Note 4 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017	Feb. 01, 2018	Jan. 31, 2018	Jan. 31, 2017
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 139,528,000	$ 149,202,000	$ 139,528,000	$ 149,202,000	$ 147,023,000	$ 147,023,000	$ 145,082,000
Interest Rate Swap [Member]
Derivative, Gain (Loss) on Derivative, Net, Total	35,000	$ (16,000)	152,000	$ (3,000)
Reported Value Measurement [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 32,000,000		$ 32,000,000			$ 32,000,000