Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenues, net		$ 243,509	$ 210,112	$ 483,082	$ 417,085
Cost of revenues	[1]	162,446	139,649	319,686	277,750
Gross profit	[1]	81,063	70,463	163,396	139,335
Operating expenses:
General and administrative expenses		31,228	27,640	63,759	56,906
Selling and marketing expenses		17,647	15,151	35,694	29,103
Depreciation and amortization		12,752	10,582	26,419	21,086
Impairment and restructuring charges		5,580	0	6,807	0
Total operating expenses		67,207	53,373	132,679	107,095
Income from operations		13,856	17,090	30,717	32,240
Foreign exchange gain, net		1,202	1,414	2,462	2,029
Interest expense		(3,864)	(706)	(7,446)	(1,244)
Other income, net		4,102	2,232	8,525	5,766
Income before income tax expense and earnings from equity affiliates		15,296	20,030	34,258	38,791
Income tax expense		2,670	5,510	6,870	1,057
Income before earnings from equity affiliates		12,626	14,520	27,388	37,734
Loss from equity-method investment		62	58	129	114
Net income attributable to ExlService Holdings, Inc. stockholders		$ 12,564	$ 14,462	$ 27,259	$ 37,620
Earnings per share attributable to ExlService Holdings, Inc. stockholders:
Basic (in dollars per share)		$ 0.36	$ 0.42	$ 0.79	$ 1.09
Diluted (in dollars per share)		$ 0.36	$ 0.41	$ 0.78	$ 1.07
Weighted-average number of shares used in computing earnings per share attributable to ExlService Holdings, Inc. stockholders:
Basic (in shares)		34,451,671	34,511,777	34,413,455	34,479,202
Diluted (in shares)		34,702,547	35,142,388	34,768,203	35,222,838

[1] Exclusive of depreciation and amortization.