Note 7 - Loans (Details) - Allowance for Loan Losses by Portfolio Segment and Based on Impairment Method (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	$ 13,814	$ 13,284
Loans individually evaluated for impairment, balance	188,347	200,780
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	155,384	160,605
Loans collectively evaluated for impairment, balance	8,669,907	7,883,783
Loans, allowance	169,198	173,889
Loans	8,858,254	8,084,563
Commercial Loans [Member]
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	2,730	2,519
Loans individually evaluated for impairment, balance	25,749	31,968
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	53,566	62,584
Loans collectively evaluated for impairment, balance	2,424,369	2,266,756
Loans, allowance	56,296	65,103
Loans	2,450,118	2,298,724
Real Estate Construction Loans [Member]
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	2,604	3,460
Loans individually evaluated for impairment, balance	31,510	34,420
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	32,099	8,539
Loans collectively evaluated for impairment, balance	269,949	187,281
Loans, allowance	34,703	11,999
Loans	301,459	221,701
Commercial Mortgage Loans [Member]
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	7,999	6,584
Loans individually evaluated for impairment, balance	115,559	114,544
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	58,740	78,169
Loans collectively evaluated for impairment, balance	4,298,508	3,908,507
Loans, allowance	66,739	84,753
Loans	4,414,067	4,023,051
Residential Mortgage And Equity Lines Member
Loans individually evaluated for impairment
Loans individually evaluated for impairment, allowance	481	721
Loans individually evaluated for impairment, balance	15,529	19,848
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	10,962	11,284
Loans collectively evaluated for impairment, balance	1,673,405	1,506,684
Loans, allowance	11,443	12,005
Loans	1,688,934	1,526,532
Installment And Other Loans [Member]
Loans collectively evaluated for impairment
Loans collectively evaluated for impairment, allowance	17	29
Loans collectively evaluated for impairment, balance	3,676	14,555
Loans, allowance	17	29
Loans	$ 3,676	$ 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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- Definition

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

+ References

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- Definition

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

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

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-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

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