Unaudited Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	APIC	Accumulated Deficit	Treasury stock
Beginning balance (in shares) at Jan. 31, 2020		36,610,763
Beginning balance at Jan. 31, 2020	$ 101,865	$ 366	$ 386,383	$ (284,485)	$ (399)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(6,112)			(6,112)
Stock-based compensation expense	2,872		2,872
Exercise of stock options and vesting of restricted stock (in shares)		988,678
Exercise of stock options and vesting of restricted stock units	1,736	$ 10	1,726
Treasury stock from vesting of restricted stock units - satisfaction of tax withholdings	(447)				(447)
Ending balance (in shares) at Apr. 30, 2020		37,599,441
Ending balance at Apr. 30, 2020	99,914	$ 376	390,981	(290,597)	(846)
Beginning balance (in shares) at Jan. 31, 2021		44,880,883
Beginning balance at Jan. 31, 2021	263,306	$ 449	579,599	(311,777)	(4,965)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(10,974)			(10,974)
Stock-based compensation expense	$ 5,774		5,774
Exercise of stock options and vesting of restricted stock (in shares)	167,067	214,346
Exercise of stock options and vesting of restricted stock units	$ 500	$ 2	498
Treasury stock from vesting of restricted stock units - satisfaction of tax withholdings	(1,145)				(1,145)
Issuance of common stock in public offering, net of issuance costs (in shares)		5,175,000
Issuance of common stock in public offering, net of issuance costs	245,813	$ 52	245,761
Ending balance (in shares) at Apr. 30, 2021		50,270,229
Ending balance at Apr. 30, 2021	$ 503,274	$ 503	$ 831,632	$ (322,751)	$ (6,110)