Financial and Derivative Instruments (Details) - Commodity - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Assets at Fair Value	$ 10	$ 32
Total Liabilities at Fair Value	147	109
Accounts and notes receivable, net
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Assets at Fair Value	10	30
Long-term receivables, net
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Assets at Fair Value	0	2
Accounts payable
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Liabilities at Fair Value	145	99
Deferred credits and other noncurrent obligations
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Liabilities at Fair Value	$ 2	$ 10