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Loans and Allowance for Loan Losses - Loans Modified as Troubled Debt Restructurings (Detail) (USD $) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2013 Contract | Sep. 30, 2012 Contract | Sep. 30, 2013 Contract | Sep. 30, 2012 Contract
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 5 | 6 | 14 | 17
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | $ 1,070,000 | $ 18,175,000 | $ 9,233,000 | $ 24,871,000
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 1,070,000 | 18,170,000 | 9,233,000 | 24,863,000
Commercial and industrial [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 1 | 1 | 2 | 6
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 553,000 | 133,000 | 613,000 | 850,000
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 553,000 | 128,000 | 613,000 | 843,000
Vacant land, land development and residential construction [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 0 | 0 | 2 | 0
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 0 | 0 | 3,247,000 | 0
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 0 | 0 | 3,247,000 | 0
Real estate - owner occupied [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 0 | 0 | 3 | 5
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 0 | 0 | 909,000 | 1,588,000
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 0 | 0 | 909,000 | 1,587,000
Real estate - non-owner occupied [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 2 | 5 | 4 | 6
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 171,000 | 18,042,000 | 2,239,000 | 22,433,000
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 171,000 | 18,042,000 | 2,239,000 | 22,433,000
Real estate - multi-family and residential rental [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 2 | 0 | 2 | 0
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 346,000 | 0 | 346,000 | 0
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 346,000 | 0 | 346,000 | 0
Commercial Loans [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 5 | 6 | 13 | 17
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 1,070,000 | 18,175,000 | 7,354,000 | 24,871,000
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 1,070,000 | 18,170,000 | 7,354,000 | 24,863,000
Home equity and other [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 0 | 0 | 0 | 0
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 0 | 0 | 0 | 0
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 0 | 0 | 0 | 0
1 - 4 family mortgages [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 0 | 0 | 1 | 0
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 0 | 0 | 1,879,000 | 0
Financing Receivable Modification, Post-Modification Recorded Principal Balance | 0 | 0 | 1,879,000 | 0
Retail Loans [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Financing Receivable Modification, Number of Contracts | 0 | 0 | 1 | 0
Financing Receivable Modification, Pre-Modification Recorded Principal Balance | 0 | 0 | 1,879,000 | 0
Financing Receivable Modification, Post-Modification Recorded Principal Balance | $ 0 | $ 0 | $ 1,879,000 | $ 0

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