Maintenance revenues are generally recognized on a straight-line basis over the annual contract term. Fees for incremental license fees without any associated services are recognized upon delivery of the related incremental license. iv. Revenues from reimbursement optimization services having contingent fee arrangements are recognized by the Company at the point in time when a performance obligation is satisfied, which is when it identifies an overpayment claim and the overpaid amount is acknowledged by its customers. In such contracts, the Company’s consideration is contingent upon the actual collections made by its customers and subsequent potential retractions from providers. Based on guidance on “variable consideration” in Topic 606, the Company uses its historical experience and projections to determine the expected recoveries from its customers and recognizes revenue based upon such expected recoveries. Any adjustment required due to change in estimates are recorded in the period in which such changes are identified. Unbilled receivables represent revenues recognized for services rendered between the last billing date and the balance sheet date. Unbilled receivables also include revenues recognized from reimbursement optimization services when the Company identifies an overpayment claim and the same is acknowledged by its customers, however not invoiced at the balance sheet date. Accordingly, amounts for services that the Company has performed and for which an invoice has not yet been issued to the customers are presented as a part of contract assets as accounts receivable. The Company recognizes billings in excess of revenues recognized as deferred revenues until revenue recognition criteria as per ASC 606 is met. Client prepayments (even if nonrefundable) are deferred and recognized over future periods as services are delivered or performed. The company also has deferred revenue attributable to certain process transition activities, with respect to its customers where such activities do not represent separate performance obligations. Revenues related to such transition activities are contract liabilities classified under “Deferred Revenue” and “Other Non-current liabilities”, based on their expected recognition, in the Company's consolidated balance sheets and subsequently recognized ratably over the period in which the related services are performed. Costs related to transition activities are contract fulfillment costs, and thereby classified under “Other Current Assets” and “Other Assets” in the consolidated balance sheets, and are recognized ratably over the estimated expected period of benefit, under Cost of Revenues in the consolidated statements of income. Other incremental and direct costs incurred for acquiring contracts, such as sales commissions are contract acquisition costs and thereby classified under “Other Current Assets” and “Other Assets” in the consolidated balance sheets. Such costs are amortized over the expected period of benefit and recorded under Selling and marketing expenses in the consolidated statements of income. Any upfront payments made to customers are contract assets and classified under “Other Current Assets and Other Assets” in the consolidated balance sheets. Such costs are amortized over the expected period of benefit and are recorded as an adjustment to transaction price and reduced from revenues. Reimbursements of out-of-pocket expenses received from clients are included as part of revenues. Reimbursements of out-of-pocket expenses included in revenues were $20,796 , $17,982 and $21,812 for the years ended December 31, 2018, 2017 and 2016, respectively. Payment terms All contracts entered into by the Company specify the payment terms and are defined for each contract separately. Usual payment terms range between 30 - 60 days. The Company does not have any extended payment terms clauses in existing contracts. At times, the Company enters into fixed price contracts and software licenses involving significant implementation wherein the milestones are defined such that the Company can recover the costs with a reasonable margin. Variable Consideration Variability in the transaction price arises primarily due to service level agreements, cost of living adjustments, and pre-payment and volume discounts. The Company considers its experience with similar transactions and expectations regarding the contract in estimating the amount of variable consideration that should be recognized during a period. The Company believes that the expected value method is most appropriate for determining the variable consideration since the company has large number of contracts with similar nature of transactions/services. Allocation of transaction price to performance obligations The transaction price is allocated to performance obligations on a relative standalone selling price basis. Standalone selling prices are estimated by reference to the total transaction price less the sum of the observable standalone selling prices of other goods or services promised in the contract. In assessing whether to allocate variable consideration to a specific part of the contract, the Company considers the nature of the variable payment and whether it relates specifically to its efforts to satisfy a specific part of the contract. Practical expedients and exemptions The Company does not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which the Company recognizes revenue at the amount to which the Company has the right to invoice for services performed.
Cash and Cash Equivalents and Restricted Cash	The Company considers all highly liquid investments purchased with an original maturity of ninety days or less to be cash equivalents. Pursuant to the Company’s investment policy, surplus funds are invested in highly-rated debt mutual funds, money market accounts and time deposits to reduce its exposure to market risk with regard to these funds. Restricted cash represents amounts on deposit with banks against bank guarantees issued through banks in favor of relevant statutory authorities for equipment imports, deposits for obtaining indirect tax registration and for demands against pending income tax assessments (refer Note 8 to the consolidated financial statements for details). These deposits with banks have maturity dates after December 31, 2019. Restricted cash presented under current assets represents funds held on behalf of clients in dedicated bank accounts. Effective January 1, 2018, the Company adopted ASU No. 2016-18, Statements of Cash Flows ("Topic 230"), Restricted Cash . Pursuant to this adoption, for purposes of the statements of cash flows, the Company includes in its cash and cash-equivalent balances those amounts that have been classified as restricted cash and restricted cash equivalents for each period presented.
Investments	The Company’s investments consist of time deposits with financial institutions which are valued at cost and approximate fair value. Interest earned on such investments is included in interest income. Investments with original maturities greater than ninety days but less than twelve months are classified as short-term investments. Investments with maturities greater than twelve months from the balance sheet date are classified as long-term investments. The Company's mutual fund investments are in debt and money market funds which invest in instruments of various maturities in India. These investments are accounted for in accordance with the fair value option under Financial Accounting Standard Board Accounting Standards Codification (“ASC”) Topic 825, Financial Instruments , (“Topic 825”) and change in fair value is included in interest and other income. The fair value is represented by original cost on the acquisition date and the net asset value (“NAV”) as quoted, at each reporting period. Gain or loss on the disposal of these investments is calculated using the weighted average cost of the investments sold or disposed and is included in interest and other income.
Accounts Receivable	Accounts receivable include unbilled accounts receivable which represent revenues on contracts to be billed, in subsequent periods, as per the terms of the related contracts. Accounts receivable are recorded net of allowances for doubtful accounts. Allowances for doubtful accounts are established through the evaluation of the accounts receivable aging and prior collection experience, current market conditions, clients’ financial condition and the amounts of receivables in dispute to ascertain the ultimate collectability of these receivables.
Property and equipment	Property and equipment are stated at cost less accumulated depreciation and impairment. Equipment held under capital leases are capitalized at the commencement of the lease at the lower of present value of minimum lease payments at the inception of the leases or its fair value. Advances paid towards acquisition of property and equipment and the cost of property and equipment not yet placed in service before the end of the reporting period are classified as capital work in progress. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Depreciation and amortization on equipment held under capital leases and leasehold improvements are computed using the straight-line method over the shorter of the asset's estimated useful lives or the lease term. The Company reviews property and equipment for impairment whenever events or changes in circumstances indicate that the related carrying amounts may not be recoverable. Useful Lives Assets: Network equipment and computers 3-5 Software 3-5 Leasehold improvements 3-8 Office furniture and equipment 3-8 Motor vehicles 2-5 Buildings 30
Software Development Costs	The Company capitalizes certain costs related to the development or enhancements to existing software products to be sold, leased or otherwise marketed and / or used for internal use. The Company begins to capitalize costs to develop or enhance software when planning stage efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and the software will be used as intended. Costs incurred prior to meeting these criteria, together with costs incurred for training and maintenance, are expensed as incurred and recorded within “general and administrative expenses” in the Company’s consolidated statements of income. The Company exercises judgment in determining the point at which various projects may be capitalized, in assessing the ongoing value of the capitalized costs, and in determining the estimated useful lives over which the costs are amortized. Annual amortization of internally developed software products is the greater of the amount computed using the ratio that current gross revenues for a product bear to the total of current and anticipated future gross revenues for that product or the straight-line method over the remaining estimated economic life of the software product, generally estimated to be up to 5 years from the date the product became available for use.
Business Combinations, Goodwill and Other Intangible Assets	ASC Topic 805, Business Combinations, requires that the acquisition method of accounting be used for all business combinations. The guidance specifies criteria as to intangible assets acquired in a business combination that must be recognized and reported separately from goodwill. Contingent consideration is recognized at its fair value on the acquisition date. A liability resulting from contingent consideration is re-measured to fair value as of each reporting date until the contingency is resolved. Changes in fair value are recognized in earnings. These fair value measurements represent Level 3 measurements as they are based on significant inputs not observable in the market. Under ASC 350 all assets and liabilities of the acquired businesses, including goodwill, are assigned to reporting units. Acquisition related costs are expensed as incurred under general and administrative expenses. Goodwill represents the cost of the acquired businesses in excess of the fair value of identifiable tangible and intangible net assets purchased in a business combination. Goodwill is not amortized but is tested for impairment at least on an annual basis, relying on a number of factors including operating results, business plans and estimated future cash flows of the reporting units to which it is assigned. The Company undertakes studies to determine the fair values of assets and liabilities acquired and allocate purchase consideration to assets and liabilities, including property and equipment, goodwill and other identifiable intangibles. The Company examines the carrying value of the goodwill annually in the fourth quarter, or more frequently, as circumstances warrant, to determine whether there are any impairment losses. The Company tests for goodwill impairment at the reporting unit level, as that term is defined in US GAAP. Refer to Note 10 for discussion of the Company's goodwill impairment testing. As stated in Note 2(x), we adopted ASU No. 2017-04, Simplifying the Test for Goodwill Impairment, during 2018 in conjunction with our goodwill impairment assessment. The quantitative goodwill impairment test involves a comparison of the fair value of a reporting unit with its carrying amount. The fair value of the reporting unit is measured using the income approach. Under the income approach, fair value is determined based on the present value of estimated future cash flows, discounted at an appropriate risk-adjusted rate. The Company uses its internal forecasts to estimate future cash flows and include an estimate of long-term future growth rates based on its most recent views of the long-term outlook for each business. Actual results may differ from those assumed in our forecasts. Discount rate assumptions are based on an assessment of the risk inherent in the future cash flows of the respective reporting units. The discount rate is mainly based on judgment of the specific risk inherent within each reporting unit. The variables within the discount rate, many of which are outside of the Company’s control, provide the Company’s best estimate of all assumptions applied within the DCF model. Determining fair value requires the exercise of significant judgment, including assumptions about appropriate discount rates, perpetual growth rates and the amount and timing of expected future cash flows. There can be no assurance that operations will achieve the future cash flows reflected in the projections. If the carrying amount of the reporting unit exceeds its fair value, an impairment loss shall be recognized, if any, in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. Goodwill of a reporting unit is tested for impairment annually or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit below its carrying amount. Intangible assets acquired in a business combination are initially valued and recognized at fair market value using generally accepted valuation methods appropriate for the type of intangible asset. Intangible assets with definite lives are amortized over the estimated useful lives and are reviewed for impairment, if indicators of impairment arise. The evaluation of impairment is based upon a comparison of the carrying amount of the intangible asset to its fair value, which is calculated using the estimated future undiscounted net cash flows expected to be generated by the asset. If the fair value of the intangible assets is less than the carrying amount of the asset, the asset is considered impaired and an impairment expense is recognized equal to any shortfall in the current period. The Company’s definite lived intangible assets are amortized over their estimated useful lives as listed below using a straight-line method: Customer relationships 3-15 years Leasehold benefits 3-8 years Developed technology 5-10 years Non-compete agreements 1-5 years Trade names and trademarks 3-10 years
Investment in Equity Affiliate	Investments in equity affiliate are initially recorded at cost and any excess cost over proportionate share of the fair value of the net assets of the investee at the acquisition date is recognized as goodwill. The proportionate share of net income or loss of the investee is recognized in the consolidated statements of income. The Company periodically reviews the carrying value of its investment to determine if there has been any other than temporary decline in carrying value. The investment balance for an investee is increased or decreased for cash contribution and distributions to or from, respectively.
Impairment of Long-lived Assets	Long-lived assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Such assets are required to be tested for impairment if the carrying amount of the assets is higher than the future undiscounted net cash flows expected to be generated from the assets. Determining whether an impairment has occurred typically requires various estimates and assumptions, including determining which undiscounted cash flows are directly related to the potentially impaired asset, the useful life over which cash flows will occur, their amount, and the asset’s residual value, if any. In turn, measurement of an impairment loss requires a determination of fair value, which is based on the best information available. The Company derives the required undiscounted cash flow estimates from its historical experience and its internal business plans. To determine fair value, the Company uses its internal cash flow estimates discounted at an appropriate discount rate and independent appraisals, as appropriate. The impairment amount to be recognized is measured as the amount by which the carrying value of the assets exceeds their fair value. The Company determines fair value by using a discounted cash flow approach.
Derivative Financial Instruments	In the normal course of business, the Company uses derivative instruments for the purpose of mitigating the exposure from foreign currency fluctuation risks associated with forecasted transactions denominated in certain foreign currencies and to minimize earnings and cash flow volatility associated with changes in foreign currency exchange rates, and not for speculative trading purposes. These derivative contracts are purchased within the Company’s policy and are with counterparties that are highly rated financial institutions. The Company hedges forecasted transactions that are subject to foreign exchange exposure with foreign currency exchange contracts that qualify as cash flow hedges. Changes in the fair value of these cash flow hedges are recorded as a component of accumulated other comprehensive income/(loss), net of tax, until the hedged transactions occurs. The Company early adopted ASU No. 2017-12, Derivative and Hedging ("Topic 815"), Targeted Improvements to Accounting for Hedging Activities. Pursuant to this adoption, effective January 1, 2017, the resultant foreign exchange gain/(loss) upon settlement of cash flow hedges are recorded in the consolidated statements of income along with the underlying hedged item in the same line as either part of “Cost of revenue”, “General and administrative expenses”, “Selling and marketing expenses”, “Depreciation and amortization”, as applicable. Prior to January 1, 2017, the resultant foreign exchange gain/(loss) on settlement of cash flow hedges and changes in the fair value of cash flow hedges deemed ineffective have been recorded in “Foreign exchange gain, net” in the consolidated statements of income. The Company also uses derivatives instruments consisting of foreign currency exchange contracts to economically hedge intercompany balances and other monetary assets or liabilities denominated in currencies other than the functional currency. Changes in the fair value of these derivatives are recognized in the consolidated statements of income and are included in foreign exchange gain/(loss). The Company evaluates hedge effectiveness of cash flow hedges at the time a contract is entered into as well as on an ongoing basis. For hedge relationships that are discontinued because the forecasted transaction is not expected to occur by the end of the originally specified period, any related derivative amounts recorded in equity are reclassified to earnings.
Borrowings	The Company accounts for convertible notes in accordance with the guidelines established by the ASC 470-20, Debt with Conversion and Other Options. The Company separates the Notes into liability and equity components. The Beneficial Conversion Feature ("BCF") of a convertible note, which is the equity component and recorded as additional paid-in capital, is normally characterized as the convertible portion or feature of certain notes payable that provide a rate of conversion that is below market value or in-the-money when issued. The Company records a BCF related to the issuance of a convertible note when issued. If a convertible note is within the scope of the Cash Conversion Subsections and contains embedded features other than the embedded conversion option, the guidance in ASC 815-15, Derivatives and Hedging - Embedded Derivatives (ASC 815-15), is applied to determine if any of those features must be separately accounted for as a derivative instrument. The estimated fair value of the liability component at issuance is determined using a discounted cash flow technique, which considers debt issuances with similar features of the Company’s convertible notes, excluding the conversion feature. The excess of the gross proceeds received over the estimated fair value of the liability component is allocated to the BCF, which is credited to additional paid-in-capital, with a corresponding offset recognized as a discount to reduce the net carrying value of the convertible notes. The discount is amortized to interest expense over the expected term of the convertible notes using the effective interest method.
Employee Benefits	Employee Benefits Contributions to defined contribution plans are charged to the consolidated statements of income in the period in which services are rendered by the covered employees. Current service costs for defined benefit plans are accrued in the period to which they relate. The liability in respect of defined benefit plans is calculated annually by the Company using the projected unit credit method. Prior service cost, if any, resulting from an amendment to a plan is recognized and amortized over the remaining period of service of the covered employees. The Company recognizes its liabilities for compensated absences depending on whether the obligation is attributable to employee services already rendered, relates to rights that vest or accumulate and payment is probable and estimable. Effective January 1, 2018, the Company adopted ASU No. 2017-07, Compensation - Retirement Benefits ("Topic 715"), Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post Retirement Benefit Cost. Pursuant to this, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the 2017 and 2016 consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The interest cost, expected return on plan assets and amortization of actuarial gains/loss, have been reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. Refer to Note 21 and Note 27 to the consolidated financial statements for details.
