Note 13 - Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Balances at	$ 113,559	$ 112,449	$ 78,845
Other Comprehensive Income (Loss)	957	(1,541)	(146)
Reclassify Stranded Tax Effects
Balances at	179,935	113,559	112,449
AOCI Attributable to Parent [Member]
Balances at	(2,330)	(789)	(643)
Other Comprehensive Income (Loss) Before Reclassifications - Net of Tax	937	(1,694)
Reclassification Adjustment for Gains (Losses) Realized - Net of Tax	20	153
Other Comprehensive Income (Loss)	957	(1,541)	(146)
Reclassify Stranded Tax Effects	(271)
Balances at	$ (1,644)	$ (2,330)	$ (789)