Income Taxes - Components of Income (loss) Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Provision Benefit For Income Taxes [Line Items]
(Loss) income before income taxes	$ 1,428	$ (110,481)	$ (105,470)
United States [Member]
Provision Benefit For Income Taxes [Line Items]
(Loss) income before income taxes	27,000	(102,643)	(92,767)
Foreign [Member]
Provision Benefit For Income Taxes [Line Items]
(Loss) income before income taxes	$ (25,572)	$ (7,838)	$ (12,703)