Note 5 - Loans (Details) - Accruing Troubled Debt Restructurings (Accruing Troubled Debt Restructuring [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 104,356,000	$ 117,597,000
Interest Deferral [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	436,000
Interest Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	436,000
Principal Deferral [Member] | Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	11,572,000	9,112,000
Principal Deferral [Member] | Real Estate Construction Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,765,000
Principal Deferral [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	20,107,000	11,333,000
Principal Deferral [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	3,316,000	1,564,000
Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	40,760,000	22,009,000
Rate Reduction [Member] | Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		2,916,000
Rate Reduction [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	26,694,000	9,389,000
Rate Reduction [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		1,024,000
Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	26,694,000	13,329,000
Rate Reduction and Forgiveness of Principal [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	410,000
Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	410,000
Rate Reduction and Payment Deferral [Member] | Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	4,934,000	2,708,000
Rate Reduction and Payment Deferral [Member] | Real Estate Construction Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs		5,834,000
Rate Reduction and Payment Deferral [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	26,351,000	70,200,000
Rate Reduction and Payment Deferral [Member] | Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	4,771,000	3,517,000
Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	36,056,000	82,259,000
Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	16,506,000	14,736,000
Real Estate Construction Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,765,000	5,834,000
Commercial Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	73,588,000	90,922,000
Residential Mortgage Loans [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 8,497,000	$ 6,105,000