Note 16 - Disclosures About Fair Value of Financial Instruments - Estimated Fair Values and Related Carrying Amounts of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Held-to-maturity securities	$ 465,960	$ 713,371
Reported Value Measurement [Member]
Cash and cash equivalents	285,659	252,262
Interest bearing balances due from banks - time	4,563	14,107
Held-to-maturity securities	462,096	705,373
Mortgage loans held for sale	27,788	30,265
Interest receivable	27,788	25,793
Federal funds purchased and securities sold under agreements to repurchase	115,029	99,398
Other borrowings	273,159	162,289
Subordinated debentures	60,397	60,570
Interest payable	1,668	1,800
Reported Value Measurement [Member] \| Non-Interest Bearing Transaction Accounts [Member]
Deposits	1,491,676	1,280,234
Reported Value Measurement [Member] \| Interest Bearing Transaction Accounts and Savings Deposits [Member]
Deposits	3,956,483	3,485,845
Reported Value Measurement [Member] \| Time Deposits [Member]
Deposits	1,287,060	1,320,017
Reported Value Measurement [Member] \| Legacy Loans [Member]
Legacy loans (net of allowance)	4,290,921	3,215,103
Reported Value Measurement [Member] \| Acquired Loans [Member]
Legacy loans (net of allowance)	1,305,683	1,672,901
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	285,659	252,262
Interest bearing balances due from banks - time	4,563	14,105
Held-to-maturity securities	465,960	713,371
Mortgage loans held for sale	27,788	30,265
Interest receivable	27,788	25,793
Federal funds purchased and securities sold under agreements to repurchase	115,029	99,398
Other borrowings	292,367	168,254
Subordinated debentures	55,318	55,954
Interest payable	1,668	1,800
Estimate of Fair Value Measurement [Member] \| Non-Interest Bearing Transaction Accounts [Member]
Deposits	1,491,676	1,280,234
Estimate of Fair Value Measurement [Member] \| Interest Bearing Transaction Accounts and Savings Deposits [Member]
Deposits	3,956,483	3,485,845
Estimate of Fair Value Measurement [Member] \| Time Deposits [Member]
Deposits	1,278,339	1,315,254
Estimate of Fair Value Measurement [Member] \| Legacy Loans [Member]
Legacy loans (net of allowance)	4,305,165	3,204,153
Estimate of Fair Value Measurement [Member] \| Acquired Loans [Member]
Legacy loans (net of allowance)	1,310,017	1,667,204
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	285,659	252,262
Interest bearing balances due from banks - time
Held-to-maturity securities
Mortgage loans held for sale
Interest receivable
Federal funds purchased and securities sold under agreements to repurchase
Other borrowings
Subordinated debentures
Interest payable
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Non-Interest Bearing Transaction Accounts [Member]
Deposits
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Interest Bearing Transaction Accounts and Savings Deposits [Member]
Deposits
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Time Deposits [Member]
Deposits
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Legacy Loans [Member]
Legacy loans (net of allowance)
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Acquired Loans [Member]
Legacy loans (net of allowance)
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents
Interest bearing balances due from banks - time	4,563	14,105
Held-to-maturity securities	465,960	713,371
Mortgage loans held for sale
Interest receivable	27,788	25,793
Federal funds purchased and securities sold under agreements to repurchase	115,029	99,398
Other borrowings	292,367	168,254
Subordinated debentures	55,318	55,954
Interest payable	1,668	1,800
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Non-Interest Bearing Transaction Accounts [Member]
Deposits	1,491,676	1,280,234
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Interest Bearing Transaction Accounts and Savings Deposits [Member]
Deposits	3,956,483	3,485,845
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Time Deposits [Member]
Deposits
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Legacy Loans [Member]
Legacy loans (net of allowance)
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Acquired Loans [Member]
Legacy loans (net of allowance)
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents
Interest bearing balances due from banks - time
Held-to-maturity securities
Mortgage loans held for sale	27,788	30,265
Interest receivable
Federal funds purchased and securities sold under agreements to repurchase
Other borrowings
Subordinated debentures
Interest payable
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Non-Interest Bearing Transaction Accounts [Member]
Deposits
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Interest Bearing Transaction Accounts and Savings Deposits [Member]
Deposits
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Time Deposits [Member]
Deposits	1,278,339	1,315,254
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Legacy Loans [Member]
Legacy loans (net of allowance)	4,305,165	3,204,153
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Acquired Loans [Member]
Legacy loans (net of allowance)	$ 1,310,017	$ 1,667,204

Represents the fair value portion of interest bearing balances due from banks - time.

No definition available.

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- Definition

Fair value portion of interest payable on debt, including, but not limited to, trade payables.

+ References

No definition available.

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- Definition

The fair value of accrued interest receivable.

+ References

No definition available.

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- Definition

The fair value portion of the aggregate of other miscellaneous borrowings owed by the reporting entity as of the balance sheet date.

+ References

No definition available.

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

+ Details

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- Definition

Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of short term borrowing where a bank borrows, at the federal funds rate, from another bank and securities that an entity sells and agrees to repurchase at a specified date for a specified price.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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Period Type:	instant

- Definition

Fair value of investments in debt securities classified as held-to-maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27232-111563

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Balance Type:	debit
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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Glossary Loan
-URI http://asc.fasb.org/extlink&oid=6517073

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of mortgage loans held-for-sale.

+ References

No definition available.

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