Fair Value Measurements Fair Value Measurements (Carrying Amounts And Fair Values Of Financial Instruments) (Details) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable and current portion of long-term debt	$ 8	$ 11
Long-term debt	22,168	21,193
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable and current portion of long-term debt	8	11
Long-term debt	$ 22,796	$ 23,004