CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenues, net		$ 1,122,293	$ 958,434	$ 991,346
Cost of revenues	[1]	690,934	623,936	655,490
Gross profit	[1]	431,359	334,498	335,856
Operating expenses:
General and administrative expenses		142,040	113,891	126,909
Selling and marketing expenses		84,306	60,123	71,842
Depreciation and amortization expense		49,132	50,462	51,981
Impairment and restructuring charges		0	0	8,671
Total operating expenses		275,478	224,476	259,403
Income from operations		155,881	110,022	76,453
Foreign exchange gain, net		4,313	4,432	3,752
Interest expense		(7,561)	(11,190)	(13,612)
Other income, net		6,773	12,065	16,507
Loss on settlement of convertible notes		(12,845)	0	0
Income before income tax expense and earnings from equity affiliates		146,561	115,329	83,100
Income tax expense		31,850	25,626	15,172
Income before earnings from equity affiliates		114,711	89,703	67,928
(Gain)/loss from equity-method investment		47	(227)	(269)
Net income attributable to ExlService Holdings, Inc. stockholders		$ 114,758	$ 89,476	$ 67,659
Earnings per share attributable to ExlService Holdings, Inc. stockholders:
Basic (in dollars per share)		$ 3.42	$ 2.61	$ 1.97
Diluted (in dollars per share)		$ 3.35	$ 2.59	$ 1.95
Weighted-average number of shares used in computing earnings per share attributable to ExlService Holdings Inc. stockholders:
Basic (in shares)		33,549,275	34,273,388	34,350,150
Diluted (in shares)		34,244,478	34,555,164	34,732,683

[1] Exclusive of depreciation and amortization expense.