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Securities - Summary of Investments in an Unrealized Loss Position that were Temporarily Impaired (Detail) - USD ($) $ in Thousands | Dec. 31, 2015 | Dec. 31, 2014
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Schedule of Available-for-sale Securities [Line Items] |  |
Securities available for sale, Less than 12 months - Fair Value | $ 52,580 | $ 9,392
Securities available for sale, 12 months or more - Fair Value | 14,462 | 35,368
Securities available for sale, Total - Fair Value | 67,042 | 44,760
Securities available for sale, Less than 12 months - Unrealized (Loss) | (479) | (61)
Securities available for sale, 12 months or more - Unrealized (Loss) | (414) | (845)
Total Unrealized (Loss) | (893) | (906)
Securities held to maturity, Less than 12 months - Fair Value | 35,843 |
Securities held to maturity, 12 months or more - Fair Value | 0 |
Securities held to maturity, Total - Fair Value | 35,843 |
Securities held to maturity, Less than 12 months - Unrealized (Loss) | (345) |
Securities held to maturity, 12 months or more - Unrealized (Loss) | 0 |
Total Unrealized (Loss) | (345) |
Total securities, Less than 12 months - Fair Value | 88,423 |
Total securities, 12 months or more - Fair Value | 14,462 |
Total securities, Total - Fair Value | 102,885 |
Total securities, Less than 12 months - Unrealized (Loss) | (824) |
Total securities, 12 months or more - Unrealized (Loss) | (414) |
Total Unrealized (Loss) | (1,238) |
U.S. Agency and Mortgage-Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Securities available for sale, Less than 12 months - Fair Value | 50,185 | 8,677
Securities available for sale, 12 months or more - Fair Value | 13,409 | 32,527
Securities available for sale, Total - Fair Value | 63,594 | 41,204
Securities available for sale, Less than 12 months - Unrealized (Loss) | (464) | (60)
Securities available for sale, 12 months or more - Unrealized (Loss) | (379) | (747)
Total Unrealized (Loss) | (843) | (807)
Securities held to maturity, Less than 12 months - Fair Value | 32,791 |
Securities held to maturity, 12 months or more - Fair Value | 0 |
Securities held to maturity, Total - Fair Value | 32,791 |
Securities held to maturity, Less than 12 months - Unrealized (Loss) | (326) |
Securities held to maturity, 12 months or more - Unrealized (Loss) | 0 |
Total Unrealized (Loss) | (326) |
Obligations of States and Political Subdivisions [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Securities available for sale, Less than 12 months - Fair Value | 2,395 | 715
Securities available for sale, 12 months or more - Fair Value | 1,053 | 2,841
Securities available for sale, Total - Fair Value | 3,448 | 3,556
Securities available for sale, Less than 12 months - Unrealized (Loss) | (15) | (1)
Securities available for sale, 12 months or more - Unrealized (Loss) | (35) | (98)
Total Unrealized (Loss) | (50) | $ (99)
Securities held to maturity, Less than 12 months - Fair Value | 3,052 |
Securities held to maturity, 12 months or more - Fair Value | 0 |
Securities held to maturity, Total - Fair Value | 3,052 |
Securities held to maturity, Less than 12 months - Unrealized (Loss) | (19) |
Securities held to maturity, 12 months or more - Unrealized (Loss) | 0 |
Total Unrealized (Loss) | $ (19) |

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