Income Taxes - Schedule of Effective Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Income Tax Disclosure [Abstract]
Income tax benefit at statutory rate	$ (36,997)	$ (21,474)	$ (27,958)
State taxes, net of federal benefit	298	106	564
Impact of foreign income taxes	5,376	5,111	5,555
Stock based compensation	(41,800)	(27,361)	1,741
Non-deductible expenses	2,114	1,238	615
Change in valuation allowance	72,263	40,357	(11,791)
Research and development credits	(1,899)	(1,540)	(1,146)
Prior year true ups	59	135	(144)
Change in tax rate due to the Tax Act	0	0	33,110
Other	(70)	110	741
Provision for (benefit from) income taxes	$ (656)	$ (3,318)	$ 1,287