Derivative Financial Instruments (Schedule Of Open Interest Rate Swap Derivative Positions) (Details) - Interest Rate Contract 1.76% Expiration January 2019 [Member] $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)
Derivative [Line Items]
Notional	$ 100
Rate Received, percent	1.76%
Rate Paid	Three Month LIBOR
Expiration	Jan. 31, 2019