Note 9 - Goodwill and Core Deposit Intangible - Net - Core Deposit Intangible (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Balance—beginning of period	$ 11,374
Amortization expense	(1,021)	$ (724)	$ (339)
Balance—end of period	10,353	11,374
Core Deposits [Member]
Balance—beginning of period	11,374	7,338	0
Amortization expense	(1,021)	(724)	(339)
Balance—end of period	10,353	11,374	7,338
Core Deposits [Member] | First National Security Company Acquisition [Member]
Finite-lived iIntangible assets acquired	0	0	7,677
Core Deposits [Member] | Acquisition of MNB [Member]
Finite-lived iIntangible assets acquired	$ 0	$ 4,760	$ 0