CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 25,305	$ 7,584	$ (3,822)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale marketable securities, net of tax	944	396	(531)
Comprehensive income (loss)	$ 26,249	$ 7,980	$ (4,353)