Derivatives and Hedge Accounting - Location of Gain or Loss Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Cost of revenues	$ 230,462	$ 177,743	$ 659,185	$ 507,265
General and administrative expenses	42,519	36,167	122,898	103,369
Selling and marketing expenses	23,879	21,672	72,034	59,631
Depreciation and amortization expense	14,380	12,305	42,057	36,716
Interest expense	2,442	1,810	4,820	6,804
Income before income tax expense and earnings from equity affiliates	51,434	30,675	145,528	108,478
Income tax effects on above	(12,447)	(4,196)	(34,774)	(22,019)
Net income attributable to ExlService Holdings, Inc. stockholders	39,095	26,507	111,119	86,459
Foreign exchange gain, net	1,504	1,171	4,683	2,958
Loss/gain on derivative financial instruments | Derivatives Designated as Hedging Instruments | Derivatives in cash flow hedging relationships | Derivative financial instruments
Derivative Instruments, Gain (Loss) [Line Items]
Cost of revenues	(1,381)	1,801	1,396	6,643
General and administrative expenses	(109)	223	366	769
Selling and marketing expenses	(6)	11	23	39
Depreciation and amortization expense	(71)	115	96	394
Interest expense	0	0	0	0
Income before income tax expense and earnings from equity affiliates	(1,567)	2,150	1,881	7,845
Income tax effects on above	133	(370)	(802)	(1,186)
Net income attributable to ExlService Holdings, Inc. stockholders	(1,434)	1,780	1,079	6,659
Loss/gain on derivative financial instruments | Derivatives not designated as hedging instruments | Derivative financial instruments
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange gain, net	$ (4,889)	$ (464)	$ (11,245)	$ (1,054)