Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Jan. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 204,193	$ 121,024
Deferred revenue	31,103	2,663
Finance and operating lease liabilities	19,068	0
Other reserves	377	346
Gross deferred tax assets	254,741	124,033
Valuation allowance	(136,981)	(101,502)
Total deferred tax assets, net of valuation allowance	117,760	22,531
Deferred tax liability:
Goodwill	(55)	(44)
Depreciable assets	(10,796)	(2,288)
Finance and operating lease right-of-use assets	(12,681)	0
Convertible senior notes	(78,812)	(19,066)
Other liabilities and accruals	(15,559)
Other liabilities and accruals		16
Total deferred tax liability	(117,903)	(21,382)
Net deferred tax liabilities	$ (143)
Net deferred tax assets		$ 1,149