Summary Of Commitments And Contingent Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingent Liabilities [Line Items]
Fixed Rate		$ 850
Variable Rate		4,559
Commitments To Sell Loans [Member]
Commitments and Contingent Liabilities [Line Items]
Fixed Rate	52,511	55,098
Variable Rate	0	0
Standby Letters Of Credit [Member]
Commitments and Contingent Liabilities [Line Items]
Fixed Rate	1,408	850
Variable Rate	4,279	4,559
Commitments To Fund Loans [Member]
Commitments and Contingent Liabilities [Line Items]
Fixed Rate	52,461	39,298
Variable Rate	326,173	307,086
Commercial Lines [Member] | Commitments To Fund Loans [Member]
Commitments and Contingent Liabilities [Line Items]
Fixed Rate	13,444	5,341
Variable Rate	187,829	179,790
Consumer Loan [Member] | Commitments To Fund Loans [Member]
Commitments and Contingent Liabilities [Line Items]
Fixed Rate	6,013	3,498
Variable Rate	137,668	126,807
Residential Mortgage [Member] | Commitments To Fund Loans [Member]
Commitments and Contingent Liabilities [Line Items]
Fixed Rate	33,004	30,459
Variable Rate	$ 676	$ 489