Interest Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest Expense
Interest on borrowings	$ 28.0	$ 29.8
Fees on financing agreements	5.1	24.9
Interest capitalized and other	(2.2)	(2.6)
Total interest expense	30.9	52.1
Amortization of debt issuance costs upon repayment of senior secured term loan		$ 19.9