Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Income Tax [Line Items]
Increase related to prior tax positions		$ 4.2
Accrued interest on uncertain tax position	$ 0.0	0.0	$ 0.0
Accrued penalties on uncertain tax position	0.0	0.0	$ 0.0
Income tax benefit carryback under CARES Act		$ 35.9
Net operating losses carryback term due to CARES Act		5 years
State Income Tax [Member]
Income Tax [Line Items]
Net operating loss carryforwards	3.7	$ 5.4
State Income Tax [Member] | Research and Development (R&D) [Member]
Income Tax [Line Items]
Income tax credit	$ 1.1	$ 2.2
Tax credit carryforward term	20 years