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	Dec. 31, 2012	Dec. 31, 2011
Loans And Allowance For Loan Losses [Line Items]
Impaired loans, Allowance for loan losses	$ 7,485	$ 10,758
All other loans, Allowance for loan losses	165,047	173,774
Impaired loans, Loans outstanding	116,918	139,255
All other loans, Loans outstanding	9,714,466	9,038,223
Commercial [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired loans, Allowance for loan losses	5,434	6,668
All other loans, Allowance for loan losses	100,291	115,829
Impaired loans, Loans outstanding	80,807	108,167
All other loans, Loans outstanding	5,624,965	5,266,796
Personal Banking [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired loans, Allowance for loan losses	2,051	4,090
All other loans, Allowance for loan losses	64,756	57,945
Impaired loans, Loans outstanding	36,111	31,088
All other loans, Loans outstanding	$ 4,089,501	$ 3,771,427