Allowance for Loan Losses - Schedule of Troubled Debt Restructurings (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015 Contract	Mar. 31, 2014 Contract
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts	5	2
Pre-Modification Outstanding Recorded Investment	$ 421	$ 149
Post-Modification Outstanding Recorded Investment	421	149
Commercial and Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts	1
Pre-Modification Outstanding Recorded Investment	6
Post-Modification Outstanding Recorded Investment	6
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts	3	2
Pre-Modification Outstanding Recorded Investment	374	149
Post-Modification Outstanding Recorded Investment	374	149
Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts	1
Pre-Modification Outstanding Recorded Investment	41
Post-Modification Outstanding Recorded Investment	$ 41

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

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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