Segment Information Summarized Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information
Net Income (Loss) Available to Common Stockholders, Basic									$ 677	$ 3,433	$ 314
Other Nonoperating Income (Expense)									(602)	(1,048)	(775)
Adjusted EBITDA by Segment									2,850	2,638	1,895
Income Tax Benefit (Expense)	$ 33	$ (74)	$ (34)	$ (90)	$ 3,189	$ (16)	$ (18)	$ (5)	(165)	3,150	76
Revenue	2,032	2,033	2,056	2,051	2,053	2,062	2,061	2,053	8,172	8,229	6,777
Capital expenditures									(1,334)	(1,229)	(910)
Depreciation and amortization	(320)	$ (319)	$ (310)	$ (301)	(294)	$ (296)	$ (288)	$ (288)	(1,250)	(1,166)	(808)
Total Assets	24,888				24,017				24,888	24,017
Share-based Compensation									(156)	(141)	(73)
non-cash impairment									0	0	(1)
Corporate and Other [Member]
Segment Reporting Information
Adjusted EBITDA by Segment									(878)	(947)	(732)
Capital expenditures									(149)	(164)	(145)
Total Assets	127				129				127	129
North America
Segment Reporting Information
Adjusted EBITDA by Segment									3,220	3,048	2,065
Capital expenditures									(874)	(752)	(495)
Total Assets	20,818				19,961				20,818	19,961
Europe
Segment Reporting Information
Adjusted EBITDA by Segment									215	235	214
Capital expenditures									(145)	(158)	(117)
Total Assets	1,639				1,796				1,639	1,796
Latin America
Segment Reporting Information
Adjusted EBITDA by Segment									293	302	348
Capital expenditures									(166)	(155)	$ (153)
Total Assets	$ 2,304				$ 2,131				$ 2,304	$ 2,131