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Loans and Loans Held for Sale - Restructured Loans for Periods Stated (Detail) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2015 USD ($) SecurityLoan | Jun. 30, 2014 USD ($) SecurityLoan | Jun. 30, 2015 USD ($) SecurityLoan | Jun. 30, 2014 USD ($) SecurityLoan
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  | 7 |  | 7 |  | 27 |  | 19 |
Pre-Modification Outstanding Recorded Investment |  | $ 796,000 | [1] | $ 233,000 | [1] | $ 5,408,000 | [2] | $ 2,042,000 | [1]
Post-Modification Outstanding Recorded Investment |  | $ 796,000 | [1] | 229,000 | [1] | 5,381,000 | [2] | 2,019,000 | [1]
Total Difference in Recorded Investment |  |  |  | $ (4,000) |  | $ (27,000) |  | $ (23,000) |
Principal Forgiveness [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  | 1 | [3] |  |  | 1 |  | 0 |
Pre-Modification Outstanding Recorded Investment |  | $ 400,000 | [1],[3] |  |  | $ 400,000 | [2] | $ 0 | [2]
Post-Modification Outstanding Recorded Investment |  | $ 400,000 | [1],[3] |  |  | 400,000 | [2] | 0 | [2]
Total Difference in Recorded Investment |  |  |  |  |  | $ 0 |  | $ 0 |
Principal Forgiveness [Member] | Commercial and Industrial [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  | 1 |  |  |  | 1 |  | 0 |
Pre-Modification Outstanding Recorded Investment |  | $ 400,000 | [1] |  |  | $ 400,000 | [2] | $ 0 | [2]
Post-Modification Outstanding Recorded Investment |  | $ 400,000 | [1] |  |  | $ 400,000 | [2] | $ 0 | [2]
Principal Deferral [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  | 1 |  | 9 |  | 1 |
Pre-Modification Outstanding Recorded Investment |  |  |  | $ 129,000 | [1] | $ 3,616,000 | [2] | $ 129,000 | [2]
Post-Modification Outstanding Recorded Investment |  |  |  | 127,000 | [1] | 3,615,000 | [2] | 127,000 | [2]
Total Difference in Recorded Investment |  |  |  | $ (2,000) |  | $ (1,000) |  | $ (2,000) |
Principal Deferral [Member] | Commercial Real Estate [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  | 1 |  | 2 |  | 1 |
Pre-Modification Outstanding Recorded Investment |  |  |  | $ 129,000 | [1] | $ 2,851,000 | [2] | $ 129,000 | [2]
Post-Modification Outstanding Recorded Investment |  |  |  | 127,000 | [1] | $ 2,851,000 | [2] | 127,000 | [2]
Total Difference in Recorded Investment |  |  |  | $ (2,000) |  |  |  | (2,000) |
Principal Deferral [Member] | Commercial and Industrial [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  |  |  | 6 |  |  |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 661,000 |  | 0 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 661,000 |  | 0 |
Principal Deferral [Member] | Construction Loans [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  |  |  | 1 |  |  |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 104,000 |  | 0 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  | 103,000 |  | $ 0 |
Total Difference in Recorded Investment |  |  |  |  |  | $ (1,000) |  |  |
Chapter 7 Bankruptcy [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  | 4 |  | 6 |  | 13 | [4] | 17 | [4]
Pre-Modification Outstanding Recorded Investment |  | $ 171,000 | [1] | $ 104,000 | [1] | $ 316,000 | [2],[4] | $ 894,000 | [2],[4]
Post-Modification Outstanding Recorded Investment |  | $ 171,000 | [1] | 102,000 | [1] | 305,000 | [2],[4] | 873,000 | [2],[4]
Total Difference in Recorded Investment |  |  |  | $ (2,000) |  | $ (11,000) | [4] | $ (21,000) | [4]
Chapter 7 Bankruptcy [Member] | Commercial and Industrial [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan | [4] |  |  |  |  | 1 |  | 1 |
Pre-Modification Outstanding Recorded Investment | [2],[4] |  |  |  |  | $ 3,000 |  | $ 287,000 |
Post-Modification Outstanding Recorded Investment | [2],[4] |  |  |  |  | 1,000 |  | 286,000 |
Total Difference in Recorded Investment | [4] |  |  |  |  | $ (2,000) |  | $ (1,000) |
Chapter 7 Bankruptcy [Member] | Residential Mortgage [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  | 1 |  |  |  | 5 | [4]
Pre-Modification Outstanding Recorded Investment |  |  |  | $ 52,000 | [1] |  |  | $ 329,000 | [2],[4]
Post-Modification Outstanding Recorded Investment |  |  |  | $ 52,000 | [1] |  |  | 327,000 | [2],[4]
Total Difference in Recorded Investment | [4] |  |  |  |  |  |  | $ (2,000) |
Chapter 7 Bankruptcy [Member] | Home Equity [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  | 4 |  | 4 |  | 12 | [4] | 10 | [4]
Pre-Modification Outstanding Recorded Investment |  | $ 171,000 | [1] | $ 43,000 | [1] | $ 313,000 | [2],[4] | $ 269,000 | [2],[4]
Post-Modification Outstanding Recorded Investment |  | $ 171,000 | [1] | 41,000 | [1] | 304,000 | [2],[4] | 251,000 | [2],[4]
Total Difference in Recorded Investment |  |  |  | $ (2,000) |  | $ (9,000) | [4] | $ (18,000) | [4]
Chapter 7 Bankruptcy [Member] | Consumer Borrower [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  | 1 |  |  |  | 1 | [4]
Pre-Modification Outstanding Recorded Investment |  |  |  | $ 9,000 | [1] |  |  | $ 9,000 | [2],[4]
Post-Modification Outstanding Recorded Investment |  |  |  | $ 9,000 | [1] |  |  | 9,000 | [2],[4]
Interest Rate Reduction and Maturity Date Extension [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  |  |  | 2 |  |  |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 225,000 |  | 0 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 225,000 |  | $ 0 |
Interest Rate Reduction and Maturity Date Extension [Member] | Residential Mortgage [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  | 2 |  |  |  |  |  |  |
Pre-Modification Outstanding Recorded Investment |  | $ 225,000 |  |  |  |  |  |  |
Post-Modification Outstanding Recorded Investment |  | $ 225,000 |  |  |  |  |  |  |
Maturity Date Extension [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  |  |  | 2 |  | 1 |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 851,000 |  | $ 1,019,000 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  | 836,000 |  | 1,019,000 |
Total Difference in Recorded Investment |  |  |  |  |  | $ (15,000) |  |  |
Maturity Date Extension [Member] | Commercial and Industrial [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  |  |  | 1 |  |  |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 780,000 |  | 0 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  | 765,000 |  | $ 0 |
Total Difference in Recorded Investment |  |  |  |  |  | $ (15,000) |  |  |
Maturity Date Extension [Member] | Construction Loans [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans |  |  |  |  |  |  |  | 1 |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  |  |  | $ 1,019,000 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  |  |  | 1,019,000 |
Maturity Date Extension [Member] | Residential Mortgage [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  |  |  | 2 |  |  |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 225,000 |  | 0 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 225,000 |  | 0 |
Maturity Date Extension [Member] | Home Equity [Member] |  |  |  |  |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |  |  |  |  |
Number of Loans | SecurityLoan |  |  |  |  |  | 1 |  |  |
Pre-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 71,000 |  | 0 |
Post-Modification Outstanding Recorded Investment | [2] |  |  |  |  | $ 71,000 |  | $ 0 |
[1] | Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.
[2] | Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.
[3] | Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.
[4] | Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.

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