Debt Long-Term Debt Maturities (Details) (USD $)	12 Months Ended								0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Revolving Credit Facility	Dec. 18, 2012 Line of Credit [Member] Credit Agreement [Member]	Mar. 16, 2012 Line of Credit [Member] Credit Agreement [Member]	Mar. 16, 2012 Line of Credit [Member] Revolving Credit Facility	Mar. 16, 2012 Loans Payable [Member] Senior Secured Term Loan Facilities with interest payable at various dates at floating rates (2.0% at December 31, 2013) payable through 2018	Mar. 16, 2012 Senior Secured Term Loan Payable Through 2014 - B Line of Credit [Member] Senior Secured Term Loan Payable Through 2014 - A
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,159,300,000			$ 1,000,000,000	$ 300,000,000.0	$ 2,000,000,000.0	$ 1,000,000,000.0	$ 1,000,000,000.0
Line of Credit Facility, Amount Outstanding	361,000,000			296,000,000
Gains (Losses) on Extinguishment of Debt	(27,100,000)	(11,000,000)	(2,100,000)						(8,900,000)
Long-term Debt Maturities
2013	75,000,000
2014	69,200,000
2015	99,900,000
2016	123,200,000
2017	1,452,600,000
After 2017	428,100,000
Total	$ 2,248,000,000	$ 2,325,500,000