Segment Information - Schedule of Financial Information by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Segment Reporting Information [Line Items]
Revenue	$ 211,720	$ 198,292	$ 196,711	$ 187,468	$ 144,515	$ 118,988	$ 112,979	$ 103,459	$ 794,191	$ 479,941	$ 372,293
Contribution margin									607,110	368,529	273,157
Subscription
Segment Reporting Information [Line Items]
Revenue									667,826	406,333	302,617
Contribution margin									577,899	356,214	258,771
Services
Segment Reporting Information [Line Items]
Revenue									126,365	73,608	69,676
Contribution margin									$ 29,211	$ 12,315	$ 14,386