Allowance for Loan Losses - Schedule of Troubled Debt Restructurings (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2016 USD ($) Contract	Mar. 31, 2015 USD ($) Contract
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts \| Contract	6	5
Pre-Modification Outstanding Recorded Investment	$ 1,329	$ 421
Post-Modification Outstanding Recorded Investment	$ 1,329	$ 421
Commercial and Agriculture [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts \| Contract	3	1
Pre-Modification Outstanding Recorded Investment	$ 483	$ 6
Post-Modification Outstanding Recorded Investment	$ 483	$ 6
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts \| Contract	1	3
Pre-Modification Outstanding Recorded Investment	$ 232	$ 374
Post-Modification Outstanding Recorded Investment	$ 232	$ 374
Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts \| Contract		1
Pre-Modification Outstanding Recorded Investment		$ 41
Post-Modification Outstanding Recorded Investment		$ 41
Farm Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Contracts \| Contract	2
Pre-Modification Outstanding Recorded Investment	$ 614
Post-Modification Outstanding Recorded Investment	$ 614

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=49124121&loc=SL6953676-111524

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