Loans - Restructured in Troubled Debt (Detail) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2016 USD ($) Loans	Dec. 31, 2015 USD ($) Loans
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loans	15	16
Loan Balance	$ 12,072	$ 14,941
Specific Reserve	$ 2,553	$ 2,912
Commercial, Industrial, and Agricultural [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loans	7	8
Loan Balance	$ 2,710	$ 5,040
Specific Reserve	$ 128	$ 887
Commercial Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loans	8	8
Loan Balance	$ 9,362	$ 9,901
Specific Reserve	$ 2,425	$ 2,025
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loans	0	0
Loan Balance	$ 0	$ 0
Specific Reserve	$ 0	$ 0
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loans	0	0
Loan Balance	$ 0	$ 0
Specific Reserve	$ 0	$ 0
Credit Cards [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| Loans	0	0
Loan Balance	$ 0	$ 0
Specific Reserve	$ 0	$ 0

Financing receivable modifications specific reserve.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

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