Debt 4.75% Senior Notes, due 2022 (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Long-term Debt, Gross	$ 2,346,488,000	$ 2,500,434,000
Current Fiscal Year End Date	--12-31
4.75% Senior Notes, due 2022 [Member]
Long-term Debt, Gross	400,000,000	0
Debt Instrument, Initial Face Value	400,000,000
Deferred Finance Costs, Gross	$ 6,000,000