Loans Receivable on Non-accrual Status (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	$ 12,203	$ 13,174
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	6,878	8,734
Commercial Non Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	917	835
Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	2,733	2,287
Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	7	19
Consumer Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	440	329
Residential 1-4 family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	$ 1,228	$ 970