Financial Instruments - Economic Hedges (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to interest rate swaps	$ 0	$ (111)	$ 0	$ 0	$ 0	$ 1	$ (5)	$ 14
Not Designated as Hedging Instrument, Economic Hedge
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to interest rate swaps									$ 173	$ 234	$ (241)
Not Designated as Hedging Instrument, Economic Hedge | Commodity contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to interest rate swaps									67	40	(218)
Not Designated as Hedging Instrument, Economic Hedge | Intercompany loans and forecasted interest payments | Currency exchange contracts | Interest and other expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to interest rate swaps									100	98	13
Not Designated as Hedging Instrument, Economic Hedge | Forecasted transactions | Currency exchange contracts | Interest and other expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to interest rate swaps									(3)	(4)	(2)
Not Designated as Hedging Instrument, Economic Hedge | Forecasted transactions | Currency exchange contracts | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to interest rate swaps									17	103	(37)
Not Designated as Hedging Instrument, Economic Hedge | Forecasted transactions | Currency exchange contracts | Selling, general and administrative expenses
Derivative Instruments, Gain (Loss) [Line Items]
Loss related to interest rate swaps									$ (8)	$ (3)	$ 3