Federal Home Loan Bank Advances - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Advances from FHLB	$ 17,500	$ 17,500
Maturities, year from	2017
Maturities, year to	2019
Outstanding letters of credit with FHLB	$ 19,600	21,200
FHLB borrowings collateralized by residential mortgage loans	102,150	$ 138,600
FHLB maximum borrowing capacity	144,268
FHLB remaining borrowing capacity	$ 76,168
Minimum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Maturities from January 2017 through October 2019, fixed rates	1.50%
Maximum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Maturities from January 2017 through October 2019, fixed rates	4.25%
Weighted Average [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Maturities from January 2017 through October 2019, fixed rates	2.06%

Discloses the earliest year of maturity for the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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- Definition

Enter the last year of maturity for the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

+ References

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- Definition

Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

+ References

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

Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

+ References

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- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

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- Definition

Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

+ References

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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