Note 4 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019	Jan. 31, 2020
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 140,707,000		$ 140,707,000		$ 136,717,000
Interest Rate Swap [Member]
Derivative, Gain (Loss) on Derivative, Net, Total	32,000	$ (160,000)	(219,000)	$ (251,000)
Reported Value Measurement [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 18,500,000		$ 18,500,000		$ 14,500,000