Note 7 - Loans - Accruing Troubled Debt Restructurings (Details) - 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	$ 22,019		$ 8,298
Commercial Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Accruing TDRs
Commercial Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	1,360		1,726
Commercial Portfolio Segment [Member]
Accruing TDRs	23,379		10,024
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	26,835		16,701
Commercial Real Estate Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Accruing TDRs	5,986		6,045
Commercial Real Estate Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	20,690		33,800
Commercial Real Estate Portfolio Segment [Member]
Accruing TDRs	53,511		56,546
Real Estate Construction Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs
Real Estate Construction Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Accruing TDRs
Real Estate Construction Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs			5,696
Real Estate Construction Portfolio Segment [Member]
Accruing TDRs			5,696
Residential Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	5,048		5,201
Residential Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Accruing TDRs	989		999
Residential Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	3,628		3,214
Residential Portfolio Segment [Member]
Accruing TDRs	9,665		9,414
Payment Deferral [Member]
Accruing TDRs	53,902		30,200
Contractual Interest Rate Reduction [Member]
Accruing TDRs	6,975		7,044
Rate Reduction and Payment Deferral [Member]
Accruing TDRs	25,678		44,436
Accruing TDRs	$ 86,555	$ 74,708	$ 81,680	$ 89,881	$ 100,011	$ 104,355