Note 13 - Income Taxes - Provisions (Benefits) for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal									$ 6,319	$ 403	$ 252
State									675	237	136
Total current									6,994	640	388
Deferred:
Federal									4,906	6,064	3,551
State									1,095	1,052	820
Deferred tax valuation allowance										(897)	(120)
Total deferred									6,001	6,219	4,251
Total, amount	$ 5,544	$ 2,072	$ 3,078	$ 2,300	$ 2,192	$ 2,384	$ 847	$ 1,436	$ 12,995	$ 6,859	$ 4,639