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, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Net (loss) income	$ 410	$ 125	$ (13,250)	$ (3,234)	$ 4,936	$ 2,982	$ 1,113	$ 1,397	$ (15,949)	$ 10,428	$ (9,065)
Less: dividends declared									(5,617)	(5,479)	(5,367)
Undistributed net (loss) income									(21,566)	4,949	(14,432)
Dividends declared									5,617	5,479	5,367
Allocation of undistributed net (loss) income									(21,566)	4,949	(14,432)
Common Class A [Member]
Net (loss) income									(13,692)	8,939	(7,762)
Less: dividends declared									(4,827)	(4,696)	(4,596)
Undistributed net (loss) income									(18,519)	4,243	(12,358)
Dividends declared									4,827	4,696	4,596
Allocation of undistributed net (loss) income									$ (18,519)	$ 4,243	$ (12,358)
Weighted average shares of common stock outstanding—basic (in shares)									16,709	16,267	15,942
Weighted average potential shares of common stock (in shares)										1,585
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)									16,709	17,852	15,942
Basic net (loss) income per common share (in dollars per share)	$ 0.02	$ 0.01	$ (0.69)	$ (0.17)	$ 0.26	$ 0.16	$ 0.06	$ 0.07	$ (0.82)	$ 0.55	$ (0.49)
Diluted net (loss) income per common share (in dollars per share)	0.02	0.01	(0.69)	(0.17)	0.24	0.14	0.05	0.07	$ (0.82)	$ 0.50	$ (0.49)
Common Class B [Member]
Net (loss) income									$ (2,257)	$ 1,489	$ (1,303)
Less: dividends declared									(790)	(783)	(771)
Undistributed net (loss) income									(3,047)	706	(2,074)
Dividends declared									790	783	771
Allocation of undistributed net (loss) income									$ (3,047)	$ 706	$ (2,074)
Weighted average shares of common stock outstanding—basic (in shares)									3,289	3,256	3,213
Weighted average potential shares of common stock (in shares)										166
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)									3,289	3,422	3,213
Basic net (loss) income per common share (in dollars per share)	0.02	0.01	(0.57)	(0.14)	0.22	0.13	0.05	0.06	$ (0.69)	$ 0.46	$ (0.41)
Diluted net (loss) income per common share (in dollars per share)	$ 0.02	$ 0.01	$ (0.57)	$ (0.14)	$ 0.21	$ 0.12	$ 0.05	$ 0.06	$ (0.69)	$ 0.44	$ (0.41)