Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 756	$ (17,078)	$ (17,218)	$ (47,297)
Other comprehensive income (loss), net of tax:
Net change and reclassification of unrealized gains (losses) on investments	(608)	(224)	(1,219)	595
Other comprehensive income (loss), net of tax	(608)	(224)	(1,219)	595
Comprehensive income (loss)	$ 148	$ (17,302)	$ (18,437)	$ (46,702)