Note 4 - Fair Value Measurements and Derivative Financial Instruments - Financial Liabilities Measured at Fair Value on Recurring Basis (Details) - Interest Rate Swap [Member] - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Other assets	$ 686	$ 515
Fair Value, Inputs, Level 1 [Member]
Other assets
Fair Value, Inputs, Level 2 [Member]
Other assets	686	515
Fair Value, Inputs, Level 3 [Member]
Other assets