Note 2 - Computation of Net 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, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Dividends declared	$ (1,344)	$ (1,326)	$ (2,675)	$ (2,642)
Net (loss) income per share
Dividends declared	1,344	1,326	2,675	2,642
Undistributed net loss	(2,505)	(358)	(6,407)	(4,466)
Net (loss) income	(1,161)	968	(3,732)	(1,824)
Common Class A [Member]
Dividends declared	$ (1,151)	$ (1,134)	$ (2,290)	$ (2,257)
Net (loss) income per share
Basic net (loss) income per common share (in dollars per share)	$ (0.06)	$ 0.05	$ (0.20)	$ (0.10)
Diluted net (loss) income per common share (in dollars per share)	$ (0.06)	$ 0.05	$ (0.20)	$ (0.10)
Dividends declared	$ 1,151	$ 1,134	$ 2,290	$ 2,257
Undistributed net loss	(2,145)	(306)	(5,483)	(3,813)
Net (loss) income	$ (994)	$ 828	$ (3,193)	$ (1,556)
Weighted average shares of common stock outstanding—basic (in shares)	15,914	15,694	15,863	15,644
Weighted average potential shares of common stock (in shares)		586
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	15,914	16,280	15,863	15,644
Common Class B [Member]
Dividends declared	$ (193)	$ (192)	$ (385)	$ (385)
Net (loss) income per share
Basic net (loss) income per common share (in dollars per share)	$ (0.05)	$ 0.04	$ (0.17)	$ (0.08)
Diluted net (loss) income per common share (in dollars per share)	$ (0.05)	$ 0.04	$ (0.17)	$ (0.08)
Dividends declared	$ 193	$ 192	$ 385	$ 385
Undistributed net loss	(360)	(52)	(924)	(653)
Net (loss) income	$ (167)	$ 140	$ (539)	$ (268)
Weighted average shares of common stock outstanding—basic (in shares)	3,212	3,205	3,211	3,204
Weighted average potential shares of common stock (in shares)		70
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	3,212	3,275	3,211	3,204