Note 8 - Loans - Troubled Debt Restructuring (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
No. of Contracts	6	14	32	21
Pre-Modification Outstanding Recorded Investment	$ 5,373	$ 23,479	$ 28,051	$ 52,638
Post-Modification Outstanding Recorded Investment	5,373	23,174	28,051	52,333
Charge-offs		305		305
Special Reserve	$ 2,483	$ 678	$ 2,636	$ 683
Commercial Portfolio Segment [Member]
No. of Contracts	3	8	21	13
Pre-Modification Outstanding Recorded Investment	$ 4,621	$ 18,873	$ 12,212	$ 19,543
Post-Modification Outstanding Recorded Investment	4,621	18,873	12,212	19,543
Charge-offs
Special Reserve	$ 2,467	$ 636	$ 2,493	$ 641
Commercial Real Estate Portfolio Segment [Member]
No. of Contracts	1	5	7	5
Pre-Modification Outstanding Recorded Investment	$ 339	$ 4,123	$ 14,626	$ 4,123
Post-Modification Outstanding Recorded Investment	339	3,818	14,626	3,818
Charge-offs		305		305
Special Reserve		$ 10	$ 119	$ 10
Real Estate Construction Portfolio Segment [Member]
No. of Contracts				2
Pre-Modification Outstanding Recorded Investment				$ 28,489
Post-Modification Outstanding Recorded Investment				28,489
Charge-offs
Special Reserve
Residential Portfolio Segment [Member]
No. of Contracts	2	1	4	1
Pre-Modification Outstanding Recorded Investment	$ 413	$ 483	$ 1,213	$ 483
Post-Modification Outstanding Recorded Investment	413	483	1,213	483
Charge-offs
Special Reserve	$ 16	$ 32	$ 24	$ 32