REVENUES (Tables)

9 Months Ended

Sep. 30, 2018

Revenue from Contract with Customer [Abstract]

Impact of Changes After Adoption of Topic 606

The following tables summarize the impacts of changes in accounting policies after adoption of Topic 606 on the Company’s condensed consolidated financial statements for the three and nine months ended September 30, 2018, which primarily resulted from deferring the timing of revenue recognition for contracts that were previously recognized on a cash basis and recognizing revenues from certain license agreements at a point-in-time rather than over time:

	As of September 30, 2018
	As Reported		Balances Without Adoption of Topic 606		Effect of Change Higher/(Lower)
Balance Sheet
Liabilities
Accrued expenses and other current liabilities	$	98,442	$	98,354	$	88
Other noncurrent liabilities	11,804		11,823		(19		)
Stockholders’ equity
Retained earnings	$	699,568	$	699,637	$	(69	)

	Three Months Ended September 30, 2018							Nine Months Ended September 30, 2018
	As Reported		Balances Without Adoption of Topic 606		Effect of Change			As Reported			Balances Without Adoption of Topic 606			Effect of Change
Income Statement
Revenues	$	468,186	$	468,257	$	(71	)	$	1,337,981		$	1,338,069		$	(88	)
Income from operations	$	64,560	$	64,631	$	(71	)	$	167,494		$	167,582		$	(88	)
Provision for/(benefit from) income taxes	$	369	$	385	$	(16	)	$	(9,286	)	$	(9,267	)	$	(19	)
Net income	$	65,618	$	65,673	$	(55	)	$	180,291		$	180,360		$	(69	)

Disaggregation of Revenues

The following tables show the disaggregation of the Company’s revenues by major client location, including a reconciliation of the disaggregated revenues with the reportable segments (Note 12 “Segment Information”) for the three and nine months ended September 30, 2018:

	Three Months Ended September 30, 2018
Reportable Segments	North America		Europe		Russia		Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Client Locations
North America	$	271,551	$	12,536	$	17	$	284,104	$	(27	)	$	284,077
Europe	5,408		146,990		3		152,401		(166		)	152,235
CIS	2,208		142		16,184		18,534		—			18,534
APAC	1,671		11,814		4		13,489		(149		)	13,340
Revenues	$	280,838	$	171,482	$	16,208	$	468,528	$	(342	)	$	468,186

	Nine Months Ended September 30, 2018
Reportable Segments	North America		Europe			Russia			Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Client Locations
North America	$	747,894	$	40,074	—	$	46	—	$	788,014	$	(40	)	$	787,974
Europe	11,234		444,468		—	45		—	455,747		(623		)	455,124
CIS	6,300		233		—	53,192		—	59,725		—			59,725
APAC	3,709		31,545		—	91		—	35,345		(187		)	35,158
Revenues	$	769,137	$	516,320		$	53,374		$	1,338,831	$	(850	)	$	1,337,981

The following tables show the disaggregation of the Company’s revenues by industry vertical, including a reconciliation of the disaggregated revenues with the reportable segments (Note 12 “Segment Information”) for the three and nine months ended September 30, 2018:

	Three Months Ended September 30, 2018
Reportable Segments	North America		Europe		Russia		Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Industry Verticals
Financial Services	$	30,488	$	61,713	$	12,786	$	104,987	$	(189	)	$	104,798
Travel & Consumer	45,690		53,634		1,891		101,215		(122		)	101,093
Software & Hi-Tech	68,572		19,035		569		88,176		—			88,176
Business Information & Media	64,152		17,650		—		81,802		—			81,802
Life Sciences & Healthcare	39,550		5,078		12		44,640		(31		)	44,609
Emerging Verticals	32,386		14,372		950		47,708		—			47,708
Revenues	$	280,838	$	171,482	$	16,208	$	468,528	$	(342	)	$	468,186

