Note 3 - Computation of Net Income (Loss) Per Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Net (loss) income	$ (6,322)	$ 60	$ (4,490)	$ (350)
Dividends declared	(1,469)	(1,448)	(2,923)	(2,879)
Undistributed net loss	(7,791)	(1,388)	(7,413)	(3,229)
Dividends declared	1,469	1,448	2,923	2,879
Allocation of undistributed net loss	(7,791)	(1,388)	(7,413)	(3,229)
Common Class A [Member]
Net (loss) income	(5,460)	52	(3,880)	(301)
Dividends declared	(1,269)	(1,249)	(2,523)	(2,481)
Undistributed net loss	(6,729)	(1,197)	(6,403)	(2,782)
Dividends declared	1,269	1,249	2,523	2,481
Allocation of undistributed net loss	$ (6,729)	$ (1,197)	$ (6,403)	$ (2,782)
Weighted average shares of common stock outstanding—basic (in shares)	17,533	17,245	17,457	17,179
Weighted average potential shares of common stock (in shares)	0	568	0	0
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	17,533	17,813	17,457	17,179
Basic net loss per common share (in dollars per share)	$ (0.31)	$ 0.00	$ (0.22)	$ (0.02)
Diluted net loss per common share (in dollars per share)	(0.31)	0.00	(0.22)	(0.02)
Basic net (loss) income per share (in dollars per share)	(0.31)	0.00	(0.22)	(0.02)
Diluted net (loss) income per share (in dollars per share)	$ (0.31)	$ 0.00	$ (0.22)	$ (0.02)
Common Class B [Member]
Net (loss) income	$ (862)	$ 8	$ (610)	$ (49)
Dividends declared	(200)	(199)	(400)	(398)
Undistributed net loss	(1,062)	(191)	(1,010)	(447)
Dividends declared	200	199	400	398
Allocation of undistributed net loss	$ (1,062)	$ (191)	$ (1,010)	$ (447)
Weighted average shares of common stock outstanding—basic (in shares)	3,339	3,321	3,335	3,321
Weighted average potential shares of common stock (in shares)	0	68	0	0
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	3,339	3,389	3,335	3,321
Basic net loss per common share (in dollars per share)	$ (0.26)	$ 0.00	$ (0.18)	$ (0.01)
Diluted net loss per common share (in dollars per share)	(0.26)	0.00	(0.18)	(0.01)
Basic net (loss) income per share (in dollars per share)	(0.26)	0.00	(0.18)	(0.01)
Diluted net (loss) income per share (in dollars per share)	$ (0.26)	$ 0.00	$ (0.18)	$ (0.01)