Earnings Per Share - Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerators:
Net income	$ 35,846	$ 28,021	$ 72,024	$ 59,952
Denominators:
Basic weighted average common shares outstanding (in shares)	33,403,411	33,571,074	33,422,618	33,652,146
Dilutive effect of share-based awards (in shares)	427,128	330,063	439,979	336,528
Dilutive effect of conversion premium on the Notes (in shares)	0	488,631	0	364,919
Diluted weighted average common shares outstanding (in shares)	33,830,539	34,389,768	33,862,597	34,353,593
Earnings per share attributable to ExlService Holdings Inc. stockholders:
Basic (in dollars per share)	$ 1.07	$ 0.83	$ 2.15	$ 1.78
Diluted (in dollars per share)	$ 1.06	$ 0.81	$ 2.13	$ 1.75
Weighted average potentially dilutive considered anti-dilutive and not included in computing diluted earnings per share (in shares)	0	1,748	541	874