Note 6 - Stock Repurchase Program (Details Textual) - USD ($) $ in Thousands	3 Months Ended									17 Months Ended
	Apr. 30, 2018		Jan. 31, 2018	[2]	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	[3]	Apr. 30, 2018
Stock Repurchase Program, Authorized Amount	$ 750									$ 750
Treasury Stock, Shares, Acquired	178,526	[1]	536,058		8,607		80,426	49,920		853,537

[1] 178,526 shares of common stock purchased were purchased through a private transaction

[2] 536,058 shares of common stock purchased were purchased through a private transaction

[3] 49,920 shares of common stock purchased were purchased through a private transaction