Property and Equipment, Net - Internal-use Software and Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Jan. 31, 2020
Property and Equipment [Line Items]
Depreciation and amortization expense related to property and equipment	$ 2,300	$ 2,000
Internal-use software
Property and Equipment [Line Items]
Internal-use software costs capitalized during the period	1,438	$ 430
Total capitalized internal-use software, net of accumulated amortization	$ 7,554		$ 6,275