Stock-Based Compensation	The Company recognizes stock-based compensation expense in the consolidated financial statements for awards of equity instruments to employees and non-employee directors based on the grant-date fair value of those awards. The Company recognizes these compensation costs over the requisite service period of the award. Forfeitures are accounted when the actual forfeitures occur. Under the Company’s 2018 Omnibus Incentive Plan (the “2018 Plan”), which was adopted by the Company's stockholders on June 15, 2018, which replaces and supersedes the 2015 Amendment and Restatement of the Company’s 2006 Omnibus Award Plan (the “ Prior Plan”) and is effective upon the date approved by the Company’s stockholders, the Company grants performance-based restricted stock units (“PRSUs”) to executive officers and other specified employees. 50% of the PRSUs cliff vest based on a revenue target (“PU”) at the end of a three -year period. The remaining 50% vest based on a market condition (“MUs”) that is contingent on meeting or exceeding the Company's total shareholder return relative to a group of peer companies specified under the program, measured over a three -year performance period. The award recipient may earn up to two hundred percent ( 200% ) of the PRSUs granted based on the actual achievement of both targets. The fair value of each PU was determined based on the market price of one common share of the Company on the day prior to the date of grant, and the associated compensation expense was calculated on the basis that performance targets to receive 100% of the PUs are probable of being achieved. The compensation expense for the PUs is recognized on a straight-line basis over the service period, which is through the end of the third year. Over this period, the number of shares that will be issued will be adjusted upward or downward based upon the probability of achievement of the performance targets. The ultimate number of shares issued and the related compensation cost recognized as an expense will be based on a comparison of the final performance metrics to the specified targets. The expense related to the unvested PUs as of December 31, 2018 was based on the Company's assessment of performance criteria for these grants that would most likely be met during the respective years of vesting against the targeted performance level. The grant date fair value for the MUs was determined using a Monte Carlo simulation model and the related compensation expense is expensed on a straight-line basis over the vesting period. All compensation expense related to the MUs will be recognized if the requisite performance period is fulfilled, even if the market condition is not achieved. In March 2016, FASB issued ASU No. 2016-09, Compensation - Stock Compensation ("Topic 718"). ASU No. 2016-09 identifies areas for simplification involving several aspects of accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, an option to recognize gross stock compensation expense with actual forfeitures recognized as they occur, as well as certain classifications on the Statements of Cash Flows. The amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. The Company adopted this ASU effective January 1, 2017. The following summarizes the effects of the adoption on the Company's consolidated financial statements: Income taxes - Upon adoption of this standard, all excess tax benefits and tax deficiencies are recognized as income tax expense or benefit in the consolidated statements of income. The tax effects of exercised or vested awards are treated as discrete items in the reporting period in which they occur. The Company also recognizes excess tax benefits regardless of whether the benefit reduces taxes payable in the current period. As a result, the Company recognized discrete adjustments to income tax expense for the years ended December 31, 2018 and 2017 in the amounts of $7,227 and $9,797 , respectively, related to excess tax benefits. No adjustment is recorded for any windfall benefits previously recorded in Additional Paid-In Capital. Forfeitures - Prior to adoption, stock-based compensation expense was recognized on a straight line basis, net of estimated forfeitures, such that expense was recognized only for stock-based awards that are expected to vest. A forfeiture rate was estimated annually and revised, if necessary, in subsequent periods if actual forfeitures differed from initial estimates. Upon adoption, the Company will no longer apply a forfeiture rate and instead will account for forfeitures as they occur. The Company has applied the modified retrospective adoption approach as of January 1, 2017 and has recognized a cumulative-effect adjustment to reduce additional paid-in-capital of $5,999 and retained earnings of $4,546 (net of deferred tax effect of $1,453 ). Statements of Cash Flows - The Company historically accounted for excess tax benefits on the statements of cash flows as a financing activity. Upon adoption of this standard, excess tax benefits are classified along with other income tax cash flows as an operating activity. The Company has elected to adopt this portion of the standard on a prospective basis beginning in 2017 and accordingly prior periods have not been adjusted. Earnings Per Share - The Company uses the treasury stock method to compute diluted earnings per share, unless the effect would be anti-dilutive. The Company excluded the excess tax benefits from the assumed proceeds available to repurchase shares in the computation of diluted earnings per share. Effective January 1, 2018, the Company adopted ASU No. 2017-09, Scope of Modification Accounting . Pursuant to this, the Company applied modification accounting upon changes to the terms or conditions of share-based payment awards. Modification accounting is required only if the fair value, the vesting conditions, or the classification of the award changes as a result of the change in terms or conditions. The adoption does not have any material effect on the Company’s consolidated financial statements.
Income Taxes	The Company accounts for income taxes using the asset and liability method of accounting for income taxes. The Company calculates and provides for income taxes in each of the tax jurisdictions in which it operates. The deferred tax assets and liabilities are recognized for future tax consequences attributable to temporary differences between the financial statement carrying values of existing assets and liabilities and their respective tax bases and all operating losses carried forward, if any. Deferred tax assets and liabilities are measured using tax rates expected to apply to taxable income in the years in which the applicable temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates or tax status is recognized in the statements of income in the period in which the change is identified. Deferred tax assets are reduced by a valuation allowance if, based on available evidence, it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company establishes provisions for uncertain tax provisions and related interest and penalties when the Company believes those tax positions are not more likely than not of being sustained, if challenged.
Financial Instruments and Concentration of Credit Risk	Financial Instruments. For certain financial instruments, including cash and cash equivalents, short-term investments, accounts receivable, accounts payable, accrued expenses, and other current liabilities, recorded amounts approximate fair value due to the relatively short maturity periods of such instruments. Concentration of Credit Risk . Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, time deposits, mutual fund investments, accounts receivable and derivative financial instruments. By their nature, all such financial instruments involve risks including the credit risks of non-performance by counterparties. Pursuant to the Company’s investment policy, its surplus funds are maintained as cash or cash equivalents and are invested in highly-rated mutual funds, money market accounts and time deposits, placed with highly rated financial institutions to reduce its exposure to market risk with regard to these funds. The Company’s exposure to credit risk on account receivable is influenced mainly by the individual characteristic of each customer and the concentration of risk from the top few customer s. To mitigate this risk the Company evaluates the creditworthiness of its clients in conjunction with its revenue recognition processes as well as through its ongoing collectability assessment processes for accounts receivable. The Company does not enter into or trade financial instruments, including derivative financial instruments, for speculative purposes.
Lease Obligations	Leases under which the Company assumes substantially all risks and rewards of the ownership are classified as capital lease. When acquired, such assets are capitalized at fair value or present value of minimum committed lease payments at the inception of the lease, whichever is lower. The Company leases its office facilities under non-cancellable operating lease agreements. Office facilities subject to an operating lease and the related lease payments are not recorded on the Company’s balance sheet. Lease payments under operating lease are recognized as an expense on a straight line basis in the consolidated statements of income over the lease term.
Government Grants	Government grants related to income are recognized as a reduction of expenses in the consolidated statements of income when there is a reasonable assurance that the entity will comply with the conditions attached to the grant and that the grants will be received.
Earnings per share	Basic earnings per share is computed using the weighted average number of common shares outstanding during the period. Diluted earnings per share is computed using the weighted average number of common and dilutive common equivalent shares outstanding during the period. For the purposes of calculating diluted earnings per share, the treasury stock method is used for stock-based awards except where the results would be anti-dilutive.
Commitments and contingencies	Liabilities for loss contingencies arising from claims, assessments, litigation, fines and penalties, and other sources are recorded when it is probable that a liability has been incurred and the amount of the assessment and/or remediation can be reasonably estimated. Legal costs incurred in connection with such liabilities are expensed as incurred.
Recent Accounting Pronouncements	In February 2016, FASB issued ASU No. 2016-02, Leases ("Topic 842"), which requires the identification of arrangements that should be accounted for as leases. In general, lease arrangements exceeding a twelve month term should be recognized as assets with corresponding liabilities on the balance sheet of the lessee. Most prominent among the changes in the ASU is the recognition of right-of-use (“ROU”) assets and lease liabilities by lessees for those leases classified as operating leases under current U.S. GAAP, while accounting for finance leases remains substantially unchanged. Under the ASU, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. We will be required to recognize and measure leases existing at, or entered into after, the beginning of the earliest comparative period presented using a modified retrospective approach, with certain practical expedients available. The ASU will have a material impact on our consolidated balance sheets, but will not have a material impact on our consolidated statements of income and consolidated statements of cash flows. The new guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. In July 2018, FASB issued ASU No. 2018-11, Leases ("Topic 842"), which provide entities with an additional (and optional) transition method to adopt the new leasing standard. Under this new transition method, an entity initially applies the new leasing standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, an entity’s reporting for the comparative periods presented in the financial statements in which it adopts the new leasing standard will continue to be in accordance with current GAAP (Topic 840, Leases ). The Company is availing the relief provided in the ASU by changing the date of initial application to the beginning of the period of adoption and has also elected not to recast its comparative periods presented in the financial statements in which it adopts the new leasing standard and will continue to be in accordance with current GAAP (Topic 840, Leases ). The new guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Adoption of the ASU will result in the recognition of additional ROU assets and lease liabilities for operating leases of approximately $81,000 and $90,000 , respectively as of January 1, 2019. In June 2016, FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses , which requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is to be deducted from the amortized cost of the financial asset(s) so as to present the net carrying value at the amount expected to be collected on the financial asset. The new guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The amendment should be applied through a modified retrospective approach. Early adoption as of the fiscal years beginning after December 15, 2018 is permitted. The Company is currently evaluating the impact that the adoption of this guidance will have on its consolidated financial statements. In June 2018, FASB issued ASU No. 2018-07, Compensation-Stock Compensation ("Topic 718"): Improvements to Non-employee Share-Based Payment Accounting. This ASU involves several aspects of the accounting for non-employee share-based payment transactions resulting from expanding the scope of Topic 718, Compensation-Stock Compensation, to include share-based payment transactions for acquiring goods and services from non-employees. The amendments in this ASU affect all entities that enter into share-based payment transactions for acquiring goods and services from non-employees. This ASU is effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The adoption of this ASU is not expected to have any material effect on the Company’s consolidated financial statements. In August 2018, FASB issued ASU No. 2018-13, Fair Value Measurement ("Topic 820"): Changes to the Disclosure Requirements for Fair Value Measurement. The amendments in this ASU modify the disclosure requirements on fair value measurements in Topic 820, based on the concepts in the Concepts Statement, including the consideration of costs and benefits. The amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. An entity is permitted to early adopt either the entire standard or only the provisions that eliminate or modify requirements. The adoption of this ASU is not expected to have any material effect on the Company’s consolidated financial statements. In August 2018, FASB issued ASU No. 2018-14, Compensation-Retirement Benefits-Defined Benefit Plans-General ("Subtopic 715-20"): Changes to the Disclosure Requirements for Defined Benefit Plans. The amendments in this Update remove disclosures that no longer are considered cost beneficial, clarify the specific requirements of disclosures, and add disclosure requirements identified as relevant. The amendments in this ASU are effective for fiscal years beginning after December 15, 2020. An entity is permitted to early adopt this Update. The adoption of this ASU is not expected to have any material effect on the Company’s consolidated financial statements. In August 2018, FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software ("ASC Subtopic 350-40"): This ASU aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). Accordingly, the ASU requires an entity (customer) in a hosting arrangement that is a service contract to follow the guidance in ASC Subtopic 350-40 on internal-use software to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. The ASU No. 2018-15 also provides guidance on amortization and impairment of any costs capitalized, along with new presentation and disclosure requirements. The new guidance is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted and both prospective and retrospective transition methods are allowed. The Company is currently evaluating the impact that the adoption of this guidance will have on its consolidated financial statements. In October 2018, FASB issued ASU No. 2018-17, Consolidation ("ASC 810") - Targeted Improvements to Related Party Guidance for Variable Interest Entities : This ASU aligns the requirements for i ndirect interests held through related parties in common control arrangements should be considered on a proportional basis for determining whether fees paid to decision makers and service providers are variable interests. Accordingly, t he amendments in this ASU for determining whether a decision-making fee is a variable interest require reporting entities to consider indirect interests held through related parties under common control on a proportional basis rather than as the equivalent of a direct interest in its entirety (as currently required in GAAP).The new guidance is effective for fiscal years beginning after December 15, 2019. Early adoption is permitted and the amendment should be applied through a retrospective approach. The Company is currently evaluating the impact that the adoption of this guidance will have on its consolidated financial statements. (x) Recently Adopted Accounting Pronouncements In May 2014, FASB issued ASU No. 2014-09 ("Topic 606"), Revenue from Contracts with Customers . Topic 606 supersedes the revenue recognition requirements in ASC No. 605, Revenue Recognition ("Topic 605"), and requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The Company adopted Topic 606 as of January 1, 2018 using the modified retrospective transition method. Refer to Note 5 to the consolidated financial statements for details. In August 2016, FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments . The amendments apply to all entities that are required to present a statements of cash flows under Topic 230. The amendments are an improvement to US GAAP because they provide guidance for each of the eight issues, thereby reducing the current and potential future diversity in practice. The amendments are effective for fiscal years beginning after December 15, 2017 and interim periods within those annual periods and should be applied using a retrospective transition method to each period presented. The Company has adopted the guidance retrospectively to each period presented. The adoption does not have any material effect on the presentation of its consolidated statements of cash flows. In November 2016, FASB issued ASU No. 2016-18, Statements of cash flows ("Topic 230") - Restricted cash. The amendments apply to all entities that have restricted cash or restricted cash equivalents and are required to present a statement of cash flows under Topic 230. The amendments in this update require that a statements of cash flows should explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. The amendments are effective for fiscal years beginning after December 15, 2017 and interim periods within those annual periods and should be applied using a retrospective transition method to each period presented. Early adoption is permitted with an adjustment reflected as of the beginning of the fiscal year in which the amendment is adopted. The Company has adopted the guidance retrospectively to each period presented. Refer to Note 8 and Note 27 to the consolidated financial statements for details. In January 2017, FASB issued ASU No. 2017-04, Intangibles-Goodwill and Other ("Topic 350") - Simplifying the Test for Goodwill Impairment, which eliminates Step 2 from the goodwill impairment test. A goodwill impairment will now be the amount by which a reporting unit's carrying value exceeds its fair value, however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The ASU is effective for annual and interim periods in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed after January 1, 2017 and should be applied prospectively. Effective January 1, 2018, the Company has adopted the guidance prospectively. The adoption does not have any material effect on its consolidated financial statements. In March, 2017, FASB issued ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost . The ASU amends ASC No. 715, Compensation - Retirement Benefits , to require employers that present a measure of operating income in their statements of income to include only the service cost component of net periodic pension cost and net periodic post-retirement benefit cost in operating expenses (together with other employee compensation costs). The other components of net benefit cost, including amortization of prior service cost/credit, and settlement and curtailment effects, are to be included in non-operating expenses. The update also stipulates that only the service cost component of net benefit cost is eligible for capitalization. The amendments are effective for fiscal years beginning after December 15, 2017 and interim periods within those annual periods and should be applied using a retrospective transition method to each period presented. The Company has adopted the guidance retrospectively to each period presented. Refer to Note 21 and Note 27 to the consolidated financial statements for details. In May 2017, FASB issued ASU No. 2017-09, Compensation - Stock Compensation ("Topic 718"): Scope of Modification Accounting . This ASU provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting. Modification accounting is required only if the fair value, the vesting conditions, or the classification of the award changes as a result of the change in terms or conditions. The amendments in this ASU are effective for all entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period, for public business entities for reporting periods for which financial statements have not yet been issued. The amendments in this ASU should be applied prospectively to an award modified on or after the adoption date. The Company has adopted the guidance effective January 1, 2018. The adoption does not have any material effect on its consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of Property and Equipment, Estimated Useful Lives	Useful Lives Assets: Network equipment and computers 3-5 Software 3-5 Leasehold improvements 3-8 Office furniture and equipment 3-8 Motor vehicles 2-5 Buildings 30 Internally developed software costs, included under Software, was as follows: As of December 31, 2018 December 31, 2017 Cost $ 8,783 $ 2,571 Less : Accumulated amortization (2,393 ) (976 ) $ 6,390 $ 1,595 The depreciation and amortization expense excluding amortization of acquisition-related intangibles recognized in the consolidated statements of income was as follows: Year ended December 31, 2018 2017 2016 Depreciation and amortization expense $ 28,189 $ 24,574 $ 22,707 The amortization expense on internally developed software recognized in the consolidated statements of income was as follows: Year ended December 31, 2018 2017 2016 Amortization expense $ 1,417 $ 640 $ 336 Property and equipment, net consist of the following: As of Estimated useful lives (Years) December 31, 2018 December 31, 2017 Owned Assets: Network equipment and computers 3-5 $ 85,921 $ 77,587 Software 3-5 69,752 59,325 Leasehold improvements 3-8 39,533 38,857 Office furniture and equipment 3-8 20,097 19,667 Motor vehicles 2-5 635 638 Buildings 30 1,140 1,245 Land — 746 815 Capital work in progress — 11,026 9,184 228,850 207,318 Less: Accumulated depreciation and amortization (155,798 ) (141,059 ) $ 73,052 $ 66,259 Assets under capital leases: Leasehold improvements $ 778 $ 941 Office furniture and equipment 53 167 Motor vehicles 628 710 1,459 1,818 Less: Accumulated depreciation and amortization (1,001 ) (1,320 ) $ 458 $ 498 Property and equipment, net $ 73,510 $ 66,757
Summary of Lived Intangible Assets Amortized over their Estimated Useful Lives	The Company’s definite lived intangible assets are amortized over their estimated useful lives as listed below using a straight-line method: Customer relationships 3-15 years Leasehold benefits 3-8 years Developed technology 5-10 years Non-compete agreements 1-5 years Trade names and trademarks 3-10 years

