Significant Non-Cash Investing Activities (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Receivables from outside parties for the funding of capital expenditures	$ 32.3	$ 23.2
Purchases of property and equipment accrued in accounts payable but not yet paid	$ 39.8	$ 20.5