Equity Incentive Plan - Summary of The Black-Scholes Assumptions Used To Value Stock Options At The Grant Dates (Detail)
12 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Maximum      
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Expected term (years) 6 years 1 month 6 days 6 years 1 month 6 days 6 years 3 months 18 days
Expected volatility 68.00% 62.00% 54.00%
Risk-free interest rate 0.50% 2.20% 3.10%
Expected dividend yield 0.00% 0.00% 0.00%
Minimum      
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]      
Expected term (years) 4 years 5 years 5 years
Expected volatility 61.00% 53.00% 52.00%
Risk-free interest rate 0.20% 0.60% 2.50%
Expected dividend yield 0.00% 0.00% 0.00%