Note 5 - Loans (Details) - Allowance for Loan Losses by Portfolio Segment and Based on Impairment Method (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	$ 11,798	$ 13,284
Loans individually evaluated for impairment, balance	174,519	200,780
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	149,622	160,605
Loans collectively evaluated for impairment, balance	8,739,561	7,883,783
Loans, allowance	161,420	173,889
Loans	8,914,080	8,084,563
Commercial Loans [Member]
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	1,263	2,519
Loans individually evaluated for impairment, balance	23,489	31,968
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	46,238	62,584
Loans collectively evaluated for impairment, balance	2,359,004	2,266,756
Loans, allowance	47,501	65,103
Loans	2,382,493	2,298,724
Real Estate Construction Loans [Member]
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	1,077	3,460
Loans individually evaluated for impairment, balance	25,728	34,420
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	26,575	8,539
Loans collectively evaluated for impairment, balance	272,926	187,281
Loans, allowance	27,652	11,999
Loans	298,654	221,701
Commercial Mortgage Loans [Member]
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	8,993	6,584
Loans individually evaluated for impairment, balance	109,194	114,544
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	65,680	78,169
Loans collectively evaluated for impairment, balance	4,377,249	3,908,507
Loans, allowance	74,673	84,753
Loans	4,486,443	4,023,051
Residential Mortgage And Equity Lines Member
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	465	721
Loans individually evaluated for impairment, balance	16,108	19,848
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	11,113	11,284
Loans collectively evaluated for impairment, balance	1,726,830	1,506,684
Loans, allowance	11,578	12,005
Loans	1,742,938	1,526,532
Consumer and Other [Member]
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	16	29
Loans collectively evaluated for impairment, balance	3,552	14,555
Loans, allowance	16	29
Loans	$ 3,552	$ 14,555

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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- Definition

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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-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

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-Subparagraph (SX 210.9-03.7(d))

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-Name Staff Accounting Bulletin (SAB)

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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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