Derivative Financial Instruments (Summary Of Interest Rate Swaps) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
1.928% Interest Rate Swap [Member]
Derivative [Line Items]
Trade Date	Mar. 27, 2012
Notional Amount	$ 250.0
Interest Rate Paid	1.928%
Coverage Period	March 2012 to March 2018
Risk Coverage	Term Loan B
2.810% Interest Rate Swap [Member]
Derivative [Line Items]
Trade Date	Mar. 27, 2012
Notional Amount	$ 200.0
Interest Rate Paid	2.81%
Coverage Period	November 2015 to March 2018
Risk Coverage	Term Loan B
1.398% Interest Rate Swap [Member]
Derivative [Line Items]
Trade Date	Apr. 16, 2013
Notional Amount	$ 250.0
Interest Rate Paid	1.398%
Coverage Period	November 2015 to March 2018
Risk Coverage	Term Loan A