Note 7 - Loans (Details) - Accruing Troubled Debt Restructurings - Accruing Troubled Debt Restructuring [Member] - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 100,011	$ 100,393	$ 104,356	$ 111,136	$ 118,922	$ 117,597
Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	46,939		41,196
Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	8,583		26,694
Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	44,489		36,056
Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs			410
Commercial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	15,839		16,506
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	12,386		11,572
Commercial Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	1,496
Commercial Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	1,957		4,934
Real Estate Construction Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,730		5,765
Real Estate Construction Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs			5,765
Real Estate Construction Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,730
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	69,602		73,588
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	29,465		20,543
Commercial Real Estate Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	6,082		26,694
Commercial Real Estate Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	34,055		26,351
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	8,840		8,497
Residential Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	5,088		3,316
Residential Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	1,005
Residential Portfolio Segment [Member] | Rate Reduction and Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 2,747		4,771
Residential Portfolio Segment [Member] | Rate Reduction and Forgiveness of Principal [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs			$ 410