Stockholders' Equity - Schedule of common stock reserved for future issuance (Detail) - shares	Sep. 30, 2020	Apr. 01, 2020	Mar. 31, 2020
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Conversion of Series A preferred stock (in shares)	10,000		10,000
Options outstanding (in shares)	5,834,682		3,873,888
Options available for future option grants (in shares)	5,101,557		5,283,520
Common stock warrants (in shares)	0		5,750,000
Earnout shares reserved for issuance (in shares)	0		20,000,000
Total (in shares)	11,073,439	2,186,215	34,917,408
Restricted stock units outstanding
Schedule Of Common Stock Reserved For Future Issuance [Line Items]
Restricted stock units outstanding (in shares)	127,200		0