Derivative Financial Instruments - Schedule of Derivative Financial Instruments on Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest Rate Contracts [Member]
Derivative [Line Items]
Derivatives in fair value hedging relationships	$ (385)	$ (329)	$ 353	$ (658)
Interest Income/ (Expense) [Member]
Derivative [Line Items]
Derivatives in fair value hedging relationships	(385)	(332)	353	(661)
Interest Income/ (Expense) [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Derivatives in fair value hedging relationships	(385)	(332)	353	(661)
Other Income [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, loss	0	3	0	3
Derivative instruments not designated as hedging instruments, net	$ 0	$ 3	$ 0	$ 3

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a),(c),(d),(e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

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Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

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Amount of realized and unrealized loss of derivative instruments not designated or qualifying as hedging instruments.

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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.

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