Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (59,786)	$ (44,792)	$ (30,447)
Other comprehensive income, net of tax:
Net unrealized gains on investments	451	671	376
Other comprehensive income, net of tax	451	671	376
Comprehensive loss	$ (59,335)	$ (44,121)	$ (30,071)