Derivative Instruments (Change In Fair Value Of Derivative Instruments) (Details) - Non-hedging interest rate derivatives: - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 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:		$ 37,911
Other Assets | Other Expense | Customer Back-to-Back Swap Program
Derivatives, Fair Value [Line Items]
Change in Fair Value Non-Hedging Interest Rate Derivatives:	$ (22,994)
Other Liabilities | Other Income | Customer Back-to-Back Swap Program
Derivatives, Fair Value [Line Items]
Change in Fair Value Non-Hedging Interest Rate Derivatives:		(37,911)
Other Liabilities | Other Expense
Derivatives, Fair Value [Line Items]
Change in Fair Value Non-Hedging Interest Rate Derivatives:	385	$ 172
Other Liabilities | Other Expense | Customer Back-to-Back Swap Program
Derivatives, Fair Value [Line Items]
Change in Fair Value Non-Hedging Interest Rate Derivatives:	$ 22,994