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	Jun. 30, 2015	Dec. 31, 2014
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	$ 11,872,905	$ 11,388,150
Impaired Financing Receivable, Recorded Investment	55,576	81,088
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	147,776	149,691
Impaired Financing Receivable, Related Allowance	3,756	6,841
Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	6,961,839	6,606,123
Impaired Financing Receivable, Recorded Investment	31,276	55,551
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	84,386	85,095
Impaired Financing Receivable, Related Allowance	1,943	4,527
Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	4,911,066	4,782,027
Impaired Financing Receivable, Recorded Investment	24,300	25,537
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	63,390	64,596
Impaired Financing Receivable, Related Allowance	$ 1,813	$ 2,314