Past Due Loans, Allowance For Credit Losses, and Impaired Loans (Detail) - TDRs That Defaulted Within Twelve Months of the Restructured Date (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 loan	Dec. 31, 2012 loan	Dec. 31, 2011 loan
Number of loans	4	5	5
Recorded investment (in Dollars)	$ 704	$ 1,616	$ 939
Commercial And Industrial
Number of loans	1	0	1
Recorded investment (in Dollars)	350	0	128
Office Retail And Industrial
Number of loans	0	2	1
Recorded investment (in Dollars)	0	837	397
Other Commercial Real Estate
Number of loans	3	2	0
Recorded investment (in Dollars)	354	717	0
Home Equity 1
Number of loans	0	0	1
Recorded investment (in Dollars)	0	0	83
1-4 family mortgages
Number of loans	0	1	2
Recorded investment (in Dollars)	$ 0	$ 62	$ 331