Derivatives And Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Gains and losses from the effective portion of derivative assets and liabilities held in AOCI expected to be reclassified into earnings	$ 23.2
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net	1.0	11.0
Reduction Of Interest Expense Over Life Of Debt Instruments, next 12 months	$ 2.1
Fair Value Inputs, Level 3 [Member]
Natural gas hedges original tenure	10 years
Fair Value Inputs, Level 3 [Member] | Maximum [Member]
Unobservable inputs included within the fair value calculation	5.40
Fair Value Inputs, Level 3 [Member] | Minimum [Member]
Unobservable inputs included within the fair value calculation	4.04