Goodwill And Other Intangible Assets And Liabilities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010		Dec. 31, 2009
Increase in balance of Goodwill			$ 1,045.8		$ 111.9	[1]
Goodwill	1,237.7		1,237.7		196.5	[1]	74.6	[1]
Amortization expense relating to intangible assets	3.3	5.6	12.5	13.5
Revenues	2,124.4	1,287.2	4,962.4	3,074.8
Upper Limit [Member]
Below-market sales contracts life (in years)	8.5		8.5
Lower Limit [Member]
Below-market sales contracts life (in years)	3.5		3.5
Below-Market Sales Contracts [Member]
Revenues	$ 16.7	$ 22.9	$ 40.4	$ 34.7

[1] Represents a 12-month rollforward of our goodwill by reportable unit at December 31, 2010.