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Securities - Summary of Amortized Costs and Fair Values of Securities (Detail) - USD ($) $ in Thousands | Sep. 30, 2016 | Dec. 31, 2015
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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 | $ 86,881 | $ 105,851 |
Securities available for sale, Gross Unrealized Gains | 1,504 | 601 |
Securities available for sale, Gross Unrealized (Losses) | (62) | (893) |
Securities available for sale, Fair Value | 88,323 | 105,559 | [1]
Securities held to maturity, Amortized Cost | 55,263 | 66,519 |
Securities held to maturity, Gross Unrealized Gains | 1,042 | 264 |
Securities held to maturity, Gross Unrealized (Losses) |  | (345) |
Securities held to maturity, Fair Value | 56,305 | 66,438 | [1]
Total securities, Amortized Cost | 142,144 | 172,370 |
Total securities, Gross Unrealized Gains | 2,546 | 865 |
Total securities, Gross Unrealized (Losses) | (62) | (1,238) |
Total securities, Fair Value | 144,628 | 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 | 74,732 | 89,919 |
Securities available for sale, Gross Unrealized Gains | 1,092 | 261 |
Securities available for sale, Gross Unrealized (Losses) | (62) | (843) |
Securities available for sale, Fair Value | 75,762 | 89,337 |
Securities held to maturity, Amortized Cost | 39,118 | 49,662 |
Securities held to maturity, Gross Unrealized Gains | 487 | 36 |
Securities held to maturity, Gross Unrealized (Losses) |  | (326) |
Securities held to maturity, Fair Value | 39,605 | 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 | 12,148 | 15,931 |
Securities available for sale, Gross Unrealized Gains | 402 | 333 |
Securities available for sale, Gross Unrealized (Losses) |  | (50) |
Securities available for sale, Fair Value | 12,550 | 16,214 |
Securities held to maturity, Amortized Cost | 14,645 | 15,357 |
Securities held to maturity, Gross Unrealized Gains | 531 | 228 |
Securities held to maturity, Gross Unrealized (Losses) |  | (19) |
Securities held to maturity, Fair Value | 15,176 | 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 | 10 | 7 |
Securities available for sale, Fair Value | 11 | 8 |
Corporate Debt Securities [Member] |  |  |
Schedule Of Available For Sale And Held To Maturity Securities [Line Items] |  |  |
Securities held to maturity, Amortized Cost | 1,500 | 1,500 |
Securities held to maturity, Gross Unrealized Gains | 24 |  |
Securities held to maturity, Fair Value | $ 1,524 | $ 1,500 |
[1] | Derived from audited consolidated financial statements.

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