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Securities - Summary of Amortized Costs and Fair Values of Securities Available for Sale (Detail) - USD ($) $ in Thousands | Dec. 31, 2015 | Dec. 31, 2014
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Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |
Available-for-sale Securities, Debt and Equity, Amortized Cost Basis, Total | $ 105,851 | $ 83,494
Securities available for sale, Gross Unrealized Gains | 601 | 704
Securities available for sale, Gross Unrealized (Losses) | (893) | (906)
Securities available for sale, Fair Value | 105,559 | 83,292
Securities held to maturity, Amortized Cost | 66,519 |
Securities held to maturity, Gross Unrealized Gains | 264 |
Securities held to maturity, Gross Unrealized (Losses) | (345) |
Securities held to maturity, Fair Value | 66,438 | 0
Total securities, Amortized Cost | 172,370 |
Total securities, Gross Unrealized Gains | 865 |
Total securities, Gross Unrealized (Losses) | (1,238) |
Total securities, Fair Value | 171,997 |
U.S. Agency and Mortgage-Backed Securities [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |
Available-for-sale Securities, Debt and Equity, Amortized Cost Basis, Total | 89,919 | 67,462
Securities available for sale, Gross Unrealized Gains | 261 | 374
Securities available for sale, Gross Unrealized (Losses) | (843) | (807)
Securities available for sale, Fair Value | 89,337 | 67,029
Securities held to maturity, Amortized Cost | 49,662 |
Securities held to maturity, Gross Unrealized Gains | 36 |
Securities held to maturity, Gross Unrealized (Losses) | (326) |
Securities held to maturity, Fair Value | 49,372 |
Obligations of States and Political Subdivisions [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |
Available-for-sale Securities, Debt and Equity, Amortized Cost Basis, Total | 15,931 | 16,031
Securities available for sale, Gross Unrealized Gains | 333 | 325
Securities available for sale, Gross Unrealized (Losses) | (50) | (99)
Securities available for sale, Fair Value | 16,214 | 16,257
Securities held to maturity, Amortized Cost | 15,357 |
Securities held to maturity, Gross Unrealized Gains | 228 |
Securities held to maturity, Gross Unrealized (Losses) | (19) |
Securities held to maturity, Fair Value | 15,566 |
Corporate Equity Securities [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |
Available-for-sale Securities, Debt and Equity, Amortized Cost Basis, Total | 1 | 1
Securities available for sale, Gross Unrealized Gains | 7 | 5
Securities available for sale, Fair Value | 8 | $ 6
Corporate Debt Securities [Member] |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |
Securities held to maturity, Amortized Cost | 1,500 |
Securities held to maturity, Fair Value | $ 1,500 |

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