Income Taxes - Schedule of Geographical Breakdown of Income (Loss) before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Income Tax Disclosure [Abstract]
Domestic	$ (145,428)	$ (117,391)		$ (176,821)
International	(31,845)	(38,598)		(42,824)
Loss before provision for income taxes	$ (177,273)	$ (155,989)	[1]	$ (219,645)	[1]

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