Securities - Additional Information (Detail)	12 Months Ended
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

Amortized cost and fair value debt securities.

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- Definition

Impairment losses related to federal home loan stock.

+ References

No definition available.

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- Definition

Number obligation of state and political subdivisions in unrealized loss position.

+ References

No definition available.

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Number of securities in unrealized loss position.

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No definition available.

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- Definition

Percentage of investment portfolio.

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No definition available.

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- Definition

Weighted average period of pricing of portfolio.

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No definition available.

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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

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- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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- Definition

The carrying amount of securities categorized neither as held-to-maturity nor trading which serve as security for borrowings or other arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX210.4-08(b))
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-Publisher SEC
-Name Regulation S-X (SX)
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-Article 4

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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

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- Definition

The cash inflow associated with the maturity, prepayments and calls (requests for early payments) of debt securities designated as held-to-maturity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The cash inflow associated with the sale or maturity (principal being due) of securities not classified as either held-to-maturity securities or trading securities which are classified as available-for-sale securities.

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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.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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