Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	[2]	Jan. 31, 2017	[2]
Statement of Comprehensive Income [Abstract]
Net loss	$ (178,362)	$ (159,878)	[1],[3]	$ (221,532)	[1],[3]
Other comprehensive loss:
Change in unrealized net gain (loss) on available-for-sale securities	1,579	(1,355)		(562)
Comprehensive loss	$ (176,783)	$ (161,233)		$ (222,094)

[1] * As adjusted to reflect the impact of ASU 2016-18 and the full retrospective adoption of

[2] * As adjusted to reflect the impact of the full retrospective adoption of ASC 606 - see Note 2.

[3] *As adjusted to reflect the impact of the full retrospective adoption of ASC 606 - see Note 2.