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
	Apr. 30, 2021	Apr. 30, 2020
Net income (loss)	$ 1,832	$ (410)
Dividends declared	(1,454)	(1,431)
Undistributed net income (loss)	378	(1,841)
Dividends declared	1,454	1,431
Common Class A [Member]
Net income (loss)	1,580	(353)
Dividends declared	(1,254)	(1,232)
Undistributed net income (loss)	326	(1,585)
Dividends declared	$ 1,254	$ 1,232
Weighted average shares of common stock outstanding—basic (in shares)	17,379	17,112
Weighted average potential shares of common stock (in shares)	1,067	0
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	18,446	17,112
Basic net loss per common share (in dollars per share)	$ 0.09	$ (0.02)
Diluted net loss per common share (in dollars per share)	0.09	(0.02)
Basic net (loss) income per share (in dollars per share)	0.09	(0.02)
Diluted net (loss) income per share (in dollars per share)	$ 0.09	$ (0.02)
Common Class B [Member]
Net income (loss)	$ 252	$ (57)
Dividends declared	(200)	(199)
Undistributed net income (loss)	52	(256)
Dividends declared	$ 200	$ 199
Weighted average shares of common stock outstanding—basic (in shares)	3,330	3,321
Weighted average potential shares of common stock (in shares)	79	0
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	3,409	3,321
Basic net loss per common share (in dollars per share)	$ 0.08	$ (0.02)
Diluted net loss per common share (in dollars per share)	0.07	(0.02)
Basic net (loss) income per share (in dollars per share)	0.08	(0.02)
Diluted net (loss) income per share (in dollars per share)	$ 0.07	$ (0.02)