Segment & Geographical Inform_2

Segment & Geographical Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Revenues and Cost of Revenues for Company's Reportable Segments	Revenues and cost of revenues for each of the years ended December 31, 2018, 2017 and 2016, for each of the reportable segments, are as follows: Year ended December 31, 2018 Insurance Healthcare TT&L F&A All Other Analytics Total Revenues, net $ 258,144 $ 84,391 $ 70,237 $ 97,941 $ 87,109 $ 285,290 $ 883,112 Cost of revenues (1) 174,921 66,768 41,066 59,155 58,341 184,604 584,855 Gross profit (1) $ 83,223 $ 17,623 $ 29,171 $ 38,786 $ 28,768 $ 100,686 $ 298,257 Operating expenses 248,436 Foreign exchange gain, interest expense and other income, net 10,549 Income tax expense 3,397 Loss from equity-method investment 247 Net income $ 56,726 Year ended December 31, 2017 Insurance Healthcare TT&L F&A All Other Analytics Total Revenues, net $ 234,794 $ 77,013 $ 70,951 $ 86,527 $ 83,082 $ 209,943 $ 762,310 Cost of revenues (1)(2)(3) 159,433 49,412 41,337 51,362 56,638 136,960 495,142 Gross profit (1)(2)(3) $ 75,361 $ 27,601 $ 29,614 $ 35,165 $ 26,444 $ 72,983 $ 267,168 Operating expenses (2)(3) 194,443 Foreign exchange gain, interest expense and other income, net (2)(3) 12,309 Income tax expense 36,146 Net income $ 48,888 Year ended December 31, 2016 Insurance Healthcare TT&L F&A All Other Analytics Total Revenues, net $ 206,327 $ 68,656 $ 69,366 $ 79,416 $ 96,489 $ 165,734 $ 685,988 Cost of revenues (1)(3) 146,151 44,060 41,923 48,258 61,019 106,307 447,718 Gross profit (1)(3) $ 60,176 $ 24,596 $ 27,443 $ 31,158 $ 35,470 $ 59,427 $ 238,270 Operating expenses (3) 173,775 Foreign exchange gain, interest expense and other income, net (3) 19,389 Income tax expense 22,151 Net income $ 61,733 (1) Exclusive of depreciation and amortization. (2) The Company early adopted ASU No. 2017-12, Derivative and Hedging ("Topic 815"), Targeted Improvements to Accounting for Hedging Activities . Pursuant to this adoption, effective January 1, 2017, the resultant foreign exchange gain/(loss) upon settlement of cash flow hedges are recorded along with the underlying hedged item in the same line as either part of “Cost of revenues”, “General and administrative expenses”, “Selling and marketing expenses”, and "Depreciation and amortization”, as applicable. Refer to Note 18 to the consolidated financial statements for details. (3) Effective January 1, 2018, the Company adopted ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost . Pursuant to this, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the 2017 and 2016 consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The interest cost, expected return on plan assets and amortization of actuarial (gain)/loss, have been reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. Refer to Note 21 and Note 27 to the consolidated financial statements for details. Revenues, net of the Company by service type, were as follows: Year ended December 31, 2018 2017 2016 BPM and related services (1) $ 597,822 $ 552,367 $ 520,254 Analytics services 285,290 209,943 165,734 Total $ 883,112 $ 762,310 $ 685,988 (1) BPM and related services include revenues of the Company's five industry-focused operating segments, one capability operating segment and the consulting operating segment, which provides services related to operations management services.
Revenues Based on Geographical Information	The Company attributes the revenues to regions based upon the location of its customers. Year ended December 31, 2018 2017 2016 Revenues, net United States $ 732,589 $ 626,336 $ 554,945 Non-United States United Kingdom 114,515 108,640 109,905 Rest of World 36,008 27,334 21,138 Total Non-United States $ 150,523 $ 135,974 $ 131,043 $ 883,112 $ 762,310 $ 685,988
Property and Equipment, Net Based on Geographical Information	Property and equipment, net by geographic area, were as follows: As of December 31, 2018 December 31, 2017 Property and equipment, net India $ 36,152 $ 39,143 United States 28,254 16,371 Philippines 5,985 8,217 Rest of World 3,119 3,026 $ 73,510 $ 66,757

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results	Summarized quarterly results for the years ended December 31, 2018 and 2017 are as follows: Three months ended 2018 Year ended March 31 June 30 September 30 December 31 December 31, 2018 Revenues, net $ 206,973 $ 210,112 $ 231,124 $ 234,903 $ 883,112 Gross profit (1) $ 68,872 $ 70,463 $ 78,967 $ 79,955 $ 298,257 Net income $ 23,158 $ 14,462 $ 15,249 $ 3,857 $ 56,726 Earnings per share: Basic $ 0.67 $ 0.42 $ 0.44 $ 0.11 $ 1.65 Diluted $ 0.66 $ 0.41 $ 0.43 $ 0.11 $ 1.62 Weighted-average number of shares used in computing earnings per share: Basic 34,446,265 34,511,777 34,458,520 34,388,025 34,451,008 Diluted 35,302,926 35,142,388 35,207,991 34,921,388 35,030,984 Stock compensation expense $ 5,074 $ 6,893 $ 5,344 $ 6,590 $ 23,901 Amortization of intangibles $ 3,947 $ 3,761 $ 6,718 $ 5,951 $ 20,377 Three months ended 2017 Year ended March 31 June 30 September 30 December 31 December 31, 2017 Revenues, net $ 183,033 $ 189,057 $ 192,345 $ 197,875 $ 762,310 Gross profit (1)(2)(3) $ 63,961 $ 65,323 $ 69,268 $ 68,616 $ 267,168 Net income/(loss) $ 16,788 $ 20,378 $ 21,077 $ (9,355 ) $ 48,888 Earnings/(loss) per share: Basic (4) $ 0.50 $ 0.60 $ 0.62 $ (0.27 ) $ 1.44 Diluted (4) $ 0.48 $ 0.58 $ 0.60 $ (0.27 ) $ 1.39 Weighted-average number of shares used in computing earnings per share: Basic (4) 33,845,560 33,819,320 33,838,374 34,086,711 33,897,916 Diluted (4) 35,108,882 34,993,226 35,043,987 34,086,711 35,110,210 Stock compensation expense $ 5,956 $ 5,107 $ 5,708 $ 6,270 $ 23,041 Amortization of intangibles $ 3,498 $ 3,507 $ 3,487 $ 3,483 $ 13,975 (1) Exclusive of depreciation and amortization. (2) During the quarter ended December 31, 2017, the Company early adopted ASU No. 2017-12, Derivative and Hedging ("Topic 815"), Targeted Improvements to Accounting for Hedging Activities . Pursuant to this adoption effective January 1, 2017, the Company recorded settlement gain/(loss) on cash flow hedges in cost of revenues and operating expenses, as applicable, in the consolidated statements of income for each of the quarters of 2017. Refer Note 18 for further details. (3) Effective January 1, 2018, the Company adopted ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost . Pursuant to this, the Company retrospectively included only the service cost component of the net periodic benefit cost in the same line item or items on the 2017 and 2016 consolidated statements of income as other compensation costs arising from services rendered by the respective employees during the period. The interest cost, expected return on plan assets and amortization of actuarial gains/loss, have been reclassified from “Cost of revenues”, “General and administrative expenses” and “Selling and marketing expenses” to “Other income, net”. (4) Total of quarterly basic and diluted earnings per share and weighted average number of shares used in computing earnings per share will not be equal to year end basic and diluted earnings per share and weighted average number of shares used in computing earnings per share, respectively. For the quarter ended December 31, 2017, nil weighted average common shares were considered anti-dilutive and not included in computing diluted earnings per share.

Revenues, net (Tables)

Revenues, net (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract with Customer, Receivables and Liabilities	The following table provides information about accounts receivable, contract assets and contract liabilities from contracts with customers: As of December 31, 2018 December 31, 2017 Accounts receivable, net $ 164,752 $ 135,705 Contract assets $ 5,445 $ 2,643 Contract liabilities Deferred revenue (advance payments portion) $ 6,345 $ 9,311 Consideration received from customer for transitions activities $ 1,669 $ 1,601

Other Income, net (Tables)

Other Income, net (Tables)	12 Months Ended
	Dec. 31, 2018
Other Nonoperating Income (Expense) [Abstract]
Other Income, net	Other Income, net consists of the following: Year ended December 31, 2018 2017 2016 Interest and dividend income $ 1,873 $ 1,625 $ 1,673 Gain on sale and mark-to-market of mutual funds 9,970 8,766 8,087 Change in fair value of earn-out consideration — — 4,060 Others, net 1,146 968 1,315 Other income, net $ 12,989 $ 11,359 $ 15,135

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted earnings per share: Year ended December 31, 2018 2017 2016 Numerator: Net income $ 56,726 $ 48,888 $ 61,733 Denominators: Basic weighted average common shares outstanding 34,451,008 33,897,916 33,566,367 Dilutive effect of share based awards 579,976 1,212,294 996,952 Diluted weighted average common shares outstanding 35,030,984 35,110,210 34,563,319 Earnings per share attributable to ExlService Holdings, Inc. stockholders: Basic $ 1.65 $ 1.44 $ 1.84 Diluted $ 1.62 $ 1.39 $ 1.79 Weighted average potentially dilutive shares considered anti-dilutive and not included in computing diluted earnings per share 121,344 151,961 92,538

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash (Tables)	12 Months Ended
	Dec. 31, 2018
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	For the purpose of statements of cash flows, cash, cash equivalents and restricted cash comprise of the following: As of December 31, 2018 December 31, 2017 December 31, 2016 Cash and cash equivalents $ 95,881 $ 86,795 $ 213,155 Restricted cash (current) 5,608 3,674 3,846 Restricted cash (non-current) 2,642 3,808 3,393 $ 104,131 $ 94,277 $ 220,394
Restrictions on Cash and Cash Equivalents	For the purpose of statements of cash flows, cash, cash equivalents and restricted cash comprise of the following: As of December 31, 2018 December 31, 2017 December 31, 2016 Cash and cash equivalents $ 95,881 $ 86,795 $ 213,155 Restricted cash (current) 5,608 3,674 3,846 Restricted cash (non-current) 2,642 3,808 3,393 $ 104,131 $ 94,277 $ 220,394

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Useful Lives Assets: Network equipment and computers 3-5 Software 3-5 Leasehold improvements 3-8 Office furniture and equipment 3-8 Motor vehicles 2-5 Buildings 30 Internally developed software costs, included under Software, was as follows: As of December 31, 2018 December 31, 2017 Cost $ 8,783 $ 2,571 Less : Accumulated amortization (2,393 ) (976 ) $ 6,390 $ 1,595 The depreciation and amortization expense excluding amortization of acquisition-related intangibles recognized in the consolidated statements of income was as follows: Year ended December 31, 2018 2017 2016 Depreciation and amortization expense $ 28,189 $ 24,574 $ 22,707 The amortization expense on internally developed software recognized in the consolidated statements of income was as follows: Year ended December 31, 2018 2017 2016 Amortization expense $ 1,417 $ 640 $ 336 Property and equipment, net consist of the following: As of Estimated useful lives (Years) December 31, 2018 December 31, 2017 Owned Assets: Network equipment and computers 3-5 $ 85,921 $ 77,587 Software 3-5 69,752 59,325 Leasehold improvements 3-8 39,533 38,857 Office furniture and equipment 3-8 20,097 19,667 Motor vehicles 2-5 635 638 Buildings 30 1,140 1,245 Land — 746 815 Capital work in progress — 11,026 9,184 228,850 207,318 Less: Accumulated depreciation and amortization (155,798 ) (141,059 ) $ 73,052 $ 66,259 Assets under capital leases: Leasehold improvements $ 778 $ 941 Office furniture and equipment 53 167 Motor vehicles 628 710 1,459 1,818 Less: Accumulated depreciation and amortization (1,001 ) (1,320 ) $ 458 $ 498 Property and equipment, net $ 73,510 $ 66,757

Business Combinations, Goodwi_2

Business Combinations, Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations, Goodwill and Intangible Assets Disclosure [Abstract]
Allocation of Purchase Price to Assets Acquired and Liabilities Assumed	The Company finalized its purchase price allocation for the acquisition based on their fair values as set forth below: Amount Tangible Assets $ 5,475 Liabilities (5,733 ) Identifiable Intangible Assets: Customer relationships 6,760 Developed technology 1,510 Trade names and trademarks 570 Goodwill 14,229 Total purchase price $ 22,811 The Company’s preliminary purchase price allocation to net tangible and intangible assets of SCIO is as follows: Assets: Cash and cash equivalents $ 9,842 Restricted cash 2,790 Accounts receivable 19,924 Other current assets 2,076 Property and equipment 1,824 Other assets 1,751 Intangible assets Customer relationships 47,800 Developed technology 21,400 Trade names and trademarks 3,700 111,107 Liabilities: Current liabilities (12,482 ) Deferred tax liabilities, net (17,132 ) Other non-current liabilities (200 ) (29,814 ) Net assets acquired $ 81,293 Goodwill 163,751 Total purchase consideration $ 245,044
Pro Forma Financial Information	The following unaudited pro forma results of operations have been prepared using the acquisition method of accounting to give effect to the Health Integrated acquisition as though it occurred on January 1, 2016. The Company completed its acquisition of Health Integrated on December 22, 2017 and accordingly Health Integrated’s operations for the period from December 22, 2017 to December 31, 2017 are included in the Company’s consolidated statement of income. The pro forma amounts reflect certain adjustments, such as depreciation and amortization on assets acquired, interest expense related to liabilities not assumed by the Company and facility costs for certain facilities not acquired. The unaudited pro forma financial information is presented for illustrative purposes only, is based on purchase price allocation, and is not necessarily indicative of the results of operations that would have actually been reported had the acquisitions occurred on January 1, 2016, nor is it necessarily indicative of the future results of operations of the combined company. Unaudited Year ended December 31, 2017 2016 Revenues $ 801,101 $ 729,938 Net income $ 46,998 $ 58,232 Earnings per share: Basic $ 1.39 $ 1.73 Diluted $ 1.34 $ 1.68 Unaudited Year ended December 31, 2018 2017 Revenues, net $ 924,172 $ 834,158 Net income $ 55,756 $ 45,827 Earnings per share: Basic $ 1.62 $ 1.35 Diluted $ 1.59 $ 1.30
Summary of Company's Goodwill	The following table sets forth details of changes in goodwill by reportable segment of the Company: Insurance Healthcare TT&L F&A All Other Analytics Total Balance as at January 1, 2017 $ 38,110 $ 19,276 $ 12,983 $ 47,537 $ 5,326 $ 63,538 $ 186,770 Acquisitions — 15,957 — — — — 15,957 Currency translation adjustments 223 — 696 835 — — 1,754 Balance as at December 31, 2017 $ 38,333 $ 35,233 $ 13,679 $ 48,372 $ 5,326 $ 63,538 $ 204,481 Acquisitions — — — — — 163,751 163,751 Measurement period adjustments* — (1,728 ) — — — — (1,728 ) Currency translation adjustments (130 ) — (982 ) (1,179 ) — — (2,291 ) Impairment charges — (14,229 ) — — — — (14,229 ) Balance as at December 31, 2018 $ 38,203 $ 19,276 $ 12,697 $ 47,193 $ 5,326 $ 227,289 $ 349,984 * Subsequent to the date of acquisition and upon receipt of additional information, adjustments of $1,728 have been made to the Health Integrated amounts of net tangible assets acquired and the earn-out with the corresponding offset to goodwill. These adjustments are within the measurement period and would be accounted for prospectively. These adjustments did not have a significant impact on the Company’s consolidated statements of income, balance sheets or cash flows.
Schedule of Finite-Lived Intangible Assets	Information regarding the Company’s intangible assets is set forth below: As of December 31, 2018 Gross Carrying Amount Accumulated Amortization Accumulated Impairment Net Carrying Amount Finite-lived intangible assets: Customer relationships $ 129,790 $ (56,367 ) $ (5,549 ) $ 67,874 Leasehold benefits 2,644 (2,567 ) — 77 Developed technology 37,154 (14,653 ) — 22,501 Non-compete agreements 2,045 (1,937 ) — 108 Trade names and trademarks 9,639 (5,326 ) (278 ) 4,035 $ 181,272 $ (80,850 ) $ (5,827 ) $ 94,595 Indefinite-lived intangible assets: Trade names and trademarks $ 900 $ — $ — $ 900 Total intangible assets $ 182,172 $ (80,850 ) $ (5,827 ) $ 95,495 As of December 31, 2017 Gross Carrying Amount Accumulated Amortization Accumulated Impairment Net Carrying Amount Finite-lived intangible assets: Customer relationships $ 82,165 $ (43,667 ) $ — $ 38,498 Leasehold benefits 2,888 (2,596 ) — 292 Developed technology 15,835 (8,749 ) — 7,086 Non-compete agreements 2,045 (1,780 ) — 265 Trade names and trademarks 5,951 (4,034 ) — 1,917 $ 108,884 $ (60,826 ) $ — $ 48,058 Indefinite-lived intangible assets: Trade names and trademarks $ 900 $ — $ — $ 900 Total intangible assets $ 109,784 $ (60,826 ) $ — $ 48,958 The remaining weighted average life of intangible assets is as follows: (in years) Customer relationships 7.93 Leasehold benefits 0.41 Developed technology 4.34 Non-compete agreements 0.72 Trade names and trademarks (Finite lived) 3.11
Schedule of Indefinite-Lived Intangible Assets	Information regarding the Company’s intangible assets is set forth below: As of December 31, 2018 Gross Carrying Amount Accumulated Amortization Accumulated Impairment Net Carrying Amount Finite-lived intangible assets: Customer relationships $ 129,790 $ (56,367 ) $ (5,549 ) $ 67,874 Leasehold benefits 2,644 (2,567 ) — 77 Developed technology 37,154 (14,653 ) — 22,501 Non-compete agreements 2,045 (1,937 ) — 108 Trade names and trademarks 9,639 (5,326 ) (278 ) 4,035 $ 181,272 $ (80,850 ) $ (5,827 ) $ 94,595 Indefinite-lived intangible assets: Trade names and trademarks $ 900 $ — $ — $ 900 Total intangible assets $ 182,172 $ (80,850 ) $ (5,827 ) $ 95,495 As of December 31, 2017 Gross Carrying Amount Accumulated Amortization Accumulated Impairment Net Carrying Amount Finite-lived intangible assets: Customer relationships $ 82,165 $ (43,667 ) $ — $ 38,498 Leasehold benefits 2,888 (2,596 ) — 292 Developed technology 15,835 (8,749 ) — 7,086 Non-compete agreements 2,045 (1,780 ) — 265 Trade names and trademarks 5,951 (4,034 ) — 1,917 $ 108,884 $ (60,826 ) $ — $ 48,058 Indefinite-lived intangible assets: Trade names and trademarks $ 900 $ — $ — $ 900 Total intangible assets $ 109,784 $ (60,826 ) $ — $ 48,958
Amortization of Intangible Assets	The amortization expense for the year is as follows: Year ended December 31, 2018 2017 2016 Amortization expense $ 20,377 $ 13,975 $ 11,873
Estimated Future Amortization of Intangible Assets	Estimated future amortization expense related to intangible assets as of December 31, 2018 is as follows: 2019 $ 21,543 2020 14,442 2021 12,743 2022 11,331 2023 9,042 2024 and thereafter 25,494 Total $ 94,595

