Debt - Components (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Short-term debt:
Total short-term debt	$ 729	$ 504
Long-term debt:
Senior notes, net	9,067	8,939
Other long-term debt, net	326	248
Total long-term debt	9,393	9,187
Total debt	10,122	9,691
Senior notes
Long-term debt:
Senior notes, net	9,067	8,939
Unamortized discounts and debt issuance costs	66	61
Debt repurchase amount	17
Debt instrument face value	9,700	9,000
Senior notes | Other income/(expense), net
Long-term debt:
Gain on repurchase of debt instrument	3
Other
Long-term debt:
Other long-term debt, net	127	49
Other
Short-term debt:
Total short-term debt	129	86
Commercial Paper | Line of Credit
Short-term debt:
Short-term debt		$ 93
Weighted average interest rate, short-term (as a percentage)		2.20%
Senior Secured Hedged Inventory Facility | Line of Credit
Short-term debt:
Short-term debt		$ 325
Weighted average interest rate, short-term (as a percentage)		2.70%
5.00% senior notes due February 2021 | Senior notes
Short-term debt:
Senior Notes, Current	$ 600
Stated percentage	5.00%
GO Zone term loans | Term loan
Long-term debt:
Other long-term debt, net	$ 199	$ 199
Debt issuance costs	$ 1	$ 1
Weighted average interest rate, long-term	1.30%	2.60%
Level 2 | Senior notes
Long-term debt:
Debt instrument fair value	$ 9,700	$ 9,300