Note 4 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Jan. 31, 2020
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 143,392,000		$ 143,392,000		$ 136,717,000
Interest Rate Swap [Member]
Derivative, Gain (Loss) on Derivative, Net, Total	70,000	$ (101,000)	(149,000)	$ (352,000)
Reported Value Measurement [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 18,400,000		$ 18,400,000		$ 14,500,000