Earnings Per Share (Details) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
		Jun. 20, 2023	Aug. 31, 2023	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Numerators:
Net income | $				$ 184,558	$ 142,968	$ 114,758
Denominators:
Basic (in shares)	[1]			166,341,213	166,651,585	167,746,375
Dilutive effect of share based awards (in shares)				1,820,158	2,517,705	2,043,465
Dilutive effect of conversion premium on the Notes (in shares)				0	0	1,432,550
Diluted (in shares)	[1]			168,161,371	169,169,290	171,222,390
Earnings per share attributable to ExlService Holdings, Inc. stockholders:
Basic (in dollars per share) | $ / shares	[1]			$ 1.11	$ 0.86	$ 0.68
Diluted (in dollars per share) | $ / shares	[1]			$ 1.10	$ 0.85	$ 0.67
Weighted average potentially dilutive shares considered anti-dilutive and not included in computing diluted earnings per share (in shares)				1,628,932	2,830	53,525
Stock split conversion ratio		5	5

[1] Prior period information has been adjusted to reflect the 5-for-1 forward stock split of the Company’s common stock effected in August 2023. Refer to Note 19 – Capital Structure to the consolidated financial statements for further details.