Income Taxes - Summary of the Components of the Company's Loss Before Provision For (Benefit From) Income Taxes (Detail) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Net income (loss) $ (183,619) $ (250,863) $ (183,533)
Domestic      
Net income (loss) $ (183,619) $ (250,863) $ (183,533)