Loans Receivable on Non-accrual Status (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	$ 17,223	$ 16,806
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	11,434	11,338
Commercial Non Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	1,351	1,340
Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	2,872	2,536
Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	39	65
Consumer Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	356	307
Residential 1-4 family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Receivable on Non-accrual Status	$ 1,171	$ 1,220