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, 2018	Apr. 30, 2017
Net income (loss)	$ 1,397	$ (2,571)
Dividends declared	(1,359)	(1,331)
Undistributed net income (loss)	38	(3,902)
Net (loss) income per share
Dividends declared	1,359	1,331
Undistributed net income (loss)	38	(3,902)
Net (loss) income	1,397	(2,571)
Common Class A [Member]
Net income (loss)	1,196	(2,199)
Dividends declared	(1,164)	(1,138)
Undistributed net income (loss)	32	(3,337)
Net (loss) income per share
Dividends declared	1,164	1,138
Undistributed net income (loss)	32	(3,337)
Net (loss) income	$ 1,196	$ (2,199)
Weighted average shares of common stock outstanding—basic (in shares)	16,076	15,809
Weighted average potential shares of common stock (in shares)	1,750
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	17,826	15,809
Basic net (loss) income per common share (in dollars per share)	$ 0.07	$ (0.14)
Diluted net (loss) income per common share (in dollars per share)	$ 0.07	$ (0.14)
Common Class B [Member]
Net income (loss)	$ 201	$ (372)
Dividends declared	(195)	(193)
Undistributed net income (loss)	6	(565)
Net (loss) income per share
Dividends declared	195	193
Undistributed net income (loss)	6	(565)
Net (loss) income	$ 201	$ (372)
Weighted average shares of common stock outstanding—basic (in shares)	3,232	3,210
Weighted average potential shares of common stock (in shares)	182
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	3,414	3,210
Basic net (loss) income per common share (in dollars per share)	$ 0.06	$ (0.12)
Diluted net (loss) income per common share (in dollars per share)	$ 0.06	$ (0.12)