Subsequent Events (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		1 Months Ended		3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Apr. 30, 2013 New Term Loan Facility [Member]	Apr. 29, 2013 New Term Loan Facility [Member]	Jun. 30, 2013 Term Loan [Member]	Mar. 31, 2013 Term Loan [Member]	Dec. 31, 2012 Term Loan [Member]	Apr. 29, 2013 LIBOR [Member] Minimum [Member] New Term Loan Facility [Member]	Apr. 29, 2013 LIBOR [Member] Maximum [Member] New Term Loan Facility [Member]
Subsequent Event [Line Items]
Proceeds from Issuance of long-term Debt	$ 0	$ 135.7	$ 1,350.0
Debt, short-term and long-term						1,299.5	1,339.5
Discount, percent of par				99.75%
Variable Interest Rate Margin								2.25%	2.50%
Reference Interest Rate Floor								1.00%
Quarterly amortization payment of original principal, Percent				0.25%
Net loss on extinguishments of long-term debt	$ 3.9	$ 9.4			$ 10.3