Note 4 - Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Jan. 31, 2019	Jan. 31, 2018
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 150,990,000	$ 144,389,000	$ 139,413,000	$ 147,023,000
Interest Rate Swap [Member]
Derivative, Gain (Loss) on Derivative, Net, Total	(91,000)	$ 117,000
Reported Value Measurement [Member]
Cash and Cash Equivalents, at Carrying Value, Ending Balance	$ 31,700,000		$ 31,600,000