Segment Information Summarized Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information
Net Income (Loss) Available to Common Stockholders, Basic									$ 3,433	$ 314	$ (109)
Other Nonoperating Income (Expense)									(1,048)	(775)	(737)
Adjusted EBITDA by Segment [Line Items]									2,638	1,895	1,624
Income Tax Benefit (Expense)	$ 3,189	$ (16)	$ (18)	$ (5)	$ 103	$ (8)	$ (12)	$ (7)	3,150	76	(38)
Revenue	2,053	2,062	2,061	2,053	1,914	1,629	1,625	1,609	8,229	6,777	6,313
Capital expenditures									(1,229)	(910)	(760)
Depreciation and amortization	(294)	$ (296)	$ (288)	$ (288)	(250)	$ (187)	$ (187)	$ (184)	(1,166)	(808)	(800)
Total Assets	24,145				20,947				24,145	20,947
Share-based Compensation									(141)	(73)	(151)
non-cash impairment									0	(1)	(7)
Corporate and Other [Member]
Segment Reporting Information
Adjusted EBITDA by Segment [Line Items]									(947)	(732)	(714)
Capital expenditures									(164)	(145)	(100)
Total Assets	257				284				257	284
North America [Member]
Segment Reporting Information
Adjusted EBITDA by Segment [Line Items]									3,048	2,065	1,799
Capital expenditures									(752)	(495)	(398)
Total Assets	19,961				16,242				19,961	16,242
Europe [Member]
Segment Reporting Information
Adjusted EBITDA by Segment [Line Items]									235	214	226
Capital expenditures									(158)	(117)	(128)
Total Assets	1,796				1,970				1,796	1,970
Latin America [Member]
Segment Reporting Information
Adjusted EBITDA by Segment [Line Items]									302	348	313
Capital expenditures									(155)	(153)	$ (134)
Total Assets	$ 2,131				$ 2,451				$ 2,131	$ 2,451