CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (53,967)	$ (33,240)
Other comprehensive income, net of tax:
Unrealized gain on available-for-sale securities	848	58
Foreign currency translation adjustment	(75)	13
Other comprehensive income	773	71
Total comprehensive loss	$ (53,194)	$ (33,169)