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Loans and Allowance for Loan Losses - Activity for Loans Categorized as Troubled Debt Restructurings (Detail) (USD $) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012
Commercial and Industrial [Member] |  |  |  |
Schedule Of Troubled Debt Restructured Loans [Line Items] |  |  |  |
Beginning Balance | $ 2,266,000 | $ 4,665,000 | $ 2,721,000 | $ 4,553,000
Charge-Offs | 0 | (60,000) | (35,000) | (172,000)
Payments | (324,000) | (268,000) | (1,902,000) | (763,000)
Transfers to ORE | 0 | (45,000) | (74,000) | (96,000)
Net Additions/Deletions | 466,000 | 123,000 | 1,698,000 | 893,000
Ending Balance | 2,408,000 | 4,415,000 | 2,408,000 | 4,415,000
Commercial Vacant Land, Land Development, and Residential Construction [Member] |  |  |  |
Schedule Of Troubled Debt Restructured Loans [Line Items] |  |  |  |
Beginning Balance | 5,440,000 | 3,250,000 | 3,071,000 | 5,100,000
Charge-Offs | 0 | 0 | (725,000) | 0
Payments | (303,000) | (55,000) | (456,000) | (1,952,000)
Transfers to ORE | 0 | 0 | 0 | (351,000)
Net Additions/Deletions | 0 | 0 | 3,247,000 | 398,000
Ending Balance | 5,137,000 | 3,195,000 | 5,137,000 | 3,195,000
Commercial Real Estate - Owner Occupied [Member] |  |  |  |
Schedule Of Troubled Debt Restructured Loans [Line Items] |  |  |  |
Beginning Balance | 3,580,000 | 6,809,000 | 4,116,000 | 6,183,000
Charge-Offs | 0 | (12,000) | (70,000) | (426,000)
Payments | (271,000) | (2,750,000) | (1,310,000) | (3,317,000)
Transfers to ORE | 0 | 0 | (363,000) | 0
Net Additions/Deletions | (652,000) | 105,000 | 284,000 | 1,712,000
Ending Balance | 2,657,000 | 4,152,000 | 2,657,000 | 4,152,000
Commercial Real Estate - Non-Owner Occupied [Member] |  |  |  |
Schedule Of Troubled Debt Restructured Loans [Line Items] |  |  |  |
Beginning Balance | 34,424,000 | 16,881,000 | 37,672,000 | 12,037,000
Charge-Offs | 0 | (474,000) | (716,000) | (499,000)
Payments | (1,690,000) | (178,000) | (5,475,000) | (689,000)
Transfers to ORE | (350,000) | (579,000) | (1,153,000) | (579,000)
Net Additions/Deletions | 68,000 | 18,043,000 | 2,124,000 | 23,423,000
Ending Balance | 32,452,000 | 33,693,000 | 32,452,000 | 33,693,000
Commercial Real Estate - Multi-Family and Residential Rental [Member] |  |  |  |
Schedule Of Troubled Debt Restructured Loans [Line Items] |  |  |  |
Beginning Balance | 2,775,000 | 4,985,000 | 3,026,000 | 12,626,000
Charge-Offs | 0 | 0 | (15,000) | (2,180,000)
Payments | (295,000) | (263,000) | (530,000) | (5,914,000)
Transfers to ORE | 0 | 0 | 0 | 0
Net Additions/Deletions | 343,000 | 0 | 342,000 | 190,000
Ending Balance | 2,823,000 | 4,722,000 | 2,823,000 | 4,722,000
Retail Home Equity and Other [Member] |  |  |  |
Schedule Of Troubled Debt Restructured Loans [Line Items] |  |  |  |
Beginning Balance | 2,029,000 | 159,000 | 155,000 | 164,000
Charge-Offs | 0 | 0 | 0 | 0
Payments | (16,000) | (2,000) | (21,000) | (7,000)
Transfers to ORE | 0 | 0 | 0 | 0
Net Additions/Deletions | 0 | 0 | 1,879,000 | 0
Ending Balance | 2,013,000 | 157,000 | 2,013,000 | 157,000
Retail 1-4 Family Mortgages [Member] |  |  |  |
Schedule Of Troubled Debt Restructured Loans [Line Items] |  |  |  |
Beginning Balance | 0 | 0 | 0 | 0
Charge-Offs | 0 | 0 | 0 | 0
Payments | 0 | 0 | 0 | 0
Transfers to ORE | 0 | 0 | 0 | 0
Net Additions/Deletions | 0 | 0 | 0 | 0
Ending Balance | $ 0 | $ 0 | $ 0 | $ 0

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- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554 + Details
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