Segment and Geographical Information - Revenues and Cost of Revenues for Company's Reportable Segments (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net		$ 448,366	$ 404,996	$ 884,873	$ 805,639
Cost of revenues	[1]	282,106	253,220	555,530	504,689
Gross profit	[1]	166,260	151,776	329,343	300,950
Operating expenses		104,811	86,965	206,370	176,691
Foreign exchange gain, net, interest expense and other income, net		(1,742)	(255)	(722)	(380)
Income tax expense		13,873	15,554	27,626	23,612
Gain (loss) from equity-method investment		(9)	66	(37)	132
Net income attributable to ExlService Holdings, Inc. stockholders		45,825	49,068	94,588	100,399
Digital operations and solutions
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net		254,580	222,813	500,361	441,613
Analytics services
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net		193,786	182,183	384,512	364,026
Insurance
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net		149,297	128,457	294,436	254,393
Cost of revenues		95,524	84,322	187,816	166,646
Gross profit		53,773	44,135	106,620	87,747
Healthcare
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net		28,098	27,156	54,348	53,859
Cost of revenues		18,802	17,540	36,119	36,349
Gross profit		9,296	9,616	18,229	17,510
Emerging Business
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net		77,185	67,200	151,577	133,361
Cost of revenues		45,069	37,845	86,048	73,815
Gross profit		32,116	29,355	65,529	59,546
Analytics
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net		193,786	182,183	384,512	364,026
Cost of revenues		122,711	113,513	245,547	227,879
Gross profit		$ 71,075	$ 68,670	$ 138,965	$ 136,147

[1] Exclusive of depreciation and amortization expense.