Earnings per Share - Diluted earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income (loss) available to Virtusa common stockholders	$ 21,158	$ 11,633	$ 6,014	$ 4,747	$ 7,273	$ 11,489	$ 417	$ (7,383)	$ 43,552	$ 11,796	$ (2,709)
Net income (loss) available to Virtusa common stockholders and assumed conversion									$ 43,552	$ 11,796	$ (2,709)
Denominator:
Basic weighted average common shares outstanding (in shares)									30,017,937	29,817,526	29,397,350
Dilutive effect of employee stock options and unvested restricted stock awards and restricted stock units									636,590	842,128
Weighted average shares-diluted (in shares)									30,654,527	30,659,654	29,397,350
Diluted earnings (loss) per share available to Virtusa common stockholders (in dollars per share)	$ 0.66	$ 0.38	$ 0.20	$ 0.15	$ 0.24	$ 0.37	$ 0.01	$ (0.25)	$ 1.42	$ 0.38	$ (0.09)