Goodwill and Intangible Assets, net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2018	Jan. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross	$ 18,729	$ 19,175
Accumulated Amortization	(6,866)	(6,300)
Write-offs	0	(1,114)
Net	11,863	11,761
Capitalized internal-use software costs
Finite-Lived Intangible Assets [Line Items]
Gross	17,706	17,511
Accumulated Amortization	(6,282)	(5,172)
Write-offs	0	(1,077)
Net	11,424	11,262
Software licenses
Finite-Lived Intangible Assets [Line Items]
Gross	1,023	1,094
Accumulated Amortization	(584)	(558)
Write-offs	0	(37)
Net	$ 439	499
Purchased developed technology
Finite-Lived Intangible Assets [Line Items]
Gross		570
Accumulated Amortization		(570)
Write-offs		0
Net		$ 0