Loans and the Allowance for Credit Losses - Loans Identified as TDRs (Detail) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015 USD ($) Contract	Sep. 30, 2014 USD ($) Contract	Sep. 30, 2015 USD ($) Contract	Sep. 30, 2014 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract	1	6	45	22
Pre-Modification Outstanding Recorded Investment	$ 13	$ 697	$ 11,195	$ 1,228
Post-Modification Outstanding Recorded Investment	$ 12	$ 684	$ 10,313	$ 1,162
Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract	1		8
Pre-Modification Outstanding Recorded Investment	$ 13		$ 1,065
Post-Modification Outstanding Recorded Investment	$ 12		$ 1,002
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract		2	7	4
Pre-Modification Outstanding Recorded Investment		$ 475	$ 9,336	$ 692
Post-Modification Outstanding Recorded Investment		$ 465	$ 8,541	$ 664
Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract			2
Pre-Modification Outstanding Recorded Investment			$ 42
Post-Modification Outstanding Recorded Investment			$ 50
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract	1	2	15	4
Pre-Modification Outstanding Recorded Investment	$ 13	$ 475	$ 10,401	$ 692
Post-Modification Outstanding Recorded Investment	$ 12	$ 465	$ 9,543	$ 664
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract		1	8	5
Pre-Modification Outstanding Recorded Investment		$ 112	$ 466	$ 286
Post-Modification Outstanding Recorded Investment		$ 112	$ 447	$ 278
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract		2	19	12
Pre-Modification Outstanding Recorded Investment		$ 52	$ 279	$ 191
Post-Modification Outstanding Recorded Investment		$ 50	$ 267	$ 163
Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications \| Contract		1	1	1
Pre-Modification Outstanding Recorded Investment		$ 58	$ 7	$ 59
Post-Modification Outstanding Recorded Investment		$ 57	$ 6	$ 57

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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=49124121&loc=SL6953676-111524

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