Summary of Significant Accounting Policies Property, Plant and Equipment (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment
Property, plant and equipment, at cost	$ 13,406	$ 12,762
Accumulated depreciation	(6,335)	(5,850)
Property, plant, and equipment, net	7,071	6,912
Land and land improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	628	619
Buildings and improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	2,762	2,575
Machinery and other equipment
Property, Plant and Equipment
Property, plant and equipment, at cost	7,206	6,997
Capitalized software costs
Property, Plant and Equipment
Property, plant and equipment, at cost	602	606
Leasehold improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	$ 2,208	$ 1,965
Minimum | Capitalized software costs
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	3 years
Maximum [Member] | Land and land improvements
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	40 years
Maximum [Member] | Buildings and improvements
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	45 years
Maximum [Member] | Machinery and other equipment
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	20 years
Maximum [Member] | Capitalized software costs
Property, Plant and Equipment
Property, plant and equipment, estimated useful life	5 years