Note 8 - Fair Value Measurement - Cash and Cash Equivalents (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Total assets	$ 65,233	$ 70,483
Interest rate swap	3,514	7,606
Total liabilities	3,514	7,606
Fair Value, Inputs, Level 1 [Member]
Total assets	65,233	70,483
Interest rate swap	0	0
Total liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Total assets	0	0
Interest rate swap	3,514	7,606
Total liabilities	3,514	7,606
Fair Value, Inputs, Level 3 [Member]
Total assets	0	0
Interest rate swap	0	0
Total liabilities	0	0
Money Market Funds [Member]
Cash equivalents	65,233	70,483
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Cash equivalents	65,233	70,483
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Cash equivalents	0	0
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Cash equivalents	$ 0	$ 0