Other Current Assets (Tables)

Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Current Assets	Other current assets consist of the following: As of December 31, 2018 December 31, 2017 Derivative instruments $ 4,059 $ 10,938 Advances to suppliers 2,910 2,451 Receivables from statutory authorities 14,145 7,598 Contract assets 1,201 401 Deferred contract fulfillment costs 1,236 474 Others 4,689 7,720 Other current assets $ 28,240 $ 29,582

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets	Other assets consist of the following: As of December 31, 2018 December 31, 2017 Lease deposits $ 8,891 $ 8,776 Derivative instruments 1,971 7,361 Deposits with statutory authorities 6,259 6,492 Term deposits 315 6,909 Contract assets 4,244 2,242 Deferred contract fulfillment costs 2,815 2,295 Others 6,520 2,294 Other assets $ 31,015 $ 36,369

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Accounts Payable and Accrued Liabilities, Current [Abstract]
Schedule of Accrued Liabilities and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: As of December 31, 2018 December 31, 2017 Accrued expenses $ 44,711 $ 43,235 Derivative instruments 3,204 555 Client liabilities 6,933 8,982 Other current liabilities 9,321 8,594 Accrued expenses and other current liabilities $ 64,169 $ 61,366

Other Non-current liabilities (

Other Non-current liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Liabilities, Noncurrent [Abstract]
Summary of Non-Current Liabilities	Other non-current liabilities consist of the following: As of December 31, 2018 December 31, 2017 Derivative instruments $ 3,075 $ 322 Unrecognized tax benefits 804 892 Deferred rent 7,834 8,176 Retirement benefits 3,616 3,377 Deferred transition revenue 945 1,034 Others 247 2,401 Other non-current liabilities $ 16,521 $ 16,202

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The balances as of December 31, 2018 and 2017 are as follows: As of December 31, 2018 December 31, 2017 Cumulative foreign currency translation gain/(loss) $ (84,105 ) $ (58,405 ) Unrealized gain/(loss) on cash flow hedges, net of taxes of $115 and $4,918, respectively (333 ) 11,932 Retirement benefits, net of taxes of ($53) and ($74), respectively 971 763 Accumulated other comprehensive gain/(loss) $ (83,467 ) $ (45,710 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value	The following table sets forth the Company’s assets and liabilities that were accounted for at fair value as of December 31, 2018 and 2017 . As of December 31, 2018 Level 1 Level 2 Level 3 Total Assets Mutual funds* $ 142,408 $ — $ — $ 142,408 Derivative financial instruments — 6,030 — 6,030 Total $ 142,408 $ 6,030 $ — $ 148,438 Liabilities Derivative financial instruments $ — $ 6,279 $ — $ 6,279 Total $ — $ 6,279 $ — $ 6,279 As of December 31, 2017 Level 1 Level 2 Level 3 Total Assets Mutual funds* $ 162,906 $ — $ — $ 162,906 Derivative financial instruments — 18,298 — 18,298 Total $ 162,906 $ 18,298 $ — $ 181,204 Liabilities Derivative financial instruments $ — $ 877 $ — $ 877 Fair value of earn-out consideration — — 920 920 Total $ — $ 877 $ 920 $ 1,797 * Represents short-term investments carried on fair value option under ASC 825 "Financial Instruments" as of December 31, 2018 and December 31, 2017.

Derivatives and Hedge Account_2

Derivatives and Hedge Accounting (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Fair Value of Foreign Currency Exchange Contracts	The following tables set forth the fair value of the foreign currency exchange contracts and their location on the consolidated balance sheets: Derivatives designated as hedging instruments : As of Foreign currency exchange contracts December 31, 2018 December 31, 2017 Other current assets $ 4,022 $ 10,892 Other assets $ 1,971 $ 7,360 Accrued expense and other current liabilities $ 3,137 $ 481 Other non-current liabilities $ 3,075 $ 322 Derivatives not designated as hedging instruments : As of Foreign currency exchange contracts December 31, 2018 December 31, 2017 Other current assets $ 37 $ 46 Accrued expense and other current liabilities $ 67 $ 74
Summary of Effect of Foreign Currency Exchange Contracts on Consolidated Statements of Income	Derivatives designated as hedging instruments : As of Foreign currency exchange contracts December 31, 2018 December 31, 2017 Other current assets $ 4,022 $ 10,892 Other assets $ 1,971 $ 7,360 Accrued expense and other current liabilities $ 3,137 $ 481 Other non-current liabilities $ 3,075 $ 322 Derivatives not designated as hedging instruments : As of Foreign currency exchange contracts December 31, 2018 December 31, 2017 Other current assets $ 37 $ 46 Accrued expense and other current liabilities $ 67 $ 74 The following tables set forth the effect of foreign currency exchange contracts on the consolidated statements of income and accumulated other comprehensive loss for the years ended December 31, 2018 , 2017 and 2016 : Year ended December 31, Forward exchange contracts : 2018 2017 2016 (Loss)/gain recognized in AOCI Derivatives in cash flow hedging relationships $ (13,919 ) $ 19,802 $ 5,129 (Loss)/gain recognized in consolidated statements of income Derivatives not designated as hedging instruments $ (3,224 ) $ 5,056 $ 4,790 Location and amount of gain/(loss) recognized in consolidated statements of income for cash flow hedging relationships and derivatives not designated as hedging instruments Year ended December 31, 2018 2017 2016 As per consolidated statements of income Gain/(loss) on foreign currency exchange contracts As per consolidated statements of income Gain/(loss) on foreign currency exchange contracts As per consolidated statements of income Gain/(loss) on foreign currency exchange contracts Cash flow hedging relationships Location in consolidated statements of income where gain/(loss) was reclassed from AOCI Cost of revenues $ 584,855 $ 2,481 $ 495,142 $ 5,465 $ 447,718 $ — General & administrative expenses $ 116,202 $ 443 $ 102,515 $ 960 $ 88,616 $ — Selling & marketing expenses $ 63,612 $ 44 $ 53,379 $ 103 $ 50,579 $ — Depreciation & amortization $ 48,566 $ 181 $ 38,549 $ 371 $ 34,580 $ — Foreign exchange gain/(loss), net $ 4,787 $ — $ 2,839 $ — $ 5,597 $ 2,669 $ 3,149 $ 6,899 $ 2,669 Derivatives not designated as hedging instruments Location in consolidated statements of income where gain/(loss) was recognized Foreign exchange gain/(loss), net $ 4,787 $ (3,224 ) $ 2,839 $ 5,056 $ 5,597 $ 4,790 $ 4,787 $ (3,224 ) $ 2,839 $ 5,056 $ 5,597 $ 4,790

Borrowings and Credit Arrange_2

Borrowings and Credit Arrangements Borrowing and Credit Arrangements (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of principle maturities of borrowings and credit arrangements	Future principal payments/maturities for all of the Company's borrowings as of December 31, 2018 were as follows: Notes Revolver Credit Structured Payables Total 2019 $ — $ 20,000 $ 1,423 $ 21,423 2020 — 28,000 691 28,691 2021 — 28,000 — 28,000 2022 — 74,000 — 74,000 2023 — — — — Thereafter 150,000 — — 150,000 Total $ 150,000 $ 150,000 $ 2,114 $ 302,114

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Summary of Change in Projected Benefit Obligation	The following table sets forth the activity and the funded status of the Gratuity Plans and the amounts recognized in the Company’s consolidated financial statements at the end of the relevant periods: 2018 2017 Change in projected benefit obligation: Projected benefit obligation as of January 1 $ 10,305 $ 9,711 Business acquisition 326 — Service cost 1,735 1,933 Interest cost 714 645 Benefits paid (1,066 ) (1,001 ) Actuarial (gain)/loss (134 ) (1,471 ) Effect of exchange rate changes (836 ) 488 Projected benefit obligation as of December 31 $ 11,044 $ 10,305 Unfunded amount–non-current $ 3,616 $ 3,377 Unfunded amount–current 8 13 Total accrued liability $ 3,624 $ 3,390 Accumulated benefit obligation $ 7,239 $ 7,022
Components of Net Periodic Benefit Cost	Components of net periodic benefit costs: Year ended December 31, 2018 2017 2016 Service cost $ 1,735 $ 1,933 $ 1,601 Interest cost 714 645 599 Expected return on plan assets (514 ) (401 ) (416 ) Amortization of actuarial (gain)/loss (153 ) 256 90 Net periodic benefit cost $ 1,782 $ 2,433 $ 1,874
Summary of Components Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive gain/(loss), net of tax as of December 31, 2018 and 2017 are as follows: December 31, 2018 2017 2016 Net actuarial gain/(loss) $ 940 $ 697 $ (831 ) Net prior service cost (22 ) (8 ) (9 ) Deferred taxes 53 74 342 Accumulated other comprehensive gain/(loss), net of tax $ 971 $ 763 $ (498 )
Summary of Weighted Average Actuarial Assumptions	The weighted average actuarial assumptions used to determine benefit obligations and net periodic gratuity cost are: December 31, 2018 2017 2016 Discount rate 7.5 % 7.0 % 6.8 % Rate of increase in compensation levels 8.2 % 9.1 % 9.2 % Expected long term rate of return on plan assets per annum 7.3 % 8.3 % 9.0 %
Summary of Expected Benefit Payments	Expected benefit payments during the year ending December 31, 2019 $ 1,820 2020 $ 1,692 2021 $ 1,621 2022 $ 1,424 2023 $ 1,332 2024 to 2028 $ 4,577
Change in Plan Assets	Change in Plan Assets Plan assets at January 1, 2017 $ 5,640 Actual return 202 Employer contribution 1,700 Benefits paid* (1,001 ) Effect of exchange rate changes 374 Plan Assets at December 31, 2017 $ 6,915 Business acquisition 231 Actual return 779 Employer contribution 1,175 Benefits paid* (1,059 ) Effect of exchange rate changes (621 ) Plan assets at December 31, 2018 $ 7,420 * Benefits payments were substantially made through the plan assets during the year ended December 31, 2018 and December 31, 2017.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Future Minimum Lease Payments under Capital Leases	The Company finances its use of certain motor vehicles and other equipment under various lease arrangements provided by financial institutions. Future minimum lease payments under these capital leases as of December 31, 2018 are as follows: During the next twelve months ending December 31, 2019 $ 283 2020 163 2021 120 2022 58 2023 and thereafter 49 Total minimum lease payments 673 Less: amount representing interest 135 Present value of minimum lease payments 538 Less: current portion 223 Long term capital lease obligation $ 315
Future Minimum Lease Payments under Non-Cancelable Operating Lease Agreements Expiring After December 31, 2017	The Company conducts its operations using facilities leased under operating lease agreements that expire at various dates. Future minimum lease payments under such agreements expiring after December 31, 2018 are set forth below: During the next twelve months ending December 31, 2019 $ 23,431 2020 20,039 2021 16,924 2022 14,804 2023 12,859 2024 and thereafter 26,114 Future minimum lease payment $ 114,171
Schedule of Rent Expense	The Company recognizes rent expense on such leases on a straight-line basis over cancelable and non-cancelable lease period determined under ASC Topic 840, Leases : Year ended December 31, 2018 2017 2016 Rent expense $ 25,573 $ 24,015 $ 21,382
Schedule of Deferred Rent	As of December 31, 2018 December 31, 2017 Cancelable and non-cancelable operating leases $ 8,782 $ 8,959

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Summary of Components of Income Before Income Taxes	The components of income before income taxes consist of the following: Year ended December 31, 2018 2017 2016 Domestic $ (24,442 ) $ 4,626 $ 12,652 Foreign 84,812 80,408 71,232 $ 60,370 $ 85,034 $ 83,884
Summary of Income Tax Expense	The income tax expense consists of the following: Year ended December 31, 2018 2017 2016 Current provision: Domestic $ (13,249 ) $ 17,407 $ 7,107 Foreign 17,271 18,008 18,428 $ 4,022 $ 35,415 $ 25,535 Deferred provision/(benefit): Domestic $ (1,999 ) $ 2,618 $ (2,506 ) Foreign 1,374 (1,887 ) (878 ) $ (625 ) $ 731 $ (3,384 ) Income tax expense $ 3,397 $ 36,146 $ 22,151
Summary of Effective Income Tax Rate Differs from Amount Computed by Applying U.S. Federal Statutory Income Tax Rate to Income Before Income Taxes	The effective income tax rate differs from the amount computed by applying the U.S. federal statutory income tax rate to income before income taxes approximately as follows: Year ended December 31, 2018 2017 2016 Expected tax expense $ 12,678 $ 29,762 $ 29,361 Change in valuation allowance — (21 ) 22 Impact of tax holiday (5,448 ) (4,396 ) (4,027 ) Foreign tax rate differential 5,014 (2,616 ) (2,716 ) Deferred tax (benefit)/provision (3,915 ) (1,887 ) (878 ) Unrecognized tax benefits and interest (88 ) (3,905 ) 495 State taxes, net of Federal taxes 2,200 339 202 Non-deductible expenses 3,066 825 144 US Tax Reform Act impact 176 29,185 — Excess tax benefit on stock-based compensation (7,227 ) (9,797 ) — Research & Development credit (1,500 ) (844 ) (890 ) Other (1,559 ) (499 ) 438 Tax expense $ 3,397 $ 36,146 $ 22,151
Summary of Components of Deferred Tax Balances	The components of the deferred tax balances as of December 31, 2018 and 2017 are as follows: As of December 31, 2018 December 31, 2017 Deferred tax assets: Depreciation and amortization $ 3,731 $ 2,183 Stock-based compensation 8,614 7,647 Accrued employee costs and other expenses 3,596 3,673 Tax credit carry forward — 1,474 Net operating loss carry forward 1,113 2,068 Unrealized exchange loss 6,671 252 Deferred rent 2,255 2,064 Others 1,380 1,007 $ 27,360 $ 20,368 Valuation allowance (99 ) (108 ) Deferred tax assets $ 27,261 $ 20,260 Deferred tax liabilities: Unrealized exchange gain $ 115 $ 5,069 Intangible assets 19,289 4,648 Unamortized discount on convertible senior notes 4,105 — Others 5,595 1,958 Deferred tax liabilities $ 29,104 $ 11,675 Net deferred tax assets/(liabilities) $ (1,843 ) $ 8,585
Summary of Activity Related to Gross Unrecognized Tax Benefits	The following table summarizes the activity related to the unrecognized tax benefits for the years ended December 31, 2018 , 2017 and 2016 . 2018 2017 2016 Balance as of January 1 $ 824 $ 3,087 $ 2,797 Increases related to prior year tax positions — — 156 Decreases related to prior year tax positions (320 ) (2,520 ) — Increases related to current year tax positions 300 169 178 Effect of exchange rate changes — 88 (44 ) Balance as of December 31 $ 804 $ 824 $ 3,087

