Loans and the Allowance for Credit Losses - TDRs Defaulted Later Restructured (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) Defaults	Dec. 31, 2015 USD ($) Defaults
Financing Receivable, Modifications [Line Items]
Number of Defaults \| Defaults	1	3
Recorded Investment \| $	$ 16	$ 392
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults \| Defaults		2
Recorded Investment \| $		$ 370
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults \| Defaults		1
Recorded Investment \| $		$ 22
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults \| Defaults	1
Recorded Investment \| $	$ 16
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults \| Defaults		2
Recorded Investment \| $		$ 370

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

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- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

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