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	Dec. 31, 2018	Dec. 31, 2017
Loans And Allowance For Loan Losses [Line Items]
Impaired loans, Allowance for loan losses	$ 2,696	$ 4,243
All other loans, Allowance for loan losses	157,236	155,289
Impaired loans, Loans outstanding	78,616	114,795
All other loans, Loans outstanding	14,061,682	13,868,879
Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired loans, Allowance for loan losses	1,780	3,067
All other loans, Allowance for loan losses	91,089	90,637
Impaired loans, Loans outstanding	61,496	92,613
All other loans, Loans outstanding	8,790,378	8,532,213
Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Impaired loans, Allowance for loan losses	916	1,176
All other loans, Allowance for loan losses	66,147	64,652
Impaired loans, Loans outstanding	17,120	22,182
All other loans, Loans outstanding	$ 5,271,304	$ 5,336,666