Loans - Non-Residential Real Estate Loan Portfolio (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	$ 235,845	$ 244,241
Land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	34,154	34,681
Manufacturing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	3,907	3,962
Professional, Technical [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	1,784	1,819
Retail Trade [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	11,902	10,916
Other Services [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	18,846	21,307
Finance and Insurance [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	2,439	1,862
Agricultural, Forestry, Fishing & Hunting [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	47,608	51,868
Real Estate and Rental and Leasing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	55,778	55,692
Wholesale Trade [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	21,486	21,852
Arts, Entertainment and Recreation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	3,656	3,015
Accommodations / Food Service [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	24,004	26,552
Healthcare and Social Assistance [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	6,668	6,862
Transportation and Warehousing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	1,069	1,101
Information [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	2,309	2,390
Admin Support / Waste Mgmt [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non residential real estate loan portfolio, Total	$ 235	$ 362