Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock and additional paid-in capital	Accumulated deficit	Accumulated other comprehensive income (loss)
Beginning balance at Jan. 31, 2019		$ 744,907	$ (492,211)	$ (319)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net		13,516
Issuance of common stock for bonus settlement		2,809
Stock-based compensation		22,846
Net loss	$ (51,966)		(51,966)
Other comprehensive income (loss)				(138)
Ending balance at Apr. 30, 2019	239,444	784,078	(544,177)	(457)
Beginning balance at Jan. 31, 2020	405,344	1,105,576	(701,124)	892
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net		14,708
Issuance of common stock for bonus settlement		9,818
Stock-based compensation		38,038
Net loss	(57,662)		(57,662)
Other comprehensive income (loss)				2,850
Ending balance at Apr. 30, 2020	$ 413,096	$ 1,168,140	$ (758,786)	$ 3,742