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	Sep. 30, 2015	Dec. 31, 2014
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	$ 12,168,893	$ 11,388,150
Impaired Financing Receivable, Recorded Investment	55,381	81,088
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	148,036	149,691
Impaired Financing Receivable, Related Allowance	3,496	6,841
Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Loans And Leases Receivable Excluding Impaired Financing Receivables Recorded Investment	7,194,779	6,606,123
Impaired Financing Receivable, Recorded Investment	32,513	55,551
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	82,788	85,095
Impaired Financing Receivable, Related Allowance	1,829	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	4,974,114	4,782,027
Impaired Financing Receivable, Recorded Investment	22,868	25,537
Loans and Leases Receivable Allowance Excluding Impaired Financing Receivable Related Allowance	65,248	64,596
Impaired Financing Receivable, Related Allowance	$ 1,667	$ 2,314