Note 4 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	Jan. 31, 2019	Jan. 31, 2018
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 141,768,000	$ 139,528,000	$ 141,768,000	$ 139,528,000	$ 139,413,000	$ 147,023,000
Interest Rate Swap [Member]
Derivative, Gain (Loss) on Derivative, Net, Total	(160,000)	$ 35,000	251,000	$ 152,000
Reported Value Measurement [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 35,000,000		$ 35,000,000		$ 31,600,000