Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Deferred tax assets:
Federal and state credits	$ 24,394	$ 21,275
Expenses not currently deductible	939	593
Operating lease liabilities	2,144	2,023
Stock-based compensation	3,349	3,203
Foreign deferred	184	132
Gross deferred tax assets	31,010	27,226
Valuation allowance	(17,962)	(14,670)
Total deferred tax assets	13,048	12,556
Deferred tax liabilities
Property and equipment	(1,443)	(1,469)
Operating lease assets	(1,978)	(1,974)
Net deferred tax assets	$ 9,627	$ 9,113