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Securities - Summary of Securities with Unrealized Losses, Segregated by Duration of Unrealized Loss (Detail) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2013 | Dec. 31, 2012
Schedule Of Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position [Line Items] |  |
Held-to-maturity Securities, Less than Twelve Months, Fair Value | $ 1 | $ 1,443
Held-to-maturity Securities, Less than 12 Months, unrealized losses |  | 8
Held-to-maturity Securities, Twelve Months or Longer, Fair Value | 1,329 | 5
Held-to-maturity Securities, 12 Months or Longer, unrealized losses | 7 |
Held-to-maturity Securities, Fair Value, Total | 1,330 | 1,448
Held-to-maturity Securities, unrealized losses, Total | 7 | 8
Available-for-sale Securities, Less than Twelve Months, Fair Value | 111,957 | 50,816
Available-for-sale Securities, Less than 12 Months, unrealized losses | 548 | 86
Available-for-sale Securities, Twelve Months or Longer, Fair Value | 150,188 | 126,756
Available-for-sale Securities, 12 Months or Longer, unrealized losses | 259 | 113
Available-for-sale Securities, Fair Value, Total | 262,145 | 177,572
Available-for-sale Securities, unrealized losses, Total | 807 | 199
U.S. treasuries [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position [Line Items] |  |
Available-for-sale Securities, Less than Twelve Months, Fair Value | 29,861 |
Available-for-sale Securities, Less than 12 Months, unrealized losses | 85 |
Available-for-sale Securities, Fair Value, Total | 29,861 |
Available-for-sale Securities, unrealized losses, Total | 85 |
U.S. Federal agencies [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position [Line Items] |  |
Held-to-maturity Securities, Less than Twelve Months, Fair Value | 1 | 1
Held-to-maturity Securities, Twelve Months or Longer, Fair Value | 1 | 5
Held-to-maturity Securities, Fair Value, Total | 2 | 6
Available-for-sale Securities, Less than Twelve Months, Fair Value | 79,477 | 45,905
Available-for-sale Securities, Less than 12 Months, unrealized losses | 250 | 54
Available-for-sale Securities, Twelve Months or Longer, Fair Value | 150,188 | 125,868
Available-for-sale Securities, 12 Months or Longer, unrealized losses | 259 | 111
Available-for-sale Securities, Fair Value, Total | 229,665 | 171,773
Available-for-sale Securities, unrealized losses, Total | 509 | 165
States and political subdivisions [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position [Line Items] |  |
Held-to-maturity Securities, Less than Twelve Months, Fair Value |  | 1,442
Held-to-maturity Securities, Less than 12 Months, unrealized losses |  | 8
Held-to-maturity Securities, Twelve Months or Longer, Fair Value | 1,328 |
Held-to-maturity Securities, 12 Months or Longer, unrealized losses | 7 |
Held-to-maturity Securities, Fair Value, Total | 1,328 | 1,442
Held-to-maturity Securities, unrealized losses, Total | 7 | 8
Available-for-sale Securities, Less than Twelve Months, Fair Value | 2,459 | 1,545
Available-for-sale Securities, Less than 12 Months, unrealized losses | 72 | 18
Available-for-sale Securities, Twelve Months or Longer, Fair Value |  | 888
Available-for-sale Securities, 12 Months or Longer, unrealized losses |  | 2
Available-for-sale Securities, Fair Value, Total | 2,459 | 2,433
Available-for-sale Securities, unrealized losses, Total | 72 | 20
Other [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities Continuous Unrealized Loss Position [Line Items] |  |
Available-for-sale Securities, Less than Twelve Months, Fair Value | 160 | 3,366
Available-for-sale Securities, Less than 12 Months, unrealized losses | 141 | 14
Available-for-sale Securities, Fair Value, Total | 160 | 3,366
Available-for-sale Securities, unrealized losses, Total | $ 141 | $ 14

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- Definition Amount of accumulated pre-tax unrealized loss on investments in available-for-sale securities that have been in a loss position for twelve months or longer. + References No definition available. + Details
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- Definition Amount of accumulated pre-tax unrealized loss on investments on securities classified as available-for-sale securities recognized in AOCI. + References No definition available. + Details
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- Definition Amount of accumulated pre-tax unrealized loss on investments in available-for-sale securities that have been in a loss position for less than twelve months. + References No definition available. + Details
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- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
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- Definition Amount of unrealized loss on investments in held-to-maturity securities that have been in a loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
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