Note 1 - Summary of Business and Significant Accounting Policies - Basic and Diluted Net (Loss) Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Net (loss) income	$ (5,172)	$ (161)	$ (1,161)	$ (2,571)	$ (15,159)	$ 1,533	$ 968	$ (2,792)	$ (9,065)	$ (15,450)	$ 8,912
Less: dividends declared									(5,367)	(5,301)	(5,235)
Undistributed net (loss) income									(14,432)	(20,751)	3,677
Dividends declared									5,367	5,301	5,235
Allocation of undistributed net (loss) income									(14,432)	(20,751)	3,677
Common Class A [Member]
Net (loss) income									(7,762)	(13,211)	7,606
Less: dividends declared									(4,596)	(4,531)	(4,466)
Undistributed net (loss) income									(12,358)	(17,742)	3,140
Dividends declared									4,596	4,531	4,466
Allocation of undistributed net (loss) income									$ (12,358)	$ (17,742)	$ 3,140
Weighted average shares of common stock outstanding—basic (in shares)									15,942	15,715	15,466
Weighted average potential shares of common stock (in shares)											758
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)									15,942	15,715	16,224
Basic net (loss) income per common share (in dollars per share)	$ (0.28)	$ (0.01)	$ (0.06)	$ (0.14)	$ (0.82)	$ 0.08	$ 0.05	$ (0.15)	$ (0.49)	$ (0.84)	$ 0.49
Diluted net (loss) income per common share (in dollars per share)	(0.28)	(0.01)	(0.06)	(0.14)	(0.82)	0.08	0.05	(0.15)	$ (0.49)	$ (0.84)	$ 0.47
Common Class B [Member]
Net (loss) income									$ (1,303)	$ (2,239)	$ 1,306
Less: dividends declared									(771)	(770)	(769)
Undistributed net (loss) income									(2,074)	(3,009)	537
Dividends declared									771	770	769
Allocation of undistributed net (loss) income									$ (2,074)	$ (3,009)	$ 537
Weighted average shares of common stock outstanding—basic (in shares)									3,213	3,206	3,201
Weighted average potential shares of common stock (in shares)											82
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)									3,213	3,206	3,283
Basic net (loss) income per common share (in dollars per share)	(0.23)	(0.01)	(0.05)	(0.12)	(0.68)	0.07	0.04	(0.13)	$ (0.41)	$ (0.70)	$ 0.41
Diluted net (loss) income per common share (in dollars per share)	$ (0.23)	$ (0.01)	$ (0.05)	$ (0.12)	$ (0.68)	$ 0.07	$ 0.04	$ (0.13)	$ (0.41)	$ (0.70)	$ 0.40