Note 4 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Jan. 31, 2020	Jan. 31, 2019
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 140,154,000	$ 150,990,000	$ 136,717,000	$ 139,413,000
Interest Rate Swap [Member]
Derivative, Gain (Loss) on Derivative, Net, Total	(251,000)	$ (91,000)
Reported Value Measurement [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 17,700,000		$ 14,500,000