Goodwill and Other Intangible Assets and Liabilities (Schedule of Earnings to Be Recognized on below Market Sales Contract) (Details) (USD $) In Millions	6 Months Ended
	Jun. 30, 2011
Goodwill and Other Intangible Assets and Liabilities
Below-market sales contracts revenue for 2011 (remaining six months)	$ 34.6
Below-market sales contracts revenue for 2012	48.8
Below-market sales contracts revenue for 2013	45.3
Below-market sales contracts revenue for 2014	23.0
Below-market sales contracts revenue for 2015	23.0
Below-market sales contracts revenue for 2016	23.1
Total	$ 197.8