Financial Instruments Notional Amounts (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$ 73	$ 525	$ 125
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	1,313	2,057	3,159
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$ 0	$ 9	$ 12