Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 225,525	$ 203,009	$ 259,016
Other comprehensive (loss) income:
Foreign currency translation gain (loss)	2,142	(1,832)	(11,431)
Unrealized (loss) gain on derivative instrument	(2,095)	3,999
Net unrealized (loss) gain on marketable securities	(303)	1,333	946
Other comprehensive (loss) income	(256)	3,500	(10,485)
Comprehensive income	$ 225,269	$ 206,509	$ 248,531