Note 7 - Fair Value Measurements - Effect of Cash Flow Hedge Accounting on the Company's Statement of Operations (Details) - Interest Expense [Member] - Designated as Hedging Instrument [Member] - Cash Flow Hedging [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Hedged interest payments	$ (7,698)	$ (6,370)
Interest Rate Swap [Member]
Gain on interest rate swaps	$ 706	$ 444