Allowance for Loan Losses - Summary of Troubled Debt Restructurings (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014 Contracts	Dec. 31, 2013 Contracts
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of Contracts	2	7
Pre-modification outstanding recorded investment	$ 98	$ 2,836
Post- modification outstanding recorded investment	98	2,690
Construction and Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of Contracts		1
Pre-modification outstanding recorded investment		108
Post- modification outstanding recorded investment		108
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of Contracts	2	2
Pre-modification outstanding recorded investment	98	67
Post- modification outstanding recorded investment	98	64
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of Contracts	1	3
Pre-modification outstanding recorded investment		2,376
Post- modification outstanding recorded investment		2,356
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of Contracts		1
Pre-modification outstanding recorded investment		285
Post- modification outstanding recorded investment		$ 162

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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=35738203&loc=SL6953676-111524

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- Definition

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