Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (10,818)	$ (15,463)
Other comprehensive loss, net of tax:
Net unrealized losses on investments	(427)	(363)
Other comprehensive loss, net of tax	(427)	(363)
Comprehensive loss	$ (11,245)	$ (15,826)