Long-Term Debt -Term Loan (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Term Loan [Member]
Debt Instrument [Line Items]
Debt, short-term and long-term	$ 1,339.5	$ 1,540.5
Term Loan Repayments	201.0
Term Loan Repayments, optional	180.0
Term Loan Repayments, mandatory	21.0
Senior secured leverage ratio, maximum	7
Senior secured leverage ratio, actual	2.3
Nonextended loans due 2014 [Member]
Debt Instrument [Line Items]
Debt, short-term and long-term	421.3
Extended loans due 2017 [Member]
Debt Instrument [Line Items]
Debt, short-term and long-term	$ 918.2
Greater than 5.5 to 1.0 [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Mandatory prepayments as percentage of excess cash flow	50.00%
Less than or equal to 5.5 but greater than 4.5 [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Mandatory prepayments as percentage of excess cash flow	25.00%
Less than or equal to 4.5 [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Mandatory prepayments as percentage of excess cash flow	0.00%
Maximum, less than or equal to 5.5 [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Net leverage ratio	5.5
Minimum, greater than 4.5 [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Net leverage ratio	4.5
Maximum, less than or equal to 4.5 [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Net leverage ratio	4.5