CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 672,316	$ 25,305	$ 7,584
Other comprehensive income:
Unrealized gain on available-for-sale marketable securities, net of tax	30	944	396
Comprehensive income	$ 672,346	$ 26,249	$ 7,980