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Securities - Additional Information (Detail) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2016 USD ($) Securities | Sep. 30, 2015 USD ($) | Sep. 30, 2016 USD ($) Securities Obligation Security | Sep. 30, 2015 USD ($) | Dec. 31, 2015 Securities Obligation
Amortized Cost and Fair Value Debt Securities [Abstract] |  |  |  |  |
Number of U.S. agency and mortgage-backed securities | Securities | 7 |  | 7 |  | 52
Number of obligations of state and political subdivisions in an unrealized loss position | Obligation |  |  | 0 |  | 13
Percentage of investment portfolio |  |  | 100.00% |  | 100.00%
Weighted-average period of re-pricing of portfolio |  |  | 4 years |  | 4 years 7 months 6 days
Gross gains or losses on held to maturity securities |  |  | $ 0 |  |
Proceeds from sales of securities held to maturity | $ 0 | $ 0 | $ 657,000 | $ 0 |
Held to maturity securities, number of securities sold | Security |  |  | 1 |  |
Impairment recognized |  |  | $ 0 |  |

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- Definition Amortized cost and fair value debt securities. + References No definition available. + Details
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- Definition Impairment losses related to federal home loan stock. + References No definition available. + Details
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- Definition Number obligation of state and political subdivisions in unrealized loss position. + References No definition available. + Details
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- Definition This item represents the gain (loss) realized on the sale of held-to-maturity securities disposed of during the period. Additionally, this item may include, if not separately presented, any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt securities which are being or have been recognized in earnings during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27405-111563 + Details
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- Definition The cash inflow associated with the sale of securities that had been designated as held-to-maturity. Excludes proceeds from maturities, prepayments and calls by the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26853-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3179-108585 + Details
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