Financial and Derivative Instruments (Details 1) - Commodity - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Assets at Fair Value	$ 2	$ 283
Total Liabilities at Fair Value	45	12
Accounts and notes receivable, net
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Assets at Fair Value	2	279
Long-term receivables, net
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Assets at Fair Value	0	4
Accounts payable
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Liabilities at Fair Value	43	12
Deferred credits and other noncurrent obligations
Consolidated Balance Sheet: Fair Value of Derivatives not Designated as Hedging Instruments
Total Liabilities at Fair Value	$ 2	$ 0