Derivatives and Hedge Accounting - Location of Gain or Loss Recognized (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Cost of revenues	[1]	$ 253,220	$ 221,207	$ 504,689	$ 428,723
General and administrative expenses		45,605	40,434	92,351	80,379
Selling and marketing expenses		28,238	23,985	57,731	48,155
Depreciation and amortization expense		13,122	14,075	26,609	27,677
Interest expense		3,240	1,502	6,625	2,378
Income before income tax expense and earnings from equity affiliates		64,556	46,828	123,879	94,094
Income tax effects on above		(15,554)	(11,125)	(23,612)	(22,327)
Net income attributable to ExlService Holdings, Inc. stockholders		49,068	35,846	100,399	72,024
Foreign exchange gain/(loss), net		324	1,423	429	3,179
Gain/ (loss) on foreign currency exchange contracts | Derivatives in cash flow hedging relationships | Cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Cost of revenues		(1,141)	1,194	(3,896)	2,777
General and administrative expenses		(133)	181	(375)	475
Selling and marketing expenses		(13)	15	(32)	29
Depreciation and amortization expense		(43)	69	(166)	167
Interest expense		166	0	240	0
Income before income tax expense and earnings from equity affiliates		(1,164)	1,459	(4,229)	3,448
Income tax effects on above		231	(420)	765	(935)
Net income attributable to ExlService Holdings, Inc. stockholders		(933)	1,039	(3,464)	2,513
Gain/ (loss) on foreign currency exchange contracts | Derivatives not designated as hedging instruments | Fair value hedge
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange gain/(loss), net		$ (370)	$ (5,457)	$ 2,158	$ (6,356)

[1] Exclusive of depreciation and amortization expense.