Note 5 - Loans (Details) - Aging of Loan Portfolio - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Type of Loans:
Loans past due	$ 78,466	$ 112,401
Non-accrual loans	52,130	70,163
Loans not past due	10,084,986	8,801,679
Loans	10,163,452	8,914,080
Financing Receivables, 30 to 59 Days Past Due [Member]
Type of Loans:
Loans past due	22,854	36,359
Financing Receivables, 60 to 89 Days Past Due [Member]
Type of Loans:
Loans past due	3,482	5,879
Commercial Portfolio Segment [Member]
Type of Loans:
Loans past due	12,133	19,816
Non-accrual loans	3,545	6,983
Loans not past due	2,304,730	2,362,677
Loans	2,316,863	2,382,493
Commercial Portfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Type of Loans:
Loans past due	8,367	11,595
Commercial Portfolio Segment [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member]
Type of Loans:
Loans past due	221	1,238
Real Estate Construction Portfolio Segment [Member]
Type of Loans:
Loans past due	23,591	21,379
Non-accrual loans	16,306	19,963
Loans not past due	417,952	277,275
Loans	441,543	298,654
Real Estate Construction Portfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Type of Loans:
Loans past due	7,285	1,416
Commercial Real Estate Portfolio Segment [Member]
Type of Loans:
Loans past due	29,697	57,169
Non-accrual loans	25,231	35,606
Loans not past due	5,271,521	4,429,274
Loans	5,301,218	4,486,443
Commercial Real Estate Portfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Type of Loans:
Loans past due	2,243	17,654
Commercial Real Estate Portfolio Segment [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member]
Type of Loans:
Loans past due	2,223	3,909
Residential Mortgage Loans [Member]
Type of Loans:
Loans past due	13,045	13,977
Non-accrual loans	7,048	7,611
Loans not past due	2,088,290	1,728,961
Loans	2,101,335	1,742,938
Residential Mortgage Loans [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Type of Loans:
Loans past due	4,959	5,634
Residential Mortgage Loans [Member] \| Financing Receivables, 60 to 89 Days Past Due [Member]
Type of Loans:
Loans past due	1,038	732
Consumer Portfolio Segment [Member]
Type of Loans:
Loans past due		60
Loans not past due	2,493	3,492
Loans	$ 2,493	3,552
Consumer Portfolio Segment [Member] \| Financing Receivables, 30 to 59 Days Past Due [Member]
Type of Loans:
Loans past due		$ 60

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- Definition

Financing receivables that are current.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953401-111524

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Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5111-111524

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Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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