Note 4 - Fair Value Measurements - Financial Assets and Liabilities (Details) - USD ($) $ in Thousands		Oct. 31, 2018	Jan. 31, 2018
Asset related to the interest rate swap		$ 385	$ 187
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Money market mutual funds	[1]	110,893	115,416
Asset related to the interest rate swap	[2]
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Money market mutual funds	[1]
Asset related to the interest rate swap	[2]	$ 385	$ 187

[1] Money market mutual funds are recorded at fair value based upon quoted market prices.

[2] The asset related to the interest rate swap is recorded at fair value based upon a valuation model that uses relevant observable market inputs at quoted intervals, such as forward yield curves.