Note 4 - Loans and Allowance for Loan Losses - Recorded Investment in Loans, Excluding Loans Acquired (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Balance, end of period	$ 5,632,890	$ 4,919,355
Commercial Portfolio Segment [Member]
Balance, end of period	789,903	648,679
Commercial Real Estate Portfolio Segment [Member]
Balance, end of period	3,028,079	2,204,992
Consumer Portfolio Segment [Member]
Balance, end of period	488,563	385,668
Unallocated Financing Receivables [Member]
Balance, end of period	20,662	7,115
Loans, Excluding Acquired Loans [Member]
Loans individually evaluated for impairment	43,696	18,190
Loans collectively evaluated for impairment	4,283,511	3,228,264
Balance, end of period	4,327,207	3,246,454
Loans, Excluding Acquired Loans [Member] \| Commercial Portfolio Segment [Member]
Loans individually evaluated for impairment	11,522	2,252
Loans collectively evaluated for impairment	778,381	646,427
Balance, end of period	789,903	648,679
Loans, Excluding Acquired Loans [Member] \| Commercial Real Estate Portfolio Segment [Member]
Loans individually evaluated for impairment	30,001	15,017
Loans collectively evaluated for impairment	2,998,078	2,189,975
Balance, end of period	3,028,079	2,204,992
Loans, Excluding Acquired Loans [Member] \| Consumer Portfolio Segment [Member]
Loans individually evaluated for impairment	373	479
Loans collectively evaluated for impairment	184,218	176,809
Balance, end of period	184,591	177,288
Loans, Excluding Acquired Loans [Member] \| Unallocated Financing Receivables [Member]
Loans individually evaluated for impairment	1,800	442
Loans collectively evaluated for impairment	322,834	215,053
Balance, end of period	$ 324,634	$ 215,495

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

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=66008989&loc=SL6953423-111524

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- Definition

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

+ References

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- Definition

Amount before allowance and after 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. 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=65884687&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5074-111524

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