Derivative Instruments (Change In Fair Value Of Derivative Instruments) (Details) - Non-hedging interest rate derivatives: - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Assets | Other Income | Customer Back-to-Back Swap Program
Derivatives, Fair Value [Line Items]
Change in Fair Value Non-Hedging Interest Rate Derivatives:	$ (3,999)	$ (4,615)	$ (22,138)	$ 37,103
Other Liabilities | Other Income | Customer Back-to-Back Swap Program
Derivatives, Fair Value [Line Items]
Change in Fair Value Non-Hedging Interest Rate Derivatives:	3,999	4,615	22,138	(37,103)
Other Liabilities | Other Expense
Derivatives, Fair Value [Line Items]
Change in Fair Value Non-Hedging Interest Rate Derivatives:	$ 59	$ (20)	$ 411	$ 163