Goodwill and Intangible Assets, net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross	$ 16,937	$ 12,522
Accumulated Amortization	(5,482)	(3,367)
Net	11,455	9,155
Capitalized internal-use software costs
Finite-Lived Intangible Assets [Line Items]
Gross	15,344	10,859
Accumulated Amortization	(4,446)	(2,487)
Net	10,898	8,372
Software licenses
Finite-Lived Intangible Assets [Line Items]
Gross	1,023	1,093
Accumulated Amortization	(466)	(314)
Net	557	779
Purchased developed technology
Finite-Lived Intangible Assets [Line Items]
Gross	570	570
Accumulated Amortization	(570)	(566)
Net	$ 0	$ 4