Supplemental Disclosure of Cash Flow Information (Details) (USD $) In Millions	9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010
Cash paid during the period [Abstract]
Interest (net of amount capitalized)	$ 149.6	[1]	$ 116.9
Non-cash adjustments [Abstract]
Accounts payable and PPE	$ 10.4		$ 29.0

[1] The 2011 period includes $21.0 million of premiums paid for the 2013 Notes redemption.