Basis Of Presentation Basis of Presentation (Revision for Deferred Income Taxes) (Details) (Restatement Adjustment [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Decrease in Current Deferred Tax Assets, Revision of Unrealized Current Derivative Gains, Net [Member]
Adjustment to deferred income taxes due to revision of unrealized current derivative gains, net	$ 77.0
Increase in Current Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member]
Adjustment to deferred income taxes due to revision of unrealized current derivative gains, net	57.7
Decrease in Noncurrent Deferred Tax Liabilities, Revision of Unrealized Current Derivative Gains, Net [Member]
Adjustment to deferred income taxes due to revision of unrealized current derivative gains, net	$ 134.7