Loans (Summary Of Impaired Financial Receivables (Summary Of Non-Covered Impaired Loans)) (Detail) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Nonaccrual loans	$ 200,000
Troubled debt restructurings not included above	23,300,000		26,100,000
Non-Covered Loans
Nonaccrual loans	38,225,000	59,067,000	70,823,000
Troubled debt restructurings not included above	19,893,000	16,591,000	17,951,000
Total impaired loans	58,118,000	75,658,000	88,774,000
Impaired loans not requiring a related allowance
Impaired loans requiring a related allowance	58,118,000	75,658,000	88,774,000
Allowance related to impaired loans	7,681,000	17,010,000	18,478,000
Average investment in impaired loans	73,353,000	88,207,000	88,320,000
Interest income recognized on impaired loans	376,000	847,000	637,000
Foregone interest income on impaired loans	$ 491,000	$ 202,000	$ 613,000