Note 5 - Loans - Accruing Troubled Debt Restructurings (Details) - Accruing Troubled Debt Restructuring [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accruing TDRs	$ 65,393	$ 81,680	$ 104,356	$ 117,597
Payment Deferral [Member]
Accruing TDRs	39,054	30,200
Contractual Interest Rate Reduction [Member]
Accruing TDRs	6,750	7,044
Rate Reduction and Payment Deferral [Member]
Accruing TDRs	19,589	44,436
Commercial Portfolio Segment [Member]
Accruing TDRs	12,052	10,024
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	7,971	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	4,081	1,726
Commercial Real Estate Portfolio Segment [Member]
Accruing TDRs	44,392	56,546
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	25,979	16,701
Commercial Real Estate Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Accruing TDRs	5,961	6,045
Commercial Real Estate Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	12,452	33,800
Real Estate Construction Portfolio Segment [Member]
Accruing TDRs		5,696
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
Residential Portfolio Segment [Member]
Accruing TDRs	8,949	9,414
Residential Portfolio Segment [Member] | Payment Deferral [Member]
Accruing TDRs	5,104	5,201
Residential Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Accruing TDRs	789	999
Residential Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Accruing TDRs	$ 3,056	$ 3,214