Schedule of Supplemental Balance Sheet Information Related to Operating Leases (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 1,252	$ 1,182
Operating Lease, Weighted Average Remaining Lease Term	9 years	9 years
Operating Lease, Weighted Average Discount Rate, Percent	3.43%	3.35%
Other Noncurrent Liabilities [Member]
Leases [Abstract]
Operating Lease, Liability, Noncurrent	$ 1,084	$ 978
Lessee, Lease, Description [Line Items]
Operating Lease, Liability, Noncurrent	1,084	978
Other Current Liabilities [Member]
Leases [Abstract]
Operating Lease, Liability, Current	268	252
Lessee, Lease, Description [Line Items]
Operating Lease, Liability, Current	268	252
Liabilities, Total
Leases [Abstract]
Operating Lease, Liability	1,352	1,230
Lessee, Lease, Description [Line Items]
Operating Lease, Liability	$ 1,352	$ 1,230