Loans And Allowance For Loan Losses (Allowance For Loan Losses And Related Loan Balance Disaggregated On The Basis Of Impairment Methodology) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Loans And Allowance For Loan Losses [Line Items]
Impaired Loans, Allowance for Loan Losses	$ 8,670	$ 10,758
Impaired Loans, Loans Outstanding	135,895	139,255
All Other Loans, Allowance for Loan Losses	169,863	173,774
All Other Loans, Loans Outstanding	9,241,020	9,038,223
Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Loans, Allowance for Loan Losses	6,624	6,668
Impaired Loans, Loans Outstanding	108,916	108,167
All Other Loans, Allowance for Loan Losses	108,047	115,829
All Other Loans, Loans Outstanding	5,421,037	5,266,796
Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired Loans, Allowance for Loan Losses	2,046	4,090
Impaired Loans, Loans Outstanding	26,979	31,088
All Other Loans, Allowance for Loan Losses	61,816	57,945
All Other Loans, Loans Outstanding	$ 3,819,983	$ 3,771,427