Note 7 - Loans - Non-accrual Troubled Debt Restructurings (Details) - Non-accruing Troubled Debt Restructuring [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	$ 3,477		$ 1,033
Commercial Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	90		90
Commercial Portfolio Segment [Member]
Accruing TDRs	3,567		1,123
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	1,508		1,544
Commercial Real Estate Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	15,260		20,362
Commercial Real Estate Portfolio Segment [Member]
Accruing TDRs	16,768		21,906
Real Estate Construction Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs			9,981
Real Estate Construction Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs			5,825
Real Estate Construction Portfolio Segment [Member]
Accruing TDRs			15,806
Residential Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	364		388
Residential Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	171		700
Residential Portfolio Segment [Member]
Accruing TDRs	535		1,088
Payment Deferral [Member]
Accruing TDRs	5,349		12,946
Rate Reduction and Payment Deferral [Member]
Accruing TDRs	15,521		26,977
Accruing TDRs	$ 20,870	$ 25,442	$ 39,923	$ 41,806	$ 42,595	$ 41,618