Loans (Summary Of Impaired Financial Receivables (Summary Of Covered Impaired Loans)) (Detail) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Nonaccrual loans	$ 200,000
Troubled debt restructurings not included above	28,200,000		26,100,000
Covered Loan
Nonaccrual loans	151,225,000	135,545,000	159,999,000
Troubled debt restructurings not included above	14,842,000	9,312,000	19,884,000
Total impaired loans	166,067,000	144,857,000	179,883,000
Impaired loans not requiring a related allowance	166,067,000	144,857,000	179,883,000
Impaired loans requiring a related allowance
Allowance related to impaired loans
Average investment in impaired loans	178,130,000	119,950,000	138,950,000
Interest income recognized on impaired loans	628,000	287,000	526,000
Foregone interest income on impaired loans	$ 482,000	$ 122,000	$ 202,000