Note 5 - Loans (Details) - Components of Loans in Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Type of Loans:
Gross loans	$ 8,914,080	$ 8,084,563
Allowance for loan losses	(161,420)	(173,889)
Unamortized deferred loan fees	(12,392)	(13,487)
Total loans and leases, net	8,740,268us-gaap_LoansReceivableNet	7,897,187us-gaap_LoansReceivableNet
Loans held for sale	973us-gaap_LoansReceivableHeldForSaleNet
Commercial Loans [Member]
Type of Loans:
Gross loans	2,382,493	2,298,724
Real Estate Construction Loans [Member]
Type of Loans:
Gross loans	298,654	221,701
Commercial Mortgage Loans [Member]
Type of Loans:
Gross loans	4,486,443	4,023,051
Residential Mortgage Loans [Member]
Type of Loans:
Gross loans	1,570,059	1,355,255
Equity Lines [Member]
Type of Loans:
Gross loans	172,879	171,277
Installment And Other Loans [Member]
Type of Loans:
Gross loans	$ 3,552	$ 14,555

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount classified as loans attributable to disposal group held for sale or disposed of. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. Excludes loans and leases covered under loss sharing agreements.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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