Note 3 - Computation of Net (Loss) Income 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, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Net (loss) income	$ (13,250)	$ 1,113	$ (16,484)	$ 2,510
Dividends declared	(1,387)	(1,372)	(2,761)	(2,731)
Undistributed net loss	(14,637)	(259)	(19,245)	(221)
Net (loss) income per share
Dividends declared	1,387	1,372	2,761	2,731
Undistributed net loss	(14,637)	(259)	(19,245)	(221)
Net (loss) income	(13,250)	1,113	(16,484)	2,510
Common Class A [Member]
Net (loss) income	(11,379)	954	(14,152)	2,150
Dividends declared	(1,191)	(1,176)	(2,370)	(2,340)
Undistributed net loss	(12,570)	(222)	(16,522)	(190)
Net (loss) income per share
Dividends declared	1,191	1,176	2,370	2,340
Undistributed net loss	(12,570)	(222)	(16,522)	(190)
Net (loss) income	$ (11,379)	$ 954	$ (14,152)	$ 2,150
Weighted average shares of common stock outstanding—basic (in shares)	16,465	16,266	16,417	16,173
Weighted average potential shares of common stock (in shares)		1,661		1,713
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	16,465	17,927	16,417	17,886
Basic net (loss) income per common share (in dollars per share)	$ (0.69)	$ 0.06	$ (0.86)	$ 0.13
Diluted net (loss) income per common share (in dollars per share)	$ (0.69)	$ 0.05	$ (0.86)	$ 0.12
Common Class B [Member]
Net (loss) income	$ (1,871)	$ 159	$ (2,332)	$ 360
Dividends declared	(196)	(196)	(391)	(391)
Undistributed net loss	(2,067)	(37)	(2,723)	(31)
Net (loss) income per share
Dividends declared	196	196	391	391
Undistributed net loss	(2,067)	(37)	(2,723)	(31)
Net (loss) income	$ (1,871)	$ 159	$ (2,332)	$ 360
Weighted average shares of common stock outstanding—basic (in shares)	3,264	3,263	3,264	3,248
Weighted average potential shares of common stock (in shares)		171		177
Weighted average shares of common stock and potential common shares outstanding—diluted (in shares)	3,264	3,434	3,264	3,425
Basic net (loss) income per common share (in dollars per share)	$ (0.57)	$ 0.05	$ (0.71)	$ 0.11
Diluted net (loss) income per common share (in dollars per share)	$ (0.57)	$ 0.05	$ (0.71)	$ 0.11