Income Taxes - Schedule of Provision for Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Income Tax Disclosure [Abstract]
Domestic	$ (158,664)	$ (106,856)
Foreign	1,483	1,520
Loss before provision for income taxes	$ (157,181)	$ (105,336)	$ (100,334)