Note 3 - Fair Value Measurements - Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Jan. 31, 2019
Short-term investments		$ 1,200
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Liability related to the interest rate swap
Short-term investments		1,200
Asset related to the interest rate swap
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] | Fair Value, Recurring [Member]
Cash and cash equivalents	107,319	105,205
Fair Value, Inputs, Level 1 [Member] | Certificates of Deposit [Member] | Fair Value, Recurring [Member]
Cash and cash equivalents	14,917	11,578
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Liability related to the interest rate swap	(232)
Short-term investments
Asset related to the interest rate swap		136
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member] | Fair Value, Recurring [Member]
Cash and cash equivalents
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member] | Fair Value, Recurring [Member]
Cash and cash equivalents