Derivatives and Hedge Accounting - Location of Gain or Loss Recognized (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Cost of revenues	[1]	$ 282,106	$ 253,220	$ 555,530	$ 504,689
General and administrative expenses		56,457	45,605	109,700	92,351
Selling and marketing expenses		35,444	28,238	71,414	57,731
Depreciation and amortization expense		12,910	13,122	25,256	26,609
Interest expense		5,328	3,240	8,619	6,625
Income before income tax expense and earnings from equity affiliates		59,707	64,556	122,251	123,879
Income tax effects on above		(13,873)	(15,554)	(27,626)	(23,612)
Net income attributable to ExlService Holdings, Inc. stockholders		45,825	49,068	94,588	100,399
Foreign exchange gain/(loss), net		36	324	395	429
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		(732)	(1,141)	(582)	(3,896)
General and administrative expenses		40	(133)	79	(375)
Selling and marketing expenses		10	(13)	14	(32)
Depreciation and amortization expense		(34)	(43)	(26)	(166)
Interest expense		241	166	483	240
Income before income tax expense and earnings from equity affiliates		(475)	(1,164)	(32)	(4,229)
Income tax effects on above		(207)	231	(309)	765
Net income attributable to ExlService Holdings, Inc. stockholders		(682)	(933)	(341)	(3,464)
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		$ (2,113)	$ (370)	$ (2,073)	$ 2,158

[1] Exclusive of depreciation and amortization expense.