Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets:
Investments	$ 11	$ 11
Foreign Exchange Contracts	1	11
Total Assets at Fair Value	12	22
Liabilities:
Foreign Exchange Contracts	34	19
Total Liabilities at Fair Value	34	19
Supplemental Fair Value Information
Carrying amount — liability	5,334	5,066
Notes Payable and Overdrafts	406	348
Fixed Rate Debt, Excluding Capital Leases
Supplemental Fair Value Information
Carrying amount — liability	4,094	3,434
Fair value — liability	4,283	3,558
Notes Payable and Overdrafts	227	143
Variable Rate Debt, Excluding Capital Leases
Supplemental Fair Value Information
Carrying amount — liability	1,240	1,632
Fair value — liability	1,197	1,632
Notes Payable and Overdrafts	179	205
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)
Assets:
Investments	11	11
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	11	11
Liabilities:
Foreign Exchange Contracts	0	0
Total Liabilities at Fair Value	0	0
Supplemental Fair Value Information
Fair value — liability	4,391	3,808
Significant Other Observable Inputs (Level 2)
Assets:
Investments	0	0
Foreign Exchange Contracts	1	11
Total Assets at Fair Value	1	11
Liabilities:
Foreign Exchange Contracts	34	19
Total Liabilities at Fair Value	34	19
Significant Unobservable Inputs (Level 3)
Assets:
Investments	0	0
Foreign Exchange Contracts	0	0
Total Assets at Fair Value	0	0
Liabilities:
Foreign Exchange Contracts	0	0
Total Liabilities at Fair Value	$ 0	$ 0