Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 211,000,000	$ 110,000,000	$ 579,000,000	$ 561,000,000
Effective tax rate	32.30%	52.40%	32.80%	35.90%
Tax benefit associated with loss on early extinguishment of debt		$ 133,000,000		$ 133,000,000
Loss on early extinguishment of debt	$ 0	352,000,000	$ 0	352,000,000
Tax provision associated with impairment charge		22,000,000		22,000,000
Impairment charge	$ 0	52,000,000	$ 0	52,000,000
Establishment of tax reserve for retroactive impact of uncertain tax position in a foreign jurisdiction		$ 19,000,000		$ 19,000,000