Loans and Allowance - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale	$ 1,943	$ 7,235
Loans	4,321,715	3,924,865
Other commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	167,990	35,018
Increase in loans	132,972
Real estate loans - Commercial and farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,695,703	$ 1,672,661
Percentage of troubled debt restructured loans	47.00%

Financing Receivable, Modifications, Post-Modification, Loans as Percentage of Troubled Debt Restructured Loans

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- Definition

Loans and Leases Receivable, Period Increase (Decrease)

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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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

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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- Definition

Amount, after allowance for bad debt, of loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

+ References

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