Note 7 - Loans (Details) - Accruing Troubled Debt Restructurings (Accruing Troubled Debt Restructuring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 100,393	$ 104,356
Payment Deferral [Member] | Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	13,108	11,572
Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	17,430	20,543
Payment Deferral [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,233	3,316
Payment Deferral [Member] | Real Estate Construction Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		5,765
Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	35,771	41,196
Rate Reduction [Member] | Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	1,520
Rate Reduction [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	6,101	26,694
Rate Reduction [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	1,008
Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	8,629	26,694
Rate Reduction and Payment Deferral [Member] | Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	2,094	4,934
Rate Reduction and Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	50,861	26,351
Rate Reduction and Payment Deferral [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	3,038	4,771
Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	55,993	36,056
Rate Reduction and Forgiveness of Principal [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		410
Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		410
Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	16,722	16,506
Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	74,392	73,588
Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	9,279	8,497
Real Estate Construction Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		$ 5,765