Derivative Instruments And Hedging Activities (Schedule Of Notional Values And Fair Values Of Derivative Instruments Designated As Hedging Instruments) (Details) - Cash Flow Interest Rate Contracts [Member] - Designated As Hedging Instrument [Member] - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Assets, Notional Value	$ 250,000,000	$ 540,000,000
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	$ 4,896,000	$ 7,683,000