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Securities - Summary of Investments in an Unrealized Loss Position that were Temporarily Impaired (Detail) - USD ($) $ in Thousands | Jun. 30, 2017 | Dec. 31, 2016
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Securities available for sale: |  |
Less than 12 months - Fair value | $ 44,894 | $ 66,073
Less than 12 months - Unrealized (loss) | (546) | (1,429)
12 months or more - Fair value | 4,964 | 5,499
12 months or more - Unrealized (loss) | (151) | (208)
Fair Value | 49,858 | 71,572
Unrealized (Loss) | (697) | (1,637)
Securities held to maturity: |  |
Less than 12 months - Fair value | 19,451 | 48,980
Less than 12 months - Unrealized (loss) | (210) | (708)
12 months or more - Fair value | 0 | 0
12 months or more - Unrealized (loss) | 0 | 0
Fair Value | 19,451 | 48,980
Unrealized (Loss) | (210) | (708)
Total securities, Less than 12 months - Fair value | 64,345 | 115,053
Total securities, Less than 12 months - Unrealized (loss) | (756) | (2,137)
Total securities, 12 months or more - Fair value | 4,964 | 5,499
Total securities, 12 months or more - Unrealized (loss) | (151) | (208)
Total securities, Total fair value | 69,309 | 120,552
Total unrealized (loss) | (907) | (2,345)
U.S. agency and mortgage-backed securities |  |
Securities available for sale: |  |
Less than 12 months - Fair value | 42,325 | 60,943
Less than 12 months - Unrealized (loss) | (493) | (1,249)
12 months or more - Fair value | 4,964 | 5,499
12 months or more - Unrealized (loss) | (151) | (208)
Fair Value | 47,289 | 66,442
Unrealized (Loss) | (644) | (1,457)
Securities held to maturity: |  |
Less than 12 months - Fair value | 17,961 | 34,770
Less than 12 months - Unrealized (loss) | (200) | (483)
12 months or more - Fair value | 0 | 0
12 months or more - Unrealized (loss) | 0 | 0
Fair Value | 17,961 | 34,770
Unrealized (Loss) | (200) | (483)
Obligations of states and political subdivisions |  |
Securities available for sale: |  |
Less than 12 months - Fair value | 2,569 | 5,130
Less than 12 months - Unrealized (loss) | (53) | (180)
12 months or more - Fair value | 0 | 0
12 months or more - Unrealized (loss) | 0 | 0
Fair Value | 2,569 | 5,130
Unrealized (Loss) | (53) | (180)
Securities held to maturity: |  |
Less than 12 months - Fair value |  | 12,724
Less than 12 months - Unrealized (loss) |  | (211)
12 months or more - Fair value |  | 0
12 months or more - Unrealized (loss) |  | 0
Fair Value |  | 12,724
Unrealized (Loss) |  | (211)
Corporate debt securities |  |
Securities held to maturity: |  |
Less than 12 months - Fair value | 1,490 | 1,486
Less than 12 months - Unrealized (loss) | (10) | (14)
12 months or more - Fair value | 0 | 0
12 months or more - Unrealized (loss) | 0 | 0
Fair Value | 1,490 | 1,486
Unrealized (Loss) | $ (10) | $ (14)

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