Stock Based Compensation (Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Costs Related to Company's Stock-Based Compensation Plan	The following costs related to the Company’s stock-based compensation plan are included in the consolidated statements of income: Year ended December 31, 2018 2017 2016 Cost of revenues $ 4,924 $ 4,600 $ 3,664 General and administrative expenses 10,371 10,363 8,372 Selling and marketing expenses 8,606 8,078 7,734 Total $ 23,901 $ 23,041 $ 19,770
Stock Based Compensation Stock Option Activity	Stock option activity under the Company’s stock-based compensation plans is shown below: Number of Weighted- Aggregate Weighted- Outstanding at December 31, 2017 259,563 $ 18.03 $ 10,985 2.76 Granted — — — — Exercised (97,088 ) 14.39 4,446 — Forfeited — — — — Outstanding at December 31, 2018 162,475 $ 20.21 $ 5,267 2.24 Vested and exercisable at December 31, 2018 162,475 $ 20.21 $ 5,267 2.24
Company's Stock Options Outstanding and Stock Options Vested and Exercisable	The following table summarizes the status of the Company’s stock options outstanding, vested and exercisable at December 31, 2018 : Options Outstanding, Vested and Exercisable Range of Exercise Prices Shares Weighted- Average Exercise Price $8.00 to $15.00 35,500 $ 9.53 $15.01 to $21.00 25,466 18.74 $21.01 to $28.00 101,509 24.30 Total 162,475 $ 20.21
Restricted Stock Activity Under Company's Stock Plans	Restricted stock and restricted stock unit activity under the Company’s stock-based compensation plans is shown below: Restricted Stock Restricted Stock Units Number Weighted- Average Fair Value Number Weighted- Average Fair Value Outstanding at December 31, 2017 * 182,267 $ 42.64 1,046,999 $ 42.26 Granted — — 444,063 60.64 Vested (69,714 ) 40.38 (444,470 ) 38.36 Forfeited (8,930 ) 59.77 (93,014 ) 50.75 Outstanding at December 31, 2018 * 103,623 $ 42.68 953,578 $ 51.81 * Excludes 9,641 and 11,058 restricted stock units vested during the years ended December 31, 2018 and 2017 , respectively. As of December 31, 2018 and 2017 restricted stock units vested for which the underlying common stock is yet to be issued are 155,753 and 146,112 , respectively. Performance restricted stock unit activity under the Company’s stock plans is shown below: Revenue Based PRSUs Market Condition Based PRSUs Number Weighted Avg Fair Value Number Weighted Avg Fair Value Outstanding at December 31, 2017 113,190 $ 48.13 113,174 $ 60.80 Granted 55,268 60.58 55,262 70.97 Adjustment upon final determination of level of performance goal achievement* (44,467 ) 48.57 (14,896 ) 67.94 Vested (2,459 ) 48.57 (32,028 ) 67.94 Forfeited (21,179 ) 51.51 (21,176 ) 63.78 Outstanding at December 31, 2018 100,353 $ 54.07 100,336 $ 62.43 * Represents adjustment of shares issued in respect of PUs and MUs granted in February 2016 upon certification of the level of achievement of the performance targets for such awards for which the underlying common stock was issued subsequent to December 31, 2018.
Weighted Average Valuation Assumptions for Market Condition Performance Restricted Stock Units	The fair value of each MU granted to employees is estimated on the date of grant using the following weighted average assumptions: Year ended December 31, 2018 2017 2016 Dividend yield — — — Expected life (years) 2.86 2.86 2.85 Risk free interest rate 2.38 % 1.40 % 0.88 % Volatility 21.79 % 23.78 % 28.00 %

Impact of Adoption of Account_2

Impact of Adoption of Accounting Guidance on Prior Years Presentation and Disclosures (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Summary of affects of new accounting pronouncements	The effect of the adoption of ASU No. 2016-18 (Topic 230) on 2017 and 2016 financial information is summarized as follows: Year ended December 31, Year ended December 31, 2017 2016 Previously reported As revised Effect of change Increase/(Decrease) Previously reported As revised Effect of change Increase/(Decrease) Consolidated statements of cash flows Net cash provided by operating activities $ 113,140 $ 113,159 $ 19 $ 100,258 $ 102,395 $ 2,137 Effect of exchange rate changes on cash, cash equivalents and restricted cash $ 3,711 $ 3,935 $ 224 $ (5,033 ) $ (5,122 ) $ (89 ) Net increase/(decrease) in cash, cash equivalents and restricted cash $ (126,360 ) $ (126,117 ) $ 243 $ 7,832 $ 9,880 $ 2,048 Cash, cash equivalents and restricted cash - beginning of year $ 213,155 $ 220,394 $ 7,239 $ 205,323 $ 210,514 $ 5,191 Cash, cash equivalents and restricted cash - end of year $ 86,795 $ 94,277 $ 7,482 $ 213,155 $ 220,394 $ 7,239 The effect of the adoption of ASU No. 2017-07 (Topic 715) on 2017 and 2016 financial information is summarized as follows: Year ended December 31, Year ended December 31, 2017 2016 Previously reported As revised Effect of change Increase/(Decrease) Previously reported As revised Effect of change Increase/(Decrease) Location in consolidated statements of income Cost of revenues $ 495,586 $ 495,142 $ (444 ) $ 447,956 $ 447,718 $ (238 ) General and administrative expenses $ 102,567 $ 102,515 $ (52 ) $ 88,648 $ 88,616 $ (32 ) Selling and marketing expenses $ 53,383 $ 53,379 $ (4 ) $ 50,582 $ 50,579 $ (3 ) Other income, net $ 11,859 $ 11,359 $ (500 ) $ 15,408 $ 15,135 $ (273 ) Year ended December 31, Year ended December 31, 2017 2016 Cost of revenues previously reported Cost of revenues as revised Effect of change Increase/(Decrease) Cost of revenues previously reported Cost of revenues as revised Effect of change Increase/(Decrease) Segment information (refer Note 3) Insurance $ 159,529 $ 159,433 $ (96 ) $ 146,203 $ 146,151 $ (52 ) Healthcare $ 49,483 $ 49,412 $ (71 ) $ 44,098 $ 44,060 $ (38 ) TT&L $ 41,409 $ 41,337 $ (72 ) $ 41,962 $ 41,923 $ (39 ) F&A $ 51,445 $ 51,362 $ (83 ) $ 48,302 $ 48,258 $ (44 ) All Other $ 56,697 $ 56,638 $ (59 ) $ 61,050 $ 61,019 $ (31 ) Analytics $ 137,023 $ 136,960 $ (63 ) $ 106,341 $ 106,307 $ (34 ) Operating Expenses $ 194,499 $ 194,443 $ (56 ) $ 173,810 $ 173,775 $ (35 ) Foreign exchange gain, interest expense and other income, net $ 12,809 $ 12,309 $ (500 ) $ 19,662 $ 19,389 $ (273 )

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Summary of Revenues and Reimbursements (Details) - USD ($) $ in Thousands

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

Disaggregation of Revenue [Line Items]

Revenue recognition contract terms

The typical length of a contract is 3 to 5 years for our operations management contracts.

Impact on adoption of accounting standard update

$ 454

[1]

$ 454

[1]

$ 1,453

[2]

Revenues and reimbursements

$ 234,903

$ 231,124

$ 210,112

$ 206,973

197,875

$ 192,345

$ 189,057

$ 183,033

$ 883,112

762,310

[3]

685,988

[3]

Reimbursement revenue

Disaggregation of Revenue [Line Items]

Revenues and reimbursements

$ 20,796

17,982

21,812

Minimum

Disaggregation of Revenue [Line Items]

Payment terms

30 days

Maximum

Disaggregation of Revenue [Line Items]

Payment terms

60 days

Retained Earnings

Disaggregation of Revenue [Line Items]

Impact on adoption of accounting standard update

$ 454

[1]

$ 454

[1]

$ (4,546)

[2]

[1]

Refer to Note 2(d) to the consolidated financial statements for details.

[2]

Refer to Note 2(p) to the consolidated financial statements for details.

[3]

Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Allowance for doubtful accounts	$ 956	$ 2,923
Unbilled accounts receivable	$ 63,952	$ 49,125

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Property and Equipment, Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2018
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Minimum | Network equipment and computers
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Software
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Motor vehicles
Property, Plant and Equipment [Line Items]
Estimated useful life	2 years
Maximum | Network equipment and computers
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum | Software
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Motor vehicles
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Lived Intangible Assets Amortized over their Estimated Useful Lives (Detail)	12 Months Ended
	Dec. 31, 2018
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	3 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	15 years
Leasehold benefits | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	3 years
Leasehold benefits | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	8 years
Developed technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	5 years
Developed technology | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	10 years
Non-compete agreements | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	1 year
Non-compete agreements | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	5 years
Trade names and trademarks | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	3 years
Trade names and trademarks | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangible assets	10 years

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Share-Based Compensation (Details) - USD ($) $ in Thousands		Jun. 19, 2015	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Excess tax benefit for stock-based compensation			$ 7,227	$ 9,797		$ 0
Impact on adoption of ASU 2016-09				(454)	[1]	(1,453)	[2]
Deferred tax effect			$ 8,445	695
Accounting Standards Update 2016-09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred tax effect				1,453
Additional Paid-in Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Impact on adoption of ASU 2016-09	[2]					(5,999)
Additional Paid-in Capital | Accounting Standards Update 2016-09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Impact on adoption of ASU 2016-09				5,999
Retained Earnings
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Impact on adoption of ASU 2016-09				(454)	[1]	$ 4,546	[2]
Retained Earnings | Accounting Standards Update 2016-09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Impact on adoption of ASU 2016-09				$ 4,546
Revenue Based PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares an employee can earn			200.00%
Revenue Based PRSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares an employee can earn			200.00%
Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based percentage			100.00%
Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan) | Revenue Based PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based percentage			50.00%
Vesting period			3 years
Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan) | Market Condition Based PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based percentage			50.00%
Vesting period			3 years
Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan) | Market Condition Based PRSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares an employee can earn			200.00%
[1]	Refer to Note 2(d) to the consolidated financial statements for details.
[2]	Refer to Note 2(p) to the consolidated financial statements for details.

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - Forecast $ in Thousands	Jan. 01, 2019USD ($)
Right-of-use asset	$ 81,000
Operating lease liability	$ 90,000

Segment & Geographical Inform_3

Segment & Geographical Information - Narrative (Detail)	12 Months Ended
	Dec. 31, 2018operating_segment
Segment Reporting [Abstract]
Number of operating segments	8
Number of operating segments, operations management	6
Number of operating segments, industry focused	5
Number of operating segments, finance and accounting	1
Number of operating segments, company provides operations management services	6
Number of operating segments, non-operations management services	2

Segment & Geographical Inform_4

Segment & Geographical Information - Revenues and Cost of Revenues for Company's Reportable Segments (Detail)		1 Months Ended	3 Months Ended								12 Months Ended
		Dec. 31, 2017USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)operating_segment		Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net			$ 234,903,000	$ 231,124,000	$ 210,112,000	$ 206,973,000	$ 197,875,000	$ 192,345,000	$ 189,057,000	$ 183,033,000	$ 883,112,000		$ 762,310,000	[1]	$ 685,988,000	[1]
Cost of revenues											584,855,000	[1],[2]	495,142,000	[1],[2]	447,718,000
Gross profit			79,955,000	78,967,000	70,463,000	68,872,000	68,616,000	69,268,000	65,323,000	63,961,000	298,257,000	[2]	267,168,000	[1],[2]	238,270,000	[1],[2]
Operating expenses	[1]										248,436,000		194,443,000		173,775,000
Foreign exchange gain, interest expense and other income, net											10,549,000		12,309,000		19,389,000
Income tax expense											3,397,000		36,146,000	[1]	22,151,000	[1]
Loss from equity-method investment		$ 0									247,000		0	[1],[3]	0	[1],[3]
Net income attributable to ExlService Holdings, Inc. stockholders			$ 3,857,000	$ 15,249,000	$ 14,462,000	$ 23,158,000	$ (9,355,000)	$ 21,077,000	$ 20,378,000	$ 16,788,000	$ 56,726,000		48,888,000	[1],[3]	61,733,000	[1],[3]
Number of operating segments, industry focused | operating_segment											5
Number of operating segments, finance and accounting | operating_segment											1
BPM and related services
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											$ 597,822,000		552,367,000		520,254,000
Analytics services
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											285,290,000		209,943,000		165,734,000
Insurance
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											258,144,000		234,794,000		206,327,000
Cost of revenues											174,921,000		159,433,000		146,151,000
Gross profit											83,223,000		75,361,000		60,176,000
Healthcare
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											84,391,000		77,013,000		68,656,000
Cost of revenues											66,768,000		49,412,000		44,060,000
Gross profit											17,623,000		27,601,000		24,596,000
TT&L
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											70,237,000		70,951,000		69,366,000
Cost of revenues											41,066,000		41,337,000		41,923,000
Gross profit											29,171,000		29,614,000		27,443,000
F&A
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											97,941,000		86,527,000		79,416,000
Cost of revenues											59,155,000		51,362,000		48,258,000
Gross profit											38,786,000		35,165,000		31,158,000
All Other
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											87,109,000		83,082,000		96,489,000
Cost of revenues											58,341,000		56,638,000		61,019,000
Gross profit											28,768,000		26,444,000		35,470,000
Analytics
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net											285,290,000		209,943,000		165,734,000
Cost of revenues											184,604,000		136,960,000		106,307,000
Gross profit											$ 100,686,000		$ 72,983,000		$ 59,427,000
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[2]	Exclusive of depreciation and amortization.
[3]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.

Segment & Geographical Inform_5

Segment & Geographical Information - Revenues and Property and Equipment, Net Based on Geographical Information (Details) - USD ($) $ in Thousands	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
Revenues, net
Revenues and reimbursements	$ 234,903	$ 231,124	$ 210,112	$ 206,973	$ 197,875	$ 192,345	$ 189,057	$ 183,033	$ 883,112	$ 762,310	[1]	$ 685,988	[1]
Property, Plant and Equipment, net
Property and equipment, net	73,510				66,757				73,510	66,757
United States
Revenues, net
Revenues and reimbursements									732,589	626,336		554,945
Property, Plant and Equipment, net
Property and equipment, net	28,254				16,371				28,254	16,371
United Kingdom
Revenues, net
Revenues and reimbursements									114,515	108,640		109,905
Rest of World
Revenues, net
Revenues and reimbursements									36,008	27,334		21,138
Property, Plant and Equipment, net
Property and equipment, net	3,119				3,026				3,119	3,026
Total Non-United States
Revenues, net
Revenues and reimbursements									150,523	135,974		$ 131,043
India
Property, Plant and Equipment, net
Property and equipment, net	36,152				39,143				36,152	39,143
Philippines
Property, Plant and Equipment, net
Property and equipment, net	$ 5,985				$ 8,217				$ 5,985	$ 8,217
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) - Summary of Quarterly Results (Detail) - USD ($) $ / shares in Units, $ in Thousands	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
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Revenues, net	$ 234,903	$ 231,124	$ 210,112	$ 206,973	$ 197,875	$ 192,345	$ 189,057	$ 183,033	$ 883,112		$ 762,310	[1]	$ 685,988	[1]
Gross profit(1)	79,955	78,967	70,463	68,872	68,616	69,268	65,323	63,961	298,257	[2]	267,168	[1],[2]	238,270	[1],[2]
Net income	$ 3,857	$ 15,249	$ 14,462	$ 23,158	$ (9,355)	$ 21,077	$ 20,378	$ 16,788	$ 56,726		$ 48,888	[1],[3]	$ 61,733	[1],[3]
Earnings per share:
Basic (in dollars per share)	$ 0.11	$ 0.44	$ 0.42	$ 0.67	$ (0.27)	$ 0.62	$ 0.60	$ 0.50	$ 1.65		$ 1.44	[1]	$ 1.84	[1]
Diluted (in dollars per share)	$ 0.11	$ 0.43	$ 0.41	$ 0.66	$ (0.27)	$ 0.60	$ 0.58	$ 0.48	$ 1.62		$ 1.39	[1]	$ 1.79	[1]
Weighted-average number of shares used in computing earnings per share:
Basic (in shares)	34,388,025	34,458,520	34,511,777	34,446,265	34,086,711	33,838,374	33,819,320	33,845,560	34,451,008		33,897,916	[1]	33,566,367	[1]
Diluted (in shares)	34,921,388	35,207,991	35,142,388	35,302,926	34,086,711	35,043,987	34,993,226	35,108,882	35,030,984		35,110,210	[1]	34,563,319	[1]
Stock compensation expense	$ 6,590	$ 5,344	$ 6,893	$ 5,074	$ 6,270	$ 5,708	$ 5,107	$ 5,956	$ 23,901		$ 23,041		$ 19,770
Amortization of intangibles	$ 5,951	$ 6,718	$ 3,761	$ 3,947	$ 3,483	$ 3,487	$ 3,507	$ 3,498	$ 20,377		$ 13,975		$ 11,873
Weighted average potentially dilutive shares considered anti-dilutive and not included in computing diluted earnings per share (in shares)									121,344		151,961		92,538
Convertible Debt Securities
Weighted-average number of shares used in computing earnings per share:
Weighted average potentially dilutive shares considered anti-dilutive and not included in computing diluted earnings per share (in shares)					0
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[2]	Exclusive of depreciation and amortization.
[3]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.

Revenues, net - Narrative (Deta

Revenues, net - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017		Dec. 31, 2016	[2]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on adoption of accounting standard update			$ 454,000	[1]	$ 1,453,000
Accounts receivable not billed	$ 63,952,000		49,125,000
Contract liability, revenue recognized	9,147,000
Capitalized contract cost, net	713,000
Increase in capitalized contract costs	567,000
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on adoption of accounting standard update			454,000	[1]	$ (4,546,000)
Impact of adoption of Topic 606 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on adoption of accounting standard update			454,000
Contract Acquisition Costs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Capitalized contract acquisition costs		$ 454,000
Capitalized contract acquisition costs, amount amortized	308,000
Impairment loss in relation to costs capitalized	0
Contract Fulfillment Costs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Capitalized contract cost, net	4,051,000		$ 2,769,000
Increase in capitalized contract costs	2,216,000
Capitalized contract acquisition costs, amount amortized	934,000
Impairment loss in relation to costs capitalized	$ 0
[1]	Refer to Note 2(d) to the consolidated financial statements for details.
[2]	Refer to Note 2(p) to the consolidated financial statements for details.

