Long-Term Debt - Schedule of Maturities of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Long-term Debt, Fiscal Year Maturity
2017	$ 1,038
2018	2,160
2019	1,289
2020	527
2021	345
Thereafter	1,753
Total	7,112	$ 8,098
Amortization of Debt Discount and Debt Issuance Cost, net
2017	(28)
2018	(35)
2019	(23)
2020	(5)
2021	(5)
Thereafter	(8)
Total	(104)	(152)
Long-term debt	$ 7,008	$ 7,946