Note 7 - Fair Value Measurements - Schedule of Reconciliation of Carrying Value of Company's Interest Rate Swaps (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in fair value credited to interest expense			$ (820)
Interest Rate Swap [Member]
Beginning balance	$ (100)	$ (79)
Reclassified from other assets and other long-term liabilities to accumulated other comprehensive loss	471	(170)
Change in fair value credited to interest expense	144	149
Ending balance	$ 515	$ (100)	$ (79)