Revenues, net - Contracts with

Revenues, net - Contracts with Customer, Receivables and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Accounts receivable, net	$ 164,752	$ 135,705
Contract assets	5,445	2,643
Contract liabilities
Deferred revenue (advance payments portion)	6,345	9,311
Consideration received from customer for transitions activities	$ 1,669	$ 1,601

Other Income, net - Summary of

Other Income, net - Summary of Other Income, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Other Nonoperating Income (Expense) [Abstract]
Interest and dividend income	$ 1,873		$ 1,625		$ 1,673
Gain on sale and mark-to-market of mutual funds	9,970		8,766		8,087
Change in fair value of earn-out consideration	0		0	[1]	4,060	[1]
Others, net	1,146		968		1,315
Other income, net	$ 12,989	[2]	$ 11,359	[3]	$ 15,135	[3]
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[3]	These are reclassified to net income and are included in other income, net in the consolidated statements of income. Refer to Note 21 to the consolidated financial statements.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	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
Numerator:
Net income	$ 3,857	$ 15,249	$ 14,462	$ 23,158	$ (9,355)	$ 21,077	$ 20,378	$ 16,788	$ 56,726	$ 48,888	[1],[2]	$ 61,733	[1],[2]
Denominators:
Basic weighted average common shares outstanding (in shares)	34,388,025	34,458,520	34,511,777	34,446,265	34,086,711	33,838,374	33,819,320	33,845,560	34,451,008	33,897,916	[2]	33,566,367	[2]
Dilutive effect of share based awards (in shares)									579,976	1,212,294		996,952
Diluted weighted average common shares outstanding (in shares)	34,921,388	35,207,991	35,142,388	35,302,926	34,086,711	35,043,987	34,993,226	35,108,882	35,030,984	35,110,210	[2]	34,563,319	[2]
Earnings per share attributable to ExlService Holdings, Inc. stockholders:
Basic (in dollars per share)	$ 0.11	$ 0.44	$ 0.42	$ 0.67	$ (0.27)	$ 0.62	$ 0.60	$ 0.50	$ 1.65	$ 1.44	[2]	$ 1.84	[2]
Diluted (in dollars per share)	$ 0.11	$ 0.43	$ 0.41	$ 0.66	$ (0.27)	$ 0.60	$ 0.58	$ 0.48	$ 1.62	$ 1.39	[2]	$ 1.79	[2]
Weighted average potentially dilutive shares considered anti-dilutive and not included in computing diluted earnings per share (in shares)									121,344	151,961		92,538
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Cash, Cash Equivalents and Re_3

Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents		$ 95,881	$ 86,795	$ 213,155
Restricted cash (current)		5,608	3,674	3,846
Restricted cash (non-current)		2,642	3,808	3,393
Total cash, cash equivalents and restricted cash	[1]	$ 104,131	$ 94,277	$ 220,394	$ 210,514
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.

Property and Equipment, net - S

Property and Equipment, net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Owned Assets:
Owned assets, gross	$ 228,850	$ 207,318
Less: Accumulated depreciation and amortization	(155,798)	(141,059)
Owned assets, net	73,052	66,259
Assets under capital leases:
Assets under capital leases, gross	1,459	1,818
Less: Accumulated depreciation and amortization	(1,001)	(1,320)
Assets under capital leases, net	458	498
Property and equipment, net	73,510	66,757
Network equipment and computers
Owned Assets:
Owned assets, gross	$ 85,921	77,587
Network equipment and computers | Minimum
Owned Assets:
Estimated useful life	3 years
Network equipment and computers | Maximum
Owned Assets:
Estimated useful life	5 years
Software
Owned Assets:
Owned assets, gross	$ 69,752	59,325
Software | Minimum
Owned Assets:
Estimated useful life	3 years
Software | Maximum
Owned Assets:
Estimated useful life	5 years
Leasehold improvements
Owned Assets:
Owned assets, gross	$ 39,533	38,857
Assets under capital leases:
Assets under capital leases, gross	$ 778	941
Leasehold improvements | Minimum
Owned Assets:
Estimated useful life	3 years
Leasehold improvements | Maximum
Owned Assets:
Estimated useful life	8 years
Office furniture and equipment
Owned Assets:
Owned assets, gross	$ 20,097	19,667
Assets under capital leases:
Assets under capital leases, gross	$ 53	167
Office furniture and equipment | Minimum
Owned Assets:
Estimated useful life	3 years
Office furniture and equipment | Maximum
Owned Assets:
Estimated useful life	8 years
Motor vehicles
Owned Assets:
Owned assets, gross	$ 635	638
Assets under capital leases:
Assets under capital leases, gross	$ 628	710
Motor vehicles | Minimum
Owned Assets:
Estimated useful life	2 years
Motor vehicles | Maximum
Owned Assets:
Estimated useful life	5 years
Buildings
Owned Assets:
Estimated useful life	30 years
Owned assets, gross	$ 1,140	1,245
Land
Owned Assets:
Owned assets, gross	746	815
Capital work in progress
Owned Assets:
Owned assets, gross	$ 11,026	$ 9,184

Property and Equipment, net - D

Property and Equipment, net - Depreciation and Amortization Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 28,189	$ 24,574	$ 22,707
Depreciation & amortization
Property, Plant and Equipment [Line Items]
Effect of the foreign exchange gains (losses) upon settlement of cash flow hedges	$ 153	$ 435

Property and Equipment, net - I

Property and Equipment, net - Internally Developed Software Costs, Included under Software (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Cost	$ 8,783	$ 2,571
Less : Accumulated amortization	(2,393)	(976)
Net	6,390	1,595
Amortization expense	$ 1,417	$ 640	$ 336

Business Combinations, Goodwi_3

Business Combinations, Goodwill and Intangible Assets - Narrative (Details) - USD ($)	Jul. 01, 2018	Dec. 22, 2017	Jun. 19, 2015	Feb. 28, 2019	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Business Acquisition [Line Items]
Restricted common stock issued for business acquisition							$ 4,080,000	$ 0	[1]	$ 0	[1]
Acquisition related costs							1,315,000	826,000
Vesting period			4 years
Goodwill impairment							14,229,000
Goodwill					$ 349,984,000	$ 349,984,000	349,984,000	204,481,000		186,770,000
Impairment recorded					(5,827,000)	(5,827,000)	(5,827,000)	0
Intangible assets, net					94,595,000	94,595,000	94,595,000	48,058,000
Trade names and trademarks
Business Acquisition [Line Items]
Impairment recorded					(278,000)	(278,000)	(278,000)	0
Impairment charges					278,000
Intangible assets, net					4,035,000	4,035,000	4,035,000	1,917,000
Developed technology
Business Acquisition [Line Items]
Impairment recorded					0	0	0	0
Intangible assets, net					22,501,000	22,501,000	22,501,000	7,086,000
Customer relationships
Business Acquisition [Line Items]
Impairment recorded					(5,549,000)	(5,549,000)	(5,549,000)	0
Impairment charges					5,549,000
Intangible assets, net					67,874,000	67,874,000	67,874,000	38,498,000
SCIO
Business Acquisition [Line Items]
Total purchase consideration	$ 245,044,000
Revenue of acquiree since acquisition date						40,038,000
Goodwill	$ 163,751,000
SCIO | Trade names and trademarks
Business Acquisition [Line Items]
Weighted average useful life	3 years
SCIO | Developed technology
Business Acquisition [Line Items]
Weighted average useful life	5 years
SCIO | Customer relationships
Business Acquisition [Line Items]
Weighted average useful life	10 years
Health Integrated, Inc.
Business Acquisition [Line Items]
Total purchase consideration		$ 22,811,000
Initial purchase consideration		22,811,000
Maximum contingent consideration		5,000,000
Contingent cash consideration					0	0	0	920,000
Goodwill		$ 14,229,000			0	0	0
Intangible assets, net								0
Health Integrated, Inc. | Trade names and trademarks
Business Acquisition [Line Items]
Weighted average useful life		2 years
Health Integrated, Inc. | Developed technology
Business Acquisition [Line Items]
Weighted average useful life		1 year
Health Integrated, Inc. | Customer relationships
Business Acquisition [Line Items]
Weighted average useful life		7 years
Restricted Stock | SCIO
Business Acquisition [Line Items]
Stock issued during period (in shares)	69,459
Restricted common stock issued for business acquisition	$ 4,080,000
Restricted Stock Units | Health Integrated, Inc. | Subsequent Event
Business Acquisition [Line Items]
Issued number of shares of restricted stock (in shares)				4,444
Issued shares of restricted stock, fair value				$ 275,000
Vesting period				4 years
Minimum | SCIO
Business Acquisition [Line Items]
Initial purchase consideration	236,500,000
Revolving Credit Facility | SCIO
Business Acquisition [Line Items]
Utilized revolver credit facility to finance acquisition	$ 233,000,000
Healthcare
Business Acquisition [Line Items]
Goodwill impairment							14,229,000
Goodwill					$ 19,276,000	$ 19,276,000	$ 19,276,000	$ 35,233,000		$ 19,276,000
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.

Business Combinations, Goodwi_4

Business Combinations, Goodwill and Intangible Assets - Purchase Price Allocation - SCIO (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jul. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
Liabilities:
Goodwill	$ 349,984		$ 204,481	$ 186,770
SCIO
Assets:
Cash and cash equivalents		$ 9,842
Restricted cash		2,790
Accounts receivable		19,924
Other current assets		2,076
Property and equipment		1,824
Other assets		1,751
Assets acquired, excluding goodwill		111,107
Liabilities:
Current liabilities		(12,482)
Deferred tax liabilities, net		(17,132)
Other non-current liabilities		(200)
Liabilities		(29,814)
Net assets acquired		81,293
Goodwill		163,751
Total purchase consideration		245,044
Customer relationships | SCIO
Assets:
Intangible assets		47,800
Developed technology | SCIO
Assets:
Intangible assets		21,400
Trade names and trademarks | SCIO
Assets:
Intangible assets		$ 3,700

Business Combinations, Goodwi_5

Business Combinations, Goodwill and Intangible Assets - Supplemental Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
SCIO
Business Acquisition [Line Items]
Revenues	$ 924,172	$ 834,158
Net income	$ 55,756	$ 45,827
Earnings per share:
Basic (in dollars per share)	$ 1.62	$ 1.35
Diluted (in dollars per share)	$ 1.59	$ 1.30
Health Integrated, Inc.
Business Acquisition [Line Items]
Revenues	$ 801,101	$ 729,938
Net income	$ 46,998	$ 58,232
Earnings per share:
Basic (in dollars per share)	$ 1.39	$ 1.73
Diluted (in dollars per share)	$ 1.34	$ 1.68

Business Combinations, Goodwi_6

Business Combinations, Goodwill and Intangible Assets - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 22, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 349,984	$ 204,481		$ 186,770
Health Integrated, Inc.
Business Acquisition [Line Items]
Tangible Assets			$ 5,475
Liabilities			(5,733)
Goodwill	$ 0		14,229
Total purchase consideration			22,811
Health Integrated, Inc. | Customer relationships
Business Acquisition [Line Items]
Intangible assets			6,760
Health Integrated, Inc. | Developed technology
Business Acquisition [Line Items]
Intangible assets			1,510
Health Integrated, Inc. | Trade names and trademarks
Business Acquisition [Line Items]
Intangible assets			$ 570

Business Combinations, Goodwi_7

Business Combinations, Goodwill and Intangible Assets - Summary of Company's Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Beginning Balance	$ 204,481	$ 186,770
Acquisitions	163,751	15,957
Measurement period adjustments	(1,728)
Currency translation adjustments	(2,291)	1,754
Impairment charges	(14,229)
Ending Balance	349,984	204,481
Insurance
Goodwill [Roll Forward]
Beginning Balance	38,333	38,110
Acquisitions	0	0
Measurement period adjustments	0
Currency translation adjustments	(130)	223
Impairment charges	0
Ending Balance	38,203	38,333
Healthcare
Goodwill [Roll Forward]
Beginning Balance	35,233	19,276
Acquisitions	0	15,957
Measurement period adjustments	(1,728)
Currency translation adjustments	0	0
Impairment charges	(14,229)
Ending Balance	19,276	35,233
TT&L
Goodwill [Roll Forward]
Beginning Balance	13,679	12,983
Acquisitions	0	0
Measurement period adjustments	0
Currency translation adjustments	(982)	696
Impairment charges	0
Ending Balance	12,697	13,679
F&A
Goodwill [Roll Forward]
Beginning Balance	48,372	47,537
Acquisitions	0	0
Measurement period adjustments	0
Currency translation adjustments	(1,179)	835
Impairment charges	0
Ending Balance	47,193	48,372
All Other
Goodwill [Roll Forward]
Beginning Balance	5,326	5,326
Acquisitions	0	0
Measurement period adjustments	0
Currency translation adjustments	0	0
Impairment charges	0
Ending Balance	5,326	5,326
Analytics
Goodwill [Roll Forward]
Beginning Balance	63,538	63,538
Acquisitions	163,751	0
Measurement period adjustments	0
Currency translation adjustments	0	0
Impairment charges	0
Ending Balance	227,289	$ 63,538
Health Integrated, Inc.
Goodwill [Roll Forward]
Measurement period adjustments	(1,728)
Ending Balance	$ 0

Business Combinations, Goodwi_8

Business Combinations, Goodwill and Intangible Assets - Summary of Company's Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 181,272	$ 108,884
Accumulated Amortization	(80,850)	(60,826)
Accumulated Impairment	(5,827)	0
Total	94,595	48,058
Intangible assets, gross	182,172	109,784
Intangible assets, net	95,495	48,958
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	129,790	82,165
Accumulated Amortization	(56,367)	(43,667)
Accumulated Impairment	(5,549)	0
Total	67,874	38,498
Leasehold benefits
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	2,644	2,888
Accumulated Amortization	(2,567)	(2,596)
Accumulated Impairment	0	0
Total	77	292
Developed technology
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	37,154	15,835
Accumulated Amortization	(14,653)	(8,749)
Accumulated Impairment	0	0
Total	22,501	7,086
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	2,045	2,045
Accumulated Amortization	(1,937)	(1,780)
Accumulated Impairment	0	0
Total	108	265
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	9,639	5,951
Accumulated Amortization	(5,326)	(4,034)
Accumulated Impairment	(278)	0
Total	4,035	1,917
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, trade names and trademarks	$ 900	$ 900

Business Combinations, Goodwi_9

Business Combinations, Goodwill and Intangible Assets - Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	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
Business Combinations, Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets	$ 5,951	$ 6,718	$ 3,761	$ 3,947	$ 3,483	$ 3,487	$ 3,507	$ 3,498	$ 20,377	$ 13,975	$ 11,873

Business Combinations, Goodw_10

Business Combinations, Goodwill and Intangible Assets - Weighted Average Life of Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2018
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average life of intangible assets	7 years 11 months 4 days
Leasehold benefits
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average life of intangible assets	4 months 28 days
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average life of intangible assets	4 years 4 months 2 days
Non-compete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average life of intangible assets	8 months 19 days
Trade names and trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average life of intangible assets	3 years 1 month 9 days

Business Combinations, Goodw_11

Business Combinations, Goodwill and Intangible Assets - Estimated Future Amortization of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Business Combinations, Goodwill and Intangible Assets Disclosure [Abstract]
2,019	$ 21,543
2,020	14,442
2,021	12,743
2,022	11,331
2,023	9,042
2024 and thereafter	25,494
Total	$ 94,595	$ 48,058

Investment in Equity Affiliate

Investment in Equity Affiliate (Details) - USD ($) number in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	[1],[2]	Dec. 31, 2016	[1],[2]	Dec. 12, 2017
Schedule of Equity Method Investments [Line Items]
Loss from equity-method investment	$ 0	$ 247,000	$ 0		$ 0
Corridor
Schedule of Equity Method Investments [Line Items]
Aggregate cost							$ 3,000,000
Ownership interest							0.00%
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Other Current Assets (Details)

Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Derivative instruments	$ 4,059	$ 10,938
Advances to suppliers	2,910	2,451
Receivables from statutory authorities	14,145	7,598
Contract assets	1,201	401
Deferred contract fulfillment costs	1,236	474
Others	4,689	7,720
Other current assets	$ 28,240	$ 29,582

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Lease deposits	$ 8,891	$ 8,776
Derivative instruments	1,971	7,361
Deposits with statutory authorities	6,259	6,492
Term deposits	315	6,909
Contract assets	4,244	2,242
Deferred contract fulfillment costs	2,815	2,295
Others	6,520	2,294
Other assets	$ 31,015	$ 36,369

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts Payable and Accrued Liabilities, Current [Abstract]
Accrued expenses	$ 44,711	$ 43,235
Derivative instruments	3,204	555
Client liabilities	6,933	8,982
Other current liabilities	9,321	8,594
Accrued expenses and other current liabilities	$ 64,169	$ 61,366

Other Non-current liabilities -

Other Non-current liabilities - Summary of Non-Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Liabilities, Noncurrent [Abstract]
Derivative instruments	$ 3,075	$ 322
Unrecognized tax benefits	804	892
Deferred rent	7,834	8,176
Retirement benefits	3,616	3,377
Deferred transition revenue	945	1,034
Others	247	2,401
Other non-current liabilities	$ 16,521	$ 16,202

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Cumulative foreign currency translation gain/(loss)	$ (84,105)	$ (58,405)
Unrealized gain/(loss) on cash flow hedges, net of taxes of $115 and $4,918, respectively	(333)	11,932
Retirement benefits, net of taxes of ($53) and ($74), respectively	971	763	$ (498)
Accumulated other comprehensive gain/(loss)	(83,467)	(45,710)
Unrealized gain on cash flow hedges, taxes	115	4,918
Retirement benefits, taxes	$ (53)	$ (74)

