Employee Benefits and Stock-based Compensation - Classification of Stock-based Compensation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Stock-based compensation:
Total stock-based compensation	$ 87,801	$ 70,134	$ 66,871
Cost of revenue [Member]
Stock-based compensation:
Total stock-based compensation	1,489	1,328	1,184
Research and development [Member]
Stock-based compensation:
Total stock-based compensation	54,787	42,903	41,842
Selling, general and administrative [Member]
Stock-based compensation:
Total stock-based compensation	$ 31,525	$ 25,903	$ 23,845