Note 7 - Loans (Details) - Accruing Troubled Debt Restructurings - Accruing Troubled Debt Restructuring [Member] - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 90,172
Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	38,993	$ 30,200
Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	7,021	7,044
Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	44,158	81,680
Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		44,436
Commercial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	9,041
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	7,446	8,298
Commercial Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	1,595	10,024
Commercial Portfolio Segment [Member] | Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		1,726
Real Estate Construction Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,679
Real Estate Construction Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,679	5,696
Real Estate Construction Portfolio Segment [Member] | Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		5,696
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	65,607
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	26,393	16,701
Commercial Real Estate Portfolio Segment [Member] | Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	6,025	6,045
Commercial Real Estate Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	33,189	56,546
Commercial Real Estate Portfolio Segment [Member] | Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		33,800
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	9,845
Residential Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,154	5,201
Residential Portfolio Segment [Member] | Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	996	999
Residential Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 3,695	9,414
Residential Portfolio Segment [Member] | Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		$ 3,214