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Mutual funds	$ 142,408	$ 162,906
Derivative financial instruments	6,030	18,298
Total	148,438	181,204
Liabilities
Derivative financial instruments	6,279	877
Fair value of earn-out consideration		920
Total	6,279	1,797
Level 1
Assets
Mutual funds	142,408	162,906
Derivative financial instruments	0	0
Total	142,408	162,906
Liabilities
Derivative financial instruments	0	0
Fair value of earn-out consideration		0
Total	0	0
Level 2
Assets
Mutual funds	0	0
Derivative financial instruments	6,030	18,298
Total	6,030	18,298
Liabilities
Derivative financial instruments	6,279	877
Fair value of earn-out consideration		0
Total	6,279	877
Fair value of convertible notes	130,510
Level 3
Assets
Mutual funds	0	0
Derivative financial instruments	0	0
Total	0	0
Liabilities
Derivative financial instruments	0	0
Fair value of earn-out consideration	0	920
Total	$ 0	$ 920

Derivatives and Hedge Account_3

Derivatives and Hedge Accounting - Narrative (Detail) € in Thousands, £ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2018EUR (€)	Dec. 31, 2018GBP (£)	Dec. 31, 2017USD ($)	Dec. 31, 2017EUR (€)	Dec. 31, 2017GBP (£)
Derivative Instruments, Gain (Loss) [Line Items]
Net derivative losses which could be reclassified into earnings within the next 12 months	$ 885
Maximum outstanding term of cash flow hedges	45 months
Derivatives Designated as Hedging Instruments | Derivatives in cash flow hedging relationships | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts outstanding	$ 362,435			$ 300,757
Derivative not designated as hedging instruments | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts outstanding	125,503	€ 512	£ 15,616	$ 97,949	€ 848	£ 17,947
Forward contracts | Derivatives Designated as Hedging Instruments | Derivatives in cash flow hedging relationships | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts outstanding	$ 6,900

Derivatives and Hedge Account_4

Derivatives and Hedge Accounting - Summary of Fair Value of Foreign Currency Exchange Contracts (Detail) - Foreign exchange contracts - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Derivative designated as hedging instruments | Other current assets
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, asset	$ 4,022	$ 10,892
Derivative designated as hedging instruments | Other assets
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, asset	1,971	7,360
Derivative designated as hedging instruments | Accrued expense and other current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, liability	3,137	481
Derivative designated as hedging instruments | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, liability	3,075	322
Derivative not designated as hedging instruments | Other current assets
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, asset	37	46
Derivative not designated as hedging instruments | Accrued expense and other current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency exchange contracts, liability	$ 67	$ 74

Derivatives and Hedge Account_5

Derivatives and Hedge Accounting - Summary of Effect of Foreign Currency Exchange Contracts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
(Loss)/gain recognized in consolidated statements of income	$ (4,787)	$ (2,839)	[1]	$ (5,597)	[1]
Derivatives in cash flow hedging relationships | Derivative designated as hedging instruments | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
(Loss)/gain recognized in AOCI	13,919	(19,802)		(5,129)
Reclassification out of Accumulated Other Comprehensive Income | Derivatives in cash flow hedging relationships | Derivative designated as hedging instruments | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
(Loss)/gain recognized in consolidated statements of income	0	0		(2,669)
Reclassification out of Accumulated Other Comprehensive Income | Fair value hedge | Derivative designated as hedging instruments | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
(Loss)/gain recognized in consolidated statements of income	$ 3,224	$ (5,056)		$ (4,790)
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Derivatives and Hedge Account_6

Derivatives and Hedge Accounting - Location of Gain or Loss Recognized (Details) - USD ($) $ in Thousands	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
Derivative Instruments, Gain (Loss) [Line Items]
Cost of revenues									$ 584,855	[1],[2]	$ 495,142	[1],[2]	$ 447,718
General & administrative expenses									116,202	[1]	102,515	[1]	88,616
Selling & marketing expenses									63,612	[1]	53,379	[1]	50,579
Depreciation & amortization									48,566		38,549	[1]	34,580
Foreign exchange gain/(loss), net									4,787		2,839	[1]	5,597	[1]
Net income attributable to ExlService Holdings, Inc. stockholders	$ 3,857	$ 15,249	$ 14,462	$ 23,158	$ (9,355)	$ 21,077	$ 20,378	$ 16,788	56,726		48,888	[1],[3]	61,733	[1],[3]
Reclassification out of Accumulated Other Comprehensive Income | Derivatives Designated as Hedging Instruments | Derivatives in cash flow hedging relationships | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Cost of revenues									2,481		5,465		0
General & administrative expenses									443		960		0
Selling & marketing expenses									44		103		0
Depreciation & amortization									181		371		0
Foreign exchange gain/(loss), net									0		0		2,669
Net income attributable to ExlService Holdings, Inc. stockholders									3,149		6,899		2,669
Reclassification out of Accumulated Other Comprehensive Income | Derivatives Designated as Hedging Instruments | Fair value hedge | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange gain/(loss), net									(3,224)		5,056		4,790
Reclassification out of Accumulated Other Comprehensive Income | Derivative not designated as hedging instruments | Fair value hedge | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange gain/(loss), net									$ (3,224)		$ 5,056		$ 4,790
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[2]	Exclusive of depreciation and amortization.
[3]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.

Borrowings and Credit Arrange_3

Borrowings and Credit Arrangements (Detail)	Oct. 01, 2018USD ($)$ / shares	Nov. 21, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)	[1]	Jul. 02, 2018USD ($)	Feb. 23, 2015USD ($)	Oct. 24, 2014USD ($)
Credit Facilities [Line Items]
Current portion of long-term borrowings			$ 21,423,000	$ 10,318,000
Long term borrowings			263,241,000	50,391,000
Debt offering expense			762,000	790,000	[1]	$ 0
Allocation of equity component related to the convertible senior notes, net of tax and issuance costs			12,555,000
Structured payable			302,114,000
Structured Payables
Credit Facilities [Line Items]
Current portion of long-term borrowings			1,423,000	318,000
Long term borrowings			691,000	391,000
Structured payable			2,114,000	709,000
3.50% Convertible Senior Notes due October 1, 2024 | Convertible Notes Payable
Credit Facilities [Line Items]
Debt instrument face amount	$ 150,000,000
Interest rate	3.50%
Interest expense			1,313,000
Conversion rate	0.0133
Conversion price (in dollars per share) | $ / shares	$ 75
Net proceeds from convertible notes	$ 149,000,000
Debt issuance costs	1,000,000
Debt offering expense	325,000
Liability component of debt issuance costs	1,176,000
Equity component of debt issuance costs	149,000
Unamortized debit issuance costs			$ 1,127,000
Convertible notes, liability component	133,077,000
Convertible senior notes, interest rate			5.75%
Allocation of equity component related to the convertible senior notes, net of tax and issuance costs	$ 16,923,000
Debt instrument, convertible, remaining discount amortization period	6 years
Debt discount amortization			$ 600,000
Structured payable			150,000,000
Revolving Credit Facility
Credit Facilities [Line Items]
Revolving credit facility			150,000,000	60,000,000
Current portion of long-term borrowings			20,000,000	10,000,000
Long term borrowings			130,000,000	50,000,000
Unamortized debt issuance costs			1,006,000	$ 773,000
Repayments of credit facility	$ 150,000,000
Structured payable			$ 150,000,000
Revolving Credit Facility | Credit Facility
Credit Facilities [Line Items]
Revolving credit facility										$ 50,000,000
Option to increase additional credit facility									$ 50,000,000
Line of credit interest rate during period			2.99%
Revolving Credit Facility | New Credit Agreement
Credit Facilities [Line Items]
Revolving credit facility		$ 200,000,000
Option to increase additional credit facility								$ 100,000,000
Line of credit interest rate during period			3.40%	3.00%
Line of credit , maximum borrowing capacity								$ 300,000,000
Unrestricted domestic cash and cash equivalents			$ 50,000,000
Interest coverage ratio, minimum		3.5
Interest coverage ratio, maximum		3
Revolving Credit Facility | New Credit Agreement | Minimum
Credit Facilities [Line Items]
Commitment fee percentage range on unused credit facility		0.15%
Revolving Credit Facility | New Credit Agreement | Maximum
Credit Facilities [Line Items]
Commitment fee percentage range on unused credit facility		0.30%
Revolving Credit Facility | New Credit Agreement | Prime Rate | Minimum
Credit Facilities [Line Items]
Basis spread on variable rate		0.00%
Revolving Credit Facility | New Credit Agreement | Prime Rate | Maximum
Credit Facilities [Line Items]
Basis spread on variable rate		0.75%
Revolving Credit Facility | New Credit Agreement | London Interbank Offered Rate (LIBOR) | Minimum
Credit Facilities [Line Items]
Basis spread on variable rate		1.00%
Revolving Credit Facility | New Credit Agreement | London Interbank Offered Rate (LIBOR) | Maximum
Credit Facilities [Line Items]
Basis spread on variable rate		1.75%
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.

Borrowings and Credit Arrange_4

Borrowings and Credit Arrangements Principle Maturities of Borrowings and Credit Arrangements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Credit Facilities [Line Items]
2,019	$ 21,423
2,020	28,691
2,021	28,000
2,022	74,000
2,023	0
Thereafter	150,000
Total maturities of borrowings and credit arrangements	302,114
Revolving Credit Facility
Credit Facilities [Line Items]
2,019	20,000
2,020	28,000
2,021	28,000
2,022	74,000
2,023	0
Thereafter	0
Total maturities of borrowings and credit arrangements	150,000
Convertible Notes Payable | 3.50% Convertible Senior Notes due October 1, 2024
Credit Facilities [Line Items]
2,019	0
2,020	0
2,021	0
2,022	0
2,023	0
Thereafter	150,000
Total maturities of borrowings and credit arrangements	150,000
Structured Payables
Credit Facilities [Line Items]
2,019	1,423
2,020	691
2,021	0
2,022	0
2,023	0
Thereafter	0
Total maturities of borrowings and credit arrangements	$ 2,114	$ 709

Capital Structure (Detail)

Capital Structure (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)ClassOfCommonStock$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Feb. 28, 2017USD ($)	Dec. 30, 2014USD ($)
Equity, Class of Treasury Stock [Line Items]
Number of classes of common stock outstanding | ClassOfCommonStock	1
Acquisition of restricted stock from employees in connection with withholding tax payments (in shares) | shares	51,446	69,154	17,676
Withholding tax payments related to the vesting of restricted stock for total consideration	$ 3,122,000	$ 3,267,000	$ 807,000
Weighted average purchase price per share prior to the vesting date (in dollars per share) | $ / shares	$ 60.68	$ 47.24	$ 45.65
2014 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock authorized by board of directors up to					$ 20,000,000
Common stock shares purchased under the repurchase program (in shares) | shares		761,154
Common stock aggregate purchase price including commissions		$ 40,187,000
Common stock average purchase price per share (in dollars per share) | $ / shares		$ 52.80	$ 47.78
2014 Repurchase Program | Minimum
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock authorized by board of directors up to					$ 20,000,000
2017 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Additional authorized amount				$ 100,000,000
Authorized increase in repurchase amount, 2018				40,000,000
Authorized increase in repurchase amount, 2019				40,000,000
2017 Repurchase Program | Maximum
Equity, Class of Treasury Stock [Line Items]
Authorized increase in repurchase amount				$ 40,000,000
2014 and 2017 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Common stock shares purchased under the repurchase program (in shares) | shares	674,604		364,056
Common stock aggregate purchase price including commissions	$ 39,987,000		$ 17,396,000
Common stock average purchase price per share (in dollars per share) | $ / shares	$ 59.27

Employee Benefit Plans - Summar

Employee Benefit Plans - Summary of Change in Projected Benefit Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in projected benefit obligation:
Projected benefit obligation at the beginning of the year	$ 10,305	$ 9,711
Acquisition	326	0
Service cost	1,735	1,933	$ 1,601
Interest cost	714	645	599
Benefits paid	(1,066)	(1,001)
Actuarial (gain)/loss	(134)	(1,471)
Effect of exchange rate changes	(836)	488
Projected benefit obligation at the end of the year	11,044	10,305	$ 9,711
Unfunded amount–non-current	3,616	3,377
Unfunded amount–current	8	13
Total accrued liability	3,624	3,390
Accumulated benefit obligation	$ 7,239	$ 7,022

Employee Benefit Plans - Net Pe

Employee Benefit Plans - Net Period Benefit Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Service cost	$ 1,735	$ 1,933	$ 1,601
Interest cost	714	645	599
Expected return on plan assets	(514)	(401)	(416)
Amortization of actuarial (gain)/loss	(153)	256	90
Net periodic benefit cost	$ 1,782	$ 2,433	$ 1,874

Employee Benefit Plans - Summ_2

Employee Benefit Plans - Summary of Components Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Abstract]
Net actuarial gain/(loss)	$ 940	$ 697	$ (831)
Net prior service cost	(22)	(8)	(9)
Deferred taxes	53	74	342
Accumulated other comprehensive gain/(loss), net of tax	$ 971	$ 763	$ (498)

Employee Benefit Plans - Narrat

Employee Benefit Plans - Narrative (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Accumulated other comprehensive loss, expected to be recognized over the next fiscal year	$ 156
Percentage of expected return on plan assets	8.00%
Percentage of discretionary contributions towards 401(k) Plan, maximum	4.00%
Company's contribution to the 401(k) Plan	$ 3,423	$ 2,709	$ 2,383
Contribution to various defined contribution plans	$ 7,614	$ 7,116	$ 6,306

Employee Benefit Plans - Summ_3

Employee Benefit Plans - Summary of Weighted Average Actuarial Assumptions (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	7.50%	7.00%	6.80%
Rate of increase in compensation levels	8.20%	9.10%	9.20%
Expected long term rate of return on plan assets per annum	7.30%	8.30%	9.00%

Employee Benefit Plans - Summ_4

Employee Benefit Plans - Summary of Expected Benefit Payments (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2,019	$ 1,820
2,020	1,692
2,021	1,621
2,022	1,424
2,023	1,332
2024 to 2028	$ 4,577

Employee Benefit Plans - Change

Employee Benefit Plans - Change in Plan Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at the beginning of the year	$ 6,915	$ 5,640
Business acquisition	231
Actual return	779	202
Employer contribution	1,175	1,700
Benefits paid	(1,059)	(1,001)
Effect of exchange rate changes	(621)	374
Plan assets at the ending of the year	$ 7,420	$ 6,915

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments under Capital Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
2,019	$ 283
2,020	163
2,021	120
2,022	58
2023 and thereafter	49
Total minimum lease payments	673
Less: amount representing interest	135
Present value of minimum lease payments	538
Less: current portion	223	$ 267
Long term capital lease obligation	$ 315	$ 331

Leases - Future Minimum Lease_2

Leases - Future Minimum Lease Payments under Non-Cancelable Operating Lease Agreements Expiring After December 31, 2016 (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2,019	$ 23,431
2,020	20,039
2,021	16,924
2,022	14,804
2,023	12,859
2024 and thereafter	26,114
Total operating lease payments	$ 114,171

Leases - Rent Expense and Defer

Leases - Rent Expense and Deferred Rent (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Leases [Abstract]
Rent expense	$ 25,573	$ 24,015	$ 21,382
Cancelable and non-cancelable operating leases	$ 8,782	$ 8,959

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Income Tax Disclosure [Abstract]
Domestic	$ (24,442)	$ 4,626		$ 12,652
Foreign	84,812	80,408		71,232
Income before income tax expense	$ 60,370	$ 85,034	[1]	$ 83,884	[1]
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Current provision:
Domestic	$ (13,249)	$ 17,407		$ 7,107
Foreign	17,271	18,008		18,428
Total	4,022	35,415		25,535
Deferred provision/(benefit):
Domestic	(1,999)	2,618		(2,506)
Foreign	1,374	(1,887)		(878)
Total	(625)	731	[1]	(3,384)	[1]
Income tax expense	$ 3,397	$ 36,146	[2]	$ 22,151	[2]
[1]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.
[2]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Income Taxes - Summary of Effec

Income Taxes - Summary of Effective Income Tax Rate Differs from Amount Computed by Applying U.S. Federal Statutory Income Tax Rate to Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Income Tax Disclosure [Abstract]
Expected tax expense	$ 12,678	$ 29,762		$ 29,361
Change in valuation allowance	0	(21)		22
Impact of tax holiday	(5,448)	(4,396)		(4,027)
Foreign tax rate differential	5,014	(2,616)		(2,716)
Deferred tax (benefit)/provision	(3,915)	(1,887)		(878)
Unrecognized tax benefits and interest	(88)	(3,905)		495
State taxes, net of Federal taxes	2,200	339		202
Non-deductible expenses	3,066	825		144
US Tax Reform Act impact	176	29,185		0
Excess tax benefit on stock-based compensation	(7,227)	(9,797)		0
Research & Development credit	(1,500)	(844)		(890)
Other	(1,559)	(499)		438
Income tax expense	$ 3,397	$ 36,146	[1]	$ 22,151	[1]
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Detail)	12 Months Ended						24 Months Ended
	Dec. 31, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)$ / shares		Dec. 31, 2016USD ($)$ / shares		Dec. 31, 2014operation_center	Dec. 31, 2018USD ($)
Income Taxes [Line Items]
Income tax expense	$ 3,397,000	$ 36,146,000	[1]	$ 22,151,000	[1]
Effective tax rates	5.60%	42.50%
Transition tax	$ 176,000	$ 27,236,000					$ 27,412,000
Re-measured net deferred tax assets and liabilities, income tax expense		1,949,000
Measurement period increase to transition tax obligation	176,000						176,000
Transition tax obligation	27,412,000						27,412,000
Excess tax benefit on stock-based compensation	$ (7,227,000)	$ (9,797,000)		$ 0
Number of operation centers, income tax holiday expired | operation_center						3
Effective tax rate in Philippines post tax exemption	5.00%
Effect of diluted earnings per share, tax holiday (in dollars per share) | $ / shares	$ 0.16	$ 0.13		$ 0.12
Operating loss carryforward valuation allowance	$ 20,000	$ 20,000					20,000
Valuation allowance related to tax credit carry forward	79,000	88,000					79,000
Unrecognized tax benefits that would impact tax rate if recognized	804,000						804,000
Unrecognized Tax Benefits, Interest on Income Taxes Expense	0	0		$ 315,000
Accrued interest on unrecognized tax benefits	$ 0	68,000					0
First Five Years
Income Taxes [Line Items]
Percentage of tax exemption on profit	100.00%
Five to Ten Years
Income Taxes [Line Items]
Percentage of tax exemption on profit	50.00%
Expiration 2,032
Income Taxes [Line Items]
Operating loss carryforwards	$ 444,000	$ 1,554,000					$ 444,000
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.

