Fair Value Measurement - Fair Value Measurement Inputs (Details) - USD ($) $ in Millions | Sep. 30, 2023 | Dec. 31, 2022 |
Investment securities (current and long-term): | | |
Other Assets, Current | $ 406 | $ 381 |
Other assets | 1,709 | 1,601 |
Derivatives: | | |
Derivative Asset | 13 | 170 |
Derivatives: [Abstract] | | |
Derivative Liability | 41 | 42 |
Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Investments, Fair Value Disclosure | 25 | 25 |
Trust Assets Fair Value Disclosure | 61 | 56 |
Derivatives: | | |
Derivative Asset | | 0 |
Discontinued Operation, Contingent Receivable | 0 | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | 0 |
Long-term debt, including current portion | 0 | 0 |
Level 1 | | |
Investment securities (current and long-term): | | |
Investments, Fair Value Disclosure | 5 | 7 |
Trust Assets Fair Value Disclosure | 19 | 3 |
Derivatives: | | |
Derivative Asset | | 4 |
Discontinued Operation, Contingent Receivable | 0 | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | 7 | 0 |
Long-term debt, including current portion | 0 | 0 |
Level 2 | | |
Investment securities (current and long-term): | | |
Investments, Fair Value Disclosure | 0 | 0 |
Trust Assets Fair Value Disclosure | 119 | 122 |
Derivatives: | | |
Derivative Asset | | 166 |
Discontinued Operation, Contingent Receivable | 0 | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | 37 | 42 |
Long-term debt, including current portion | 8,639 | 10,097 |
Level 3 | | |
Investment securities (current and long-term): | | |
Investments, Fair Value Disclosure | 0 | 0 |
Trust Assets Fair Value Disclosure | 0 | 0 |
Derivatives: | | |
Derivative Asset | | 0 |
Discontinued Operation, Contingent Receivable | 47 | 57 |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | 0 |
Long-term debt, including current portion | 0 | 0 |
Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Investments, Fair Value Disclosure | 30 | 32 |
Trust Assets Fair Value Disclosure | 199 | 181 |
Derivatives: | | |
Derivative Asset | | 170 |
Discontinued Operation, Contingent Receivable | 47 | 57 |
Derivatives: [Abstract] | | |
Derivative Liability | 44 | 42 |
Long-term debt, including current portion | 8,639 | 10,097 |
Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Investments, Fair Value Disclosure | 30 | 32 |
Trust Assets Fair Value Disclosure | 199 | 181 |
Derivatives: | | |
Derivative Asset | | 170 |
Discontinued Operation, Contingent Receivable | 55 | 67 |
Derivatives: [Abstract] | | |
Derivative Liability | 44 | 42 |
Long-term debt, including current portion | 9,405 | 10,620 |
Embedded Derivative Financial Instruments | | |
Derivatives: | | |
Derivative Asset | 13 | 166 |
Derivatives: [Abstract] | | |
Derivative Liability | 32 | 39 |
Embedded Derivative Financial Instruments | Fair Value Measured at Net Asset Value Per Share | | |
Derivatives: | | |
Derivative Asset | 0 | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | 0 |
Embedded Derivative Financial Instruments | Level 1 | | |
Derivatives: | | |
Derivative Asset | 0 | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | 0 |
Embedded Derivative Financial Instruments | Level 2 | | |
Derivatives: | | |
Derivative Asset | 16 | 166 |
Derivatives: [Abstract] | | |
Derivative Liability | 35 | 39 |
Embedded Derivative Financial Instruments | Level 3 | | |
Derivatives: | | |
Derivative Asset | 0 | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | 0 |
Embedded Derivative Financial Instruments | Estimate of Fair Value Measurement | | |
Derivatives: | | |
Derivative Asset | 16 | 166 |
Derivatives: [Abstract] | | |
Derivative Liability | 35 | 39 |
Embedded Derivative Financial Instruments | Carrying Amount, Fair Value Disclosure | | |
Derivatives: | | |
Derivative Asset | 16 | 166 |
Derivatives: [Abstract] | | |
Derivative Liability | 35 | 39 |
Forward Contracts | Level 1 | | |
Derivatives: | | |
Derivative Asset | | 1 |
Forward Contracts | Level 2 | | |
Derivatives: | | |
Derivative Asset | | 0 |
Forward Contracts | Level 3 | | |
Derivatives: | | |
Derivative Asset | | 0 |
Forward Contracts | Estimate of Fair Value Measurement | | |
Derivatives: | | |
Derivative Asset | | 1 |
Forward Contracts | Carrying Amount, Fair Value Disclosure | | |
Derivatives: | | |
Derivative Asset | | 1 |
Commodity Contract | | |
Derivatives: | | |
Derivative Asset | 0 | 4 |
Derivatives: [Abstract] | | |
Derivative Liability | 9 | 3 |
Commodity Contract | Fair Value Measured at Net Asset Value Per Share | | |
Derivatives: | | |
Derivative Asset | | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | | 0 |
Commodity Contract | Fair Value Measured at Net Asset Value Per Share | Forward Contracts | | |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | |
Commodity Contract | Fair Value Measured at Net Asset Value Per Share | Futures and Swaps | | |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | |
Commodity Contract | Level 1 | | |
Derivatives: | | |
Derivative Asset | | 3 |
Derivatives: [Abstract] | | |
Derivative Liability | | 0 |
Commodity Contract | Level 1 | Forward Contracts | | |
Derivatives: [Abstract] | | |
Derivative Liability | 1 | |
Commodity Contract | Level 1 | Futures and Swaps | | |
Derivatives: [Abstract] | | |
Derivative Liability | 6 | |
Commodity Contract | Level 2 | | |
Derivatives: | | |
Derivative Asset | | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | | 3 |
Commodity Contract | Level 2 | Forward Contracts | | |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | |
Commodity Contract | Level 2 | Futures and Swaps | | |
Derivatives: [Abstract] | | |
Derivative Liability | 2 | |
Commodity Contract | Level 3 | | |
Derivatives: | | |
Derivative Asset | | 0 |
Derivatives: [Abstract] | | |
Derivative Liability | | 0 |
Commodity Contract | Level 3 | Forward Contracts | | |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | |
Commodity Contract | Level 3 | Futures and Swaps | | |
Derivatives: [Abstract] | | |
Derivative Liability | 0 | |
Commodity Contract | Estimate of Fair Value Measurement | | |
Derivatives: | | |
Derivative Asset | | 3 |
Derivatives: [Abstