Fair Value Measurements (Fair Value Techniques) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer Financing Notes Receivable	$ 192	$ 264
Long-term debt (excluding capitalized leases) Fair Value Disclosure	(35,828)	(38,615)
Portion at Other than Fair Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer Financing Notes Receivable	195	271
Long-term debt (excluding capitalized leases) Fair Value Disclosure	(31,250)	(31,512)
Level 1 | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer Financing Notes Receivable	0	0
Long-term debt (excluding capitalized leases) Fair Value Disclosure	0	0
Level 2 | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer Financing Notes Receivable	192	264
Long-term debt (excluding capitalized leases) Fair Value Disclosure	(35,778)	(38,540)
Level 3 | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer Financing Notes Receivable	0	0
Long-term debt (excluding capitalized leases) Fair Value Disclosure	$ (50)	$ (75)