Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (38,284)	$ (28,147)	$ (40,843)	$ (55,675)
Other comprehensive income (loss), net of taxes:
Foreign currency translation adjustment	(223)	(826)	(386)	(1,001)
Change in unrealized gain (loss) on marketable securities	31	6	46	11
Change in unrealized gain (loss) on cash flow hedges	(438)	(115)	(691)	(129)
Other comprehensive loss	(630)	(935)	(1,031)	(1,119)
Comprehensive loss	$ (38,914)	$ (29,082)	$ (41,874)	$ (56,794)