Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Tax Credit Carryforward [Line Items]
Increase (decrease) of valuation allowance	$ 35,500,000	$ (2,300,000)	$ (3,100,000)
Unrecognized tax benefits	8,106,000	2,778,000	$ 1,976,000	$ 1,205,000
Unrecognized tax benefits, if recognized, would impact effective tax rate	2,000,000.0
Interest and penalties	300,000	$ 0
Federal Income Tax
Tax Credit Carryforward [Line Items]
Operating loss carryforward	148,000,000.0
Federal Income Tax | Research and Development Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	6,700,000
State Income Tax
Tax Credit Carryforward [Line Items]
Operating loss carryforward	88,200,000
State Income Tax | Research and Development Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	5,900,000
Foreign Tax
Tax Credit Carryforward [Line Items]
Operating loss carryforward	$ 6,800,000