Debt - Long-term And Short-term Debt (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	May 31, 2020
Debt Disclosure [Abstract]
Commercial paper and U.S. bank borrowings	$ 2,944,000,000	$ 996,000,000
Other bank borrowings (primarily international)	735,000,000	736,000,000
Total short-term debt	3,679,000,000	1,732,000,000
Debt Instrument [Line Items]
Long-term debt	13,801,000,000	12,224,000,000
Obligations under finance leases	140,000,000
Obligations under finance leases		149,000,000
Less: current portion of long-term debt	(2,723,000,000)	(1,531,000,000)
Total long-term debt	11,078,000,000	10,693,000,000
Total debt	17,480,000,000	13,956,000,000
2.25% Notes due 2020
Debt Instrument [Line Items]
Long-term debt	$ 300,000,000	300,000,000
Interest rate	2.25%
1.75% Euro denominated notes due 2020
Debt Instrument [Line Items]
Long-term debt	$ 1,129,000,000	1,137,000,000
Interest rate	1.75%
0.634% Euro denominated notes due 2020
Debt Instrument [Line Items]
Long-term debt	$ 57,000,000	56,000,000
Interest rate	0.634%
4.05% Notes due 2021
Debt Instrument [Line Items]
Long-term debt	$ 500,000,000	499,000,000
Interest rate	4.05%
3.875% Euro denominated notes due 2021
Debt Instrument [Line Items]
Long-term debt	$ 700,000,000	711,000,000
Interest rate	3.875%
3.00% Notes due 2021
Debt Instrument [Line Items]
Long-term debt	$ 499,000,000	499,000,000
Face amount	$ 500,000,000
Interest rate	3.00%
0.250% Euro denominated notes due 2022
Debt Instrument [Line Items]
Long-term debt	$ 1,130,000,000	1,129,000,000
Interest rate	0.25%
2.45% Notes due 2022
Debt Instrument [Line Items]
Long-term debt	$ 599,000,000	599,000,000
Interest rate	2.45%
2.20% Notes due 2022
Debt Instrument [Line Items]
Long-term debt	$ 499,000,000	499,000,000
Face amount		$ 500,000,000
Interest rate	2.20%	2.20%
2.70% Notes due 2023
Debt Instrument [Line Items]
Long-term debt	$ 499,000,000	$ 499,000,000
Interest rate	2.70%
2.00% Euro denominated notes due 2023
Debt Instrument [Line Items]
Long-term debt	$ 772,000,000	776,000,000
Interest rate	2.00%
5.875% GBP denominated notes due 2023
Debt Instrument [Line Items]
Long-term debt	$ 423,000,000	456,000,000
Interest rate	5.875%
1.20% Euro denominated notes due 2024
Debt Instrument [Line Items]
Long-term debt	$ 616,000,000	615,000,000
Interest rate	1.20%
1.875% Euro denominated notes due 2024
Debt Instrument [Line Items]
Long-term debt	$ 360,000,000	361,000,000
Interest rate	1.875%
2.65% Notes due 2025
Debt Instrument [Line Items]
Long-term debt	$ 398,000,000	398,000,000
Interest rate	2.65%
1.625% Euro denominated notes due 2025
Debt Instrument [Line Items]
Long-term debt	$ 557,000,000	556,000,000
Interest rate	1.625%
3.20% Notes due 2026
Debt Instrument [Line Items]
Long-term debt	$ 725,000,000	725,000,000
Interest rate	3.20%
3.434% Notes due 2026
Debt Instrument [Line Items]
Long-term debt	$ 196,000,000	196,000,000
Interest rate	3.434%
1.652% Euro denominated notes due 2027
Debt Instrument [Line Items]
Long-term debt	$ 93,000,000	93,000,000
Interest rate	1.652%
0.250% Euro denominated notes due 2027
Debt Instrument [Line Items]
Long-term debt	$ 840,000,000
Face amount			$ 750,000,000
Interest rate	0.25%		0.25%
1.00% Euro denominated notes due 2028
Debt Instrument [Line Items]
Long-term debt	$ 886,000,000	872,000,000
Interest rate	1.00%
1.90% Euro denominated notes due 2030
Debt Instrument [Line Items]
Long-term debt	$ 117,000,000	118,000,000
Interest rate	1.90%
0.550% Euro denominated notes due 2032
Debt Instrument [Line Items]
Long-term debt	$ 835,000,000	0
Face amount			$ 750,000,000
Interest rate	0.55%		0.55%
3.55% Notes due 2042
Debt Instrument [Line Items]
Long-term debt	$ 664,000,000	662,000,000
Interest rate	3.55%
Other
Debt Instrument [Line Items]
Long-term debt	$ 10,000,000	10,000,000
International bank borrowings
Debt Instrument [Line Items]
Long-term debt	257,000,000	309,000,000
Derivatives Designated as Hedging Instruments: | Fair Value Hedging | Interest Rate Swap
Debt Instrument [Line Items]
Fair value decrease in debt related to hedge accounting	$ 18,000,000	$ 38,000,000