CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands		12 Months Ended
		Jan. 31, 2019	Jan. 31, 2018	[3]	Jan. 31, 2017	[3]
Statement of Comprehensive Income [Abstract]
Net loss	[1]	$ (125,497)	$ (109,849)	[2],[4]	$ (75,056)	[2],[4]
Net change in unrealized gains (losses) on available-for-sale securities		179	(202)		10
Foreign currency translation adjustments		(889)	760		(120)
Other comprehensive income (loss)		(710)	558		(110)
Comprehensive loss		$ (126,207)	$ (109,291)		$ (75,166)

[1] See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.

[2] See Note 2 for a summary of adjustments.

[3] See Note 2 for a summary of adjustments.

[4] See Note 2 for a summary of adjustments.