	Nine Months Ended September 30, 2018
Reportable Segments	North America		Europe		Russia		Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Industry Verticals
Financial Services	$	79,176	$	190,027	$	43,102	$	312,305	$	(697	)	$	311,608
Travel & Consumer	133,481		155,208		5,356		294,045		(122		)	293,923
Software & Hi-Tech	193,672		59,186		1,957		254,815		—			254,815
Business Information & Media	181,021		54,637		—		235,658		—			235,658
Life Sciences & Healthcare	99,893		15,550		12		115,455		(31		)	115,424
Emerging Verticals	81,894		41,712		2,947		126,553		—			126,553
Revenues	$	769,137	$	516,320	$	53,374	$	1,338,831	$	(850	)	$	1,337,981

The following tables show the disaggregation of the Company’s revenues by contract type including a reconciliation of the disaggregated revenues with the Company’s reportable segments (Note 12 “Segment Information”) for the three and nine months ended September 30, 2018:

	Three Months Ended September 30, 2018
Reportable Segments	North America		Europe		Russia		Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Contract Types
Time-and-material	$	256,549	$	155,797	$	9,441	$	421,787	$	—		$	421,787
Fixed-price	23,241		15,001		6,759		45,001		—			45,001
Licensing	798		173		1		972		—			972
Other revenues	250		511		7		768		(342		)	426
Revenues	$	280,838	$	171,482	$	16,208	$	468,528	$	(342	)	$	468,186

	Nine Months Ended September 30, 2018
Reportable Segments	North America		Europe		Russia		Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Contract Types
Time-and-material	$	704,612	$	471,900	$	29,302	$	1,205,814	$	—		$	1,205,814
Fixed-price	61,716		42,035		24,038		127,789		—			127,789
Licensing	2,098		1,119		12		3,229		—			3,229
Other revenues	711		1,266		22		1,999		(850		)	1,149
Revenues	$	769,137	$	516,320	$	53,374	$	1,338,831	$	(850	)	$	1,337,981

Timing of Revenue Recognition

The following tables show the timing of revenue recognition:

	Three Months Ended September 30, 2018
Reportable Segments	North America		Europe		Russia		Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Timing of Revenue Recognition
Transferred at a point of time	$	194	$	289	$	—	$	483	$	(342	)	$	141
Transferred over time	280,644		171,193		16,208		468,045		—			468,045
Revenues	$	280,838	$	171,482	$	16,208	$	468,528	$	(342	)	$	468,186

	Nine Months Ended September 30, 2018
Reportable Segments	North America		Europe		Russia		Total Segment Revenues		Other Income Included in Segment Revenues			Consolidated Revenues
Timing of Revenue Recognition
Transferred at a point of time	$	832	$	1,351	$	10	$	2,193	$	(850	)	$	1,343
Transferred over time	768,305		514,969		53,364		1,336,638		—			1,336,638
Revenues	$	769,137	$	516,320	$	53,374	$	1,338,831	$	(850	)	$	1,337,981

Revenue Expected to be Recognized in Future Related to Remaining Performance Obligations

The following table includes the estimated revenues expected to be recognized in the future related to performance obligations that are partially or fully unsatisfied as of September 30, 2018. The Company applies a practical expedient and does not disclose the value of unsatisfied performance obligations for contracts that (i) have an original expected duration of one year or less and (ii) contracts for which it recognizes revenues at the amount to which it has the right to invoice for services provided:

	Less than 1 year		1 Year		2 Years		3 Years		Total
Contract Type
Fixed-price	$	4,590	$	568	$	126	$	—	$	5,284

Contract Balances

The following table provides information on the classification of contract assets and liabilities in the condensed consolidated balance sheets:

	As of    September 30,   2018		As of    December 31,   2017
Contract assets included in unbilled revenues	$	19,180	$	7,901
Contract liabilities included in accrued expenses and other current liabilities	$	3,376	$	4,498