Significant Non-Cash Investing Activities (Details) (USD $) In Millions	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Significant Non Cash Investing Activities [Abstract]
Grant receivables from outside parties for capital expenditures	$ 17.3	$ 4.3
Purchases of property and equipment accrued in accounts payable	$ 15.4	$ 8.3