Income Taxes - Summary of Com_2

Income Taxes - Summary of Components of Deferred Tax Balances (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Depreciation and amortization	$ 3,731	$ 2,183
Stock-based compensation	8,614	7,647
Accrued employee costs and other expenses	3,596	3,673
Tax credit carry forward	0	1,474
Net operating loss carry forward	1,113	2,068
Unrealized exchange loss	6,671	252
Deferred rent	2,255	2,064
Others	1,380	1,007
Deferred tax assets	27,360	20,368
Valuation allowance	(99)	(108)
Deferred tax assets	27,261	20,260
Deferred tax liabilities:
Unrealized exchange gain	115	5,069
Intangible assets	19,289	4,648
Unamortized discount on convertible senior notes	4,105	0
Others	5,595	1,958
Deferred tax liabilities:	29,104	11,675
Deferred tax liabilities	$ (1,843)
Net deferred tax assets		$ 8,585

Income Taxes - Summary of Activ

Income Taxes - Summary of Activity Related to Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of January 1	$ 824	$ 3,087	$ 2,797
Increases related to prior year tax positions	0	0	156
Decreases related to prior year tax positions	(320)	(2,520)	0
Increases related to current year tax positions	300	169	178
Effect of exchange rate changes, increase	0	88
Effect of exchange rate changes, decrease			44
December 31	$ 804	$ 824	$ 3,087

Stock Based Compensation - Narr

Stock Based Compensation - Narrative (Detail) - shares	Jun. 19, 2015	Feb. 28, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiring period of equity options to employees	10 years
Vesting period	4 years
2015 Stock Options Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares available for grant (in shares)	3,175,000
Number of shares available for grant (in shares)			3,207,975
2015 Stock Options Plan | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued, stock-based compensation plans (in shares)		34,487

Stock Based Compensation - Cost

Stock Based Compensation - Costs Related to Company's Stock-Based Compensation Plan (Detail) - USD ($) $ in Thousands	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
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expenses	$ 6,590	$ 5,344	$ 6,893	$ 5,074	$ 6,270	$ 5,708	$ 5,107	$ 5,956	$ 23,901	$ 23,041	$ 19,770
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expenses									4,924	4,600	3,664
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expenses									10,371	10,363	8,372
Selling and marketing expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expenses									$ 8,606	$ 8,078	$ 7,734

Stock Based Compensation - Stoc

Stock Based Compensation - Stock Options Narrative (Details) - Employee Stock Option - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%
Unrecognized compensation cost for unvested stock options	$ 0
Total grant date fair value of option vested in period	0	$ 0	$ 706,000
Intrinsic value of options exercised	$ 4,446,000	$ 23,027,000	$ 12,911,000

Stock Based Compensation - St_2

Stock Based Compensation - Stock Based Compensation Stock Option Activity (Detail) - Employee Stock Option - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, outstanding, beginning balance (in shares)	259,563
Number of options, granted (in shares)	0
Number of options, exercised (in shares)	(97,088)
Number of options, forfeited (in shares)	0
Number of options, outstanding, ending balance (in shares)	162,475	259,563
Number of options, vested and exercisable at December 31, 2017 (in shares)	162,475
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-average exercise price, outstanding, beginning balance (in dollars per share)	$ 18.03
Weighted-average exercise price, granted (in dollars per share)	0
Weighted-average exercise price, exercised (in dollars per share)	14.39
Weighted-average exercise price, forfeited (in dollars per share)	0
Weighted-average exercise price, outstanding, ending balance (in dollars per share)	20.21	$ 18.03
Weighted average exercise price, vested and exercisable at December 31, 2017 (in dollars per share)	$ 20.21
Aggregate intrinsic value, outstanding	$ 5,267	$ 10,985
Aggregate intrinsic value, exercised	$ 4,446	$ 23,027	$ 12,911
Weighted-average remaining contractual life, outstanding, ending balance	2 years 2 months 27 days	2 years 9 months 3 days
Aggregate intrinsic value, vested and exercisable at December 31, 2017	$ 5,267
Weighted-average remaining contractual life, vested and exercisable at December 31, 2017	2 years 2 months 27 days

Stock Based Compensation - Comp

Stock Based Compensation - Company's Stock Options Outstanding and Stock Options Vested and Exercisable (Detail)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding (in shares) | shares	162,475
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 20.21
$8.00 to $15.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range limit (in dollars per share)	8
Range of Exercise Prices, upper range limit (in dollars per share)	$ 15
Options Outstanding (in shares) | shares	35,500
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 9.53
$15.01 to $21.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range limit (in dollars per share)	15.01
Range of Exercise Prices, upper range limit (in dollars per share)	$ 21
Options Outstanding (in shares) | shares	25,466
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 18.74
$21.01 to $28.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, lower range limit (in dollars per share)	21.01
Range of Exercise Prices, upper range limit (in dollars per share)	$ 28
Options Outstanding (in shares) | shares	101,509
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 24.30

Stock Based Compensation - Rest

Stock Based Compensation - Restricted Stock Activity Under Company's Stock Plans (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number, outstanding, beginning balance (in shares)	182,267
Number, granted (in shares)	0
Number, vested (in shares)	(69,714)
Number, forfeited (in shares)	(8,930)
Number, outstanding, ending balance (in shares)	103,623	182,267
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average fair value, outstanding, beginning balance (in dollars per share)	$ 42.64
Weighted-average fair value, granted (in dollars per share)	0
Weighted-average fair value, vested (in dollars per share)	40.38
Weighted-average fair value, forfeited (in dollars per share)	59.77
Weighted-average fair value, outstanding, ending balance (in dollars per share)	$ 42.68	$ 42.64
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number, outstanding, beginning balance (in shares)	1,046,999
Number, granted (in shares)	444,063
Number, vested (in shares)	(444,470)
Number, forfeited (in shares)	(93,014)
Number, outstanding, ending balance (in shares)	953,578	1,046,999
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average fair value, outstanding, beginning balance (in dollars per share)	$ 42.26
Weighted-average fair value, granted (in dollars per share)	60.64
Weighted-average fair value, vested (in dollars per share)	38.36
Weighted-average fair value, forfeited (in dollars per share)	50.75
Weighted-average fair value, outstanding, ending balance (in dollars per share)	$ 51.81	$ 42.26
Restricted stock units vested for which underlying common stock to be issued (in shares)	9,641	11,058
Restricted stock units vested (in shares)	155,753	146,112

Stock Based Compensation - Re_2

Stock Based Compensation - Restricted Stock and RSU Narrative (Details) - Restricted Stock and Restricted Stock Units - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 36,460
Cost not yet recognized, period for recognition	2 years 6 months 18 days
Weighted-average fair value of restricted stock and RSUs granted (in dollars per share)	$ 60.64	$ 48.02	$ 48.97
Number of restricted stock units, vested	$ 19,865	$ 19,430	$ 10,761

Stock Based Compensation - Perf

Stock Based Compensation - Performance Based Stock Awards Narrative (Details) - USD ($) $ in Thousands	Jun. 19, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based percentage		100.00%
Revenue Based PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares an employee can earn		200.00%
Number, granted (in shares)		55,268
Revenue Based PRSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares an employee can earn		200.00%
Revenue Based PRSUs | Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based percentage		50.00%
Vesting period		3 years
Revenue Based PRSUs | Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan) | Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of award vesting rights				33.33%
Revenue Based PRSUs | Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan) | Year Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of award vesting rights			33.33%
Market Condition Based PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number, granted (in shares)		55,262
Market Condition Based PRSUs | Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based percentage		50.00%
Vesting period		3 years
Market Condition Based PRSUs | Amendment And Restatement Of The 2006 Omnibus Award Plan (2015 Plan) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares an employee can earn		200.00%
Performance Based Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost		$ 7,652
Cost not yet recognized, period for recognition		1 year 8 months 26 days

Stock Based Compensation Share-

Stock Based Compensation Share-based Compensation - Summary of Weighted Average Valuation Assumptions for Market Condition Performance Restricted Stock Units (Details) - Market Condition Based PRSUs	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected life (years)	2 years 10 months 10 days	2 years 10 months 10 days	2 years 10 months 6 days
Risk free interest rate	2.38%	1.40%	0.88%
Volatility	21.79%	23.78%	28.00%

Stock Based Compensation - Pe_2

Stock Based Compensation - Performance Restricted Stock Activity (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Revenue Based PRSUs
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number, outstanding, beginning balance (in shares) | shares	113,190
Number, granted (in shares) | shares	55,268
Number, adjustment upon final determination of level of performance goal achievement (in shares) | shares	(44,467)
Number, vested (in shares) | shares	(2,459)
Number, forfeited (in shares) | shares	(21,179)
Number, outstanding, ending balance (in shares) | shares	100,353
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average fair value, outstanding, beginning balance (in dollars per share) | $ / shares	$ 48.13
Weighted-average fair value, granted (in dollars per share) | $ / shares	60.58
Weighted-average fair value, adjustment upon final determination of level of performance goal achievement (in shares) | $ / shares	48.57
Weighted-average fair value, vested (in dollars per share) | $ / shares	48.57
Weighted-average fair value, forfeited (in dollars per share) | $ / shares	51.51
Weighted-average fair value, outstanding, ending balance (in dollars per share) | $ / shares	$ 54.07
Market Condition Based PRSUs
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number, outstanding, beginning balance (in shares) | shares	113,174
Number, granted (in shares) | shares	55,262
Number, additionally issued due to achievement of higher-than-target performance (in shares) | shares	(14,896)
Number, vested (in shares) | shares	(32,028)
Number, forfeited (in shares) | shares	(21,176)
Number, outstanding, ending balance (in shares) | shares	100,336
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average fair value, outstanding, beginning balance (in dollars per share) | $ / shares	$ 60.80
Weighted-average fair value, granted (in dollars per share) | $ / shares	70.97
Weighted-average fair value, adjustment upon final determination of level of performance goal achievement (in shares) | $ / shares	67.94
Weighted-average fair value, vested (in dollars per share) | $ / shares	67.94
Weighted-average fair value, forfeited (in dollars per share) | $ / shares	63.78
Weighted-average fair value, outstanding, ending balance (in dollars per share) | $ / shares	$ 62.43

Related Party Disclosures (Deta

Related Party Disclosures (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Oct. 01, 2018
Debt Instrument [Line Items]
Revenue from related party	$ 225,000	$ 1,748,000	$ 0
Accounts receivable from related party	5,000	$ 140,000
Debt outstanding	302,114,000
Convertible Notes Payable | 3.50% Convertible Senior Notes due October 1, 2024
Debt Instrument [Line Items]
Debt instrument face amount				$ 150,000,000
Interest rate				3.50%
Debt outstanding	150,000,000
Interest accrued	$ 1,313,000

Commitments and Contingencies (

Commitments and Contingencies (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Purchase commitments, net of advances	$ 6,277
Percentage of export-oriented units established	100.00%
Litigation, settlement amount	$ 2,400
Settlement payments made during the period	1,200
Aggregate disputed amount amount related to transfer pricing and permanent establishment	18,177	$ 18,065
Total bank guarantees and deposits in respect of contingencies	8,171	8,573
Amounts paid as deposits in respect of contingencies	6,273	6,499
Bank guarantee issued	$ 1,899	$ 2,074

Impact of Adoption of Account_3

Impact of Adoption of Accounting Guidance on Prior Years Presentation and Disclosures - Effect of the Adoption of the ASU No. 2017-07 and 2016-18 (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues		$ 584,855	[1],[2]	$ 495,142	[1],[2]	$ 447,718
General & administrative expenses		116,202	[1]	102,515	[1]	88,616
Selling & marketing expenses		63,612	[1]	53,379	[1]	50,579
Other income, net		12,989	[1]	11,359	[3]	15,135	[3]
Operating expenses	[1]	248,436		194,443		173,775
Foreign exchange gain, interest expense and other income, net		10,549		12,309		19,389
Net cash provided by operating activities	[4]	92,435		113,159		102,395
Effect of exchange rate changes on cash, cash equivalents and restricted cash	[4]	(2,868)		3,935		(5,122)
Net increase/(decrease) in cash, cash equivalents and restricted cash	[4]	9,854		(126,117)		9,880
Cash, cash equivalents and restricted cash - beginning of year	[4]	94,277		220,394		210,514
Cash, cash equivalents and restricted cash - end of year	[4]	104,131		94,277		220,394
Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				495,586		447,956
General & administrative expenses				102,567		88,648
Selling & marketing expenses				53,383		50,582
Other income, net				11,859		15,408
ASU No. 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating expenses				194,443		173,775
Foreign exchange gain, interest expense and other income, net				12,309		19,389
ASU No. 2017-07 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating expenses				194,499		173,810
Foreign exchange gain, interest expense and other income, net				12,809		19,662
ASU No. 2017-07 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				(444)		(238)
General & administrative expenses				(52)		(32)
Selling & marketing expenses				(4)		(3)
Other income, net				(500)		(273)
Operating expenses				(56)		(35)
Foreign exchange gain, interest expense and other income, net				(500)		(273)
ASU No. 2016-18
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities				113,159		102,395
Effect of exchange rate changes on cash, cash equivalents and restricted cash				3,935		(5,122)
Net increase/(decrease) in cash, cash equivalents and restricted cash				(126,117)		9,880
Cash, cash equivalents and restricted cash - beginning of year		94,277		220,394		210,514
Cash, cash equivalents and restricted cash - end of year				94,277		220,394
ASU No. 2016-18 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities				113,140		100,258
Effect of exchange rate changes on cash, cash equivalents and restricted cash				3,711		(5,033)
Net increase/(decrease) in cash, cash equivalents and restricted cash				(126,360)		7,832
Cash, cash equivalents and restricted cash - beginning of year		86,795		213,155		205,323
Cash, cash equivalents and restricted cash - end of year				86,795		213,155
ASU No. 2016-18 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities				19		2,137
Effect of exchange rate changes on cash, cash equivalents and restricted cash				224		(89)
Net increase/(decrease) in cash, cash equivalents and restricted cash				243		2,048
Cash, cash equivalents and restricted cash - beginning of year		7,482		7,239		5,191
Cash, cash equivalents and restricted cash - end of year				7,482		7,239
Insurance
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues		174,921		159,433		146,151
Insurance | ASU No. 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				159,433		146,151
Insurance | ASU No. 2017-07 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				159,529		146,203
Insurance | ASU No. 2017-07 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				(96)		(52)
Healthcare
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues		66,768		49,412		44,060
Healthcare | ASU No. 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				49,412		44,060
Healthcare | ASU No. 2017-07 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				49,483		44,098
Healthcare | ASU No. 2017-07 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				(71)		(38)
TT&L
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues		41,066		41,337		41,923
TT&L | ASU No. 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				41,337		41,923
TT&L | ASU No. 2017-07 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				41,409		41,962
TT&L | ASU No. 2017-07 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				(72)		(39)
F&A
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues		59,155		51,362		48,258
F&A | ASU No. 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				51,362		48,258
F&A | ASU No. 2017-07 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				51,445		48,302
F&A | ASU No. 2017-07 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				(83)		(44)
All Other
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues		58,341		56,638		61,019
All Other | ASU No. 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				56,638		61,019
All Other | ASU No. 2017-07 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				56,697		61,050
All Other | ASU No. 2017-07 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				(59)		(31)
Analytics
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues		$ 184,604		136,960		106,307
Analytics | ASU No. 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				136,960		106,307
Analytics | ASU No. 2017-07 | Previously reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				137,023		106,341
Analytics | ASU No. 2017-07 | Effect of change Increase/(Decrease)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of revenues				$ (63)		$ (34)
[1]	Adjusted pursuant to adoption of ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost. Refer to Note 21 and Note 27 to the consolidated financial statements.
[2]	Exclusive of depreciation and amortization.
[3]	These are reclassified to net income and are included in other income, net in the consolidated statements of income. Refer to Note 21 to the consolidated financial statements.
[4]	Adjusted pursuant to adoption of ASU 2016-18, Statements of Cash Flows, Restricted Cash. Refer to Note 8 and Note 27 to the consolidated financial statements.