Borrowings - Schedule of Borrowings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Oct. 15, 2015	Dec. 31, 2014
Short-term Debt [Line Items]
Total Short-term borrowings	$ 43		$ 78
Current portion of long-term borrowings:
Total Current portion of long-term borrowings	813		83
Unamortized discount and unamortized deferred financing costs	(10)		0
Total Short-term and current portion of long-term borrowings	856		161
Long-term borrowings:
Total Long-term borrowings	18,737		20,697
Unamortized discount and unamortized deferred financing costs	(174)		(226)
Total Borrowings	19,593		20,858
Fair value of long-term borrowings	19,600		22,100
New Accounting Pronouncement, Early Adoption, Effect | Other long-term assets
Long-term borrowings:
Unamortized deferred financing costs			(62)
New Accounting Pronouncement, Early Adoption, Effect | Long-term debt
Long-term borrowings:
Unamortized deferred financing costs			62
Foreign lines of credit and other arrangements
Short-term Debt [Line Items]
Total Short-term borrowings	43		68
Senior secured revolving credit facility
Short-term Debt [Line Items]
Total Short-term borrowings	0		10
8.75% Senior secured second lien notes due 2022
Current portion of long-term borrowings:
Total Current portion of long-term borrowings	750		0
Long-term borrowings:
Total Long-term borrowings	$ 0		1,000
Interest rate	8.75%
4.95% Unsecured notes due 2015
Current portion of long-term borrowings:
Total Current portion of long-term borrowings	$ 0		10
Long-term borrowings:
Interest rate	4.95%
Capital lease obligations
Current portion of long-term borrowings:
Total Current portion of long-term borrowings	$ 73		73
Long-term borrowings:
Total Long-term borrowings	122		134
Senior secured term loan facility due March 2017 at LIBOR and euro LIBOR plus 3.5% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.5%
Long-term borrowings:
Total Long-term borrowings	$ 0		1,461
Senior secured term loan facility due March 2017 at LIBOR and euro LIBOR plus 3.5% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.5% | Euro LIBOR
Long-term borrowings:
Basis spread on variable rate (as a percent)	3.50%
Senior secured term loan facility due March 2017 at LIBOR and euro LIBOR plus 3.5% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.5% | Base rate
Long-term borrowings:
Basis spread on variable rate (as a percent)	2.50%
Senior secured term loan facility due March 2018 at LIBOR and euro LIBOR plus 3.5% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.5%
Long-term borrowings:
Total Long-term borrowings	$ 4,938		4,977
Senior secured term loan facility due March 2018 at LIBOR and euro LIBOR plus 3.5% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.5% | Euro LIBOR
Long-term borrowings:
Basis spread on variable rate (as a percent)	3.50%
Senior secured term loan facility due March 2018 at LIBOR and euro LIBOR plus 3.5% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.5% | Base rate
Long-term borrowings:
Basis spread on variable rate (as a percent)	2.50%
Senior secured term loan facility due September 2018 at LIBOR plus 3.5% or a base rate plus 2.5%
Long-term borrowings:
Total Long-term borrowings	$ 1,008		1,008
Senior secured term loan facility due September 2018 at LIBOR plus 3.5% or a base rate plus 2.5% | LIBOR
Long-term borrowings:
Basis spread on variable rate (as a percent)	3.50%
Senior secured term loan facility due September 2018 at LIBOR plus 3.5% or a base rate plus 2.5% | Base rate
Long-term borrowings:
Basis spread on variable rate (as a percent)	2.50%
Senior secured term loan facility due March 2021 at LIBOR and euro LIBOR plus 4.0% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 3.0%
Long-term borrowings:
Total Long-term borrowings	$ 1,171		1,191
Senior secured term loan facility due March 2021 at LIBOR and euro LIBOR plus 4.0% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 3.0% | Euro LIBOR
Long-term borrowings:
Basis spread on variable rate (as a percent)	4.00%
Senior secured term loan facility due March 2021 at LIBOR and euro LIBOR plus 4.0% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 3.0% | Base rate
Long-term borrowings:
Basis spread on variable rate (as a percent)	3.00%
Senior secured term loan facility due July 2022 at LIBOR and euro LIBOR plus 3.75% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.75%
Long-term borrowings:
Total Long-term borrowings	$ 2,464		0
Senior secured term loan facility due July 2022 at LIBOR and euro LIBOR plus 3.75% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.75% | Euro LIBOR
Long-term borrowings:
Basis spread on variable rate (as a percent)	3.75%
Senior secured term loan facility due July 2022 at LIBOR and euro LIBOR plus 3.75% or, solely with respect to U.S. dollar-denominated term loans, a base rate plus 2.75% | Base rate
Long-term borrowings:
Basis spread on variable rate (as a percent)	2.75%
7.375% Senior secured first lien notes due 2019
Long-term borrowings:
Total Long-term borrowings	$ 0		1,595
Interest rate	7.375%
8.875% Senior secured first lien notes due 2020
Long-term borrowings:
Total Long-term borrowings	$ 0		510
Interest rate	8.875%
6.75% Senior secured first lien notes due 2020
Long-term borrowings:
Total Long-term borrowings	$ 1,398		1,398
Interest rate	6.75%
5.375% Senior secured first lien notes due 2023
Long-term borrowings:
Total Long-term borrowings	$ 1,210		0
Interest rate	5.375%
5.0% Senior secured first lien notes due 2024
Long-term borrowings:
Total Long-term borrowings	$ 1,000		0
Interest rate	5.00%
8.25% Senior secured second lien notes due 2021
Long-term borrowings:
Total Long-term borrowings	$ 0		2,000
Interest rate	8.25%
5.75% Senior secured second lien notes due 2024
Long-term borrowings:
Total Long-term borrowings	$ 2,200		0
Interest rate	5.75%
12.625% Senior unsecured notes due 2021
Long-term borrowings:
Total Long-term borrowings	$ 0		3,000
Interest rate	12.625%	12.625%
10.625% Senior unsecured notes due 2021
Long-term borrowings:
Total Long-term borrowings	$ 0		530
Interest rate	10.625%
11.25% Senior unsecured notes due 2021
Long-term borrowings:
Total Long-term borrowings	$ 0		510
Interest rate	11.25%	11.25%
7.0% Senior unsecured notes due 2023
Long-term borrowings:
Total Long-term borrowings	$ 3,400		0
Interest rate	7.00%
11.75% Senior unsecured subordinated notes due 2021
Long-term borrowings:
Total Long-term borrowings	$ 0		$ 1,609
Interest rate	11.75%