Note 5 - Loans - Allowance for Loan Losses by Portfolio Segment and Based on Impairment Method (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Loans individually evaluated for impairment, allowance	$ 2,796	$ 7,749
Loans individually evaluated for impairment, balance	115,074	133,810
Loans collectively evaluated for impairment, allowance	116,170	131,214
Loans collectively evaluated for impairment, balance	11,086,201	10,029,642
Loans, allowance	118,966	138,963
Loans	11,201,275	10,163,452
Commercial Portfolio Segment [Member]
Loans individually evaluated for impairment, allowance	1,827	530
Loans individually evaluated for impairment, balance	27,761	13,568
Loans collectively evaluated for impairment, allowance	47,376	55,669
Loans collectively evaluated for impairment, balance	2,220,426	2,303,295
Loans, allowance	49,203	56,199
Loans	2,248,187	2,316,863
Real Estate Construction Portfolio Segment [Member]
Loans individually evaluated for impairment, allowance
Loans individually evaluated for impairment, balance	5,458	22,002
Loans collectively evaluated for impairment, allowance	23,268	22,170
Loans collectively evaluated for impairment, balance	542,630	419,541
Loans, allowance	23,268	22,170
Loans	548,088	441,543
Commercial Real Estate Portfolio Segment [Member]
Loans individually evaluated for impairment, allowance	573	6,792
Loans individually evaluated for impairment, balance	64,470	81,776
Loans collectively evaluated for impairment, allowance	34,291	42,648
Loans collectively evaluated for impairment, balance	5,720,778	5,219,442
Loans, allowance	34,864	49,440
Loans	5,785,248	5,301,218
Residential Mortgage and Equity Lines Portfolio Segment [Member]
Loans individually evaluated for impairment, allowance	396	427
Loans individually evaluated for impairment, balance	17,385	16,464
Loans collectively evaluated for impairment, allowance	11,224	10,718
Loans collectively evaluated for impairment, balance	2,598,374	2,084,871
Loans, allowance	11,620	11,145
Loans	2,615,759	2,101,335
Consumer Portfolio Segment [Member]
Loans individually evaluated for impairment, allowance
Loans individually evaluated for impairment, balance
Loans collectively evaluated for impairment, allowance	11	9
Loans collectively evaluated for impairment, balance	3,993	2,493
Loans, allowance	11	9
Loans	$ 3,993	$ 2,493

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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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 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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