v3.20.4
Fair Value Measurements And Disclosure (Fair Value Leveling) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-Sale Debt Securities $ 1,479 $ 1,444
Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   2
Cross-currency swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 1,721 172
Liability Derivatives (1,814) (3,187)
Interest rate locks    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   11
Liability Derivatives   (95)
Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 6 89
Liability Derivatives (9)  
Fixed income equities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 236 229
Domestic equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 1,010 844
International equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 180 183
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-Sale Debt Securities 0 0
Level 1 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   0
Level 1 | Cross-currency swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 0 0
Liability Derivatives 0 0
Level 1 | Interest rate locks    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   0
Liability Derivatives   0
Level 1 | Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 0 0
Liability Derivatives 0  
Level 1 | Fixed income equities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 236 229
Level 1 | Domestic equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 1,010 844
Level 1 | International equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 180 183
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-Sale Debt Securities 1,479 1,444
Level 2 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   2
Level 2 | Cross-currency swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 1,721 172
Liability Derivatives (1,814) (3,187)
Level 2 | Interest rate locks    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   11
Liability Derivatives   (95)
Level 2 | Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 6 89
Liability Derivatives (9)  
Level 2 | Fixed income equities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 0 0
Level 2 | Domestic equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 0 0
Level 2 | International equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 0 0
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-Sale Debt Securities 0 0
Level 3 | Interest rate swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   0
Level 3 | Cross-currency swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 0 0
Liability Derivatives 0 0
Level 3 | Interest rate locks    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives   0
Liability Derivatives   0
Level 3 | Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Asset Derivatives 0 0
Liability Derivatives 0  
Level 3 | Fixed income equities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 0 0
Level 3 | Domestic equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities 0 0
Level 3 | International equities | Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity Securities $ 0 $ 0