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Securities - Additional Information (Detail) | 12 Months Ended
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Dec. 31, 2015 USD ($) Securities Obligation | Dec. 31, 2014 USD ($) Securities Obligation
Amortized Cost and Fair Value Debt Securities [Abstract] |  |
Number of U.S. agency and mortgage-backed securities | Securities | 52 | 29
Number of obligations of state and political subdivisions in an unrealized loss position | Obligation | 13 | 7
Percentage of investment portfolio | 100.00% | 100.00%
Weighted-average period of re-pricing of portfolio | 4 years 7 months 6 days | 3 years 10 months 24 days
Proceeds from maturities, calls, principal payments and sales of securities available for sale | $ 17,725,000 | $ 35,781,000
Gross realized gains on securities available for sale | 0 | 787,000
Gross realized losses on securities available for sale | 55,000 | 91,000
Proceeds from sales of securities held to maturity | 0 | 0
Proceeds from maturities, calls and principal payments of securities held to maturity | 2,341,000 | 0
Gross gains or losses on held to maturity securities | 0 | 0
Securities book value | 26,900,000 | $ 4,500,000
Impairment recognized | $ 0 |

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- Definition Impairment losses related to federal home loan stock. + References No definition available. + Details
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- Definition This item represents the gross profit realized on the sale of debt or equity securities 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 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563 + Details
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