Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2018	Jan. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deposit related to early exercise of unvested options	$ 1,119	$ 2,168
Accrued expenses	3,389	4,297
Redeemable convertible preferred stock warrant liability	0	304
Accrued taxes payable	835	826
Deferred rent, current	520	225
Other	324	543
Accrued expenses and other current liabilities	$ 6,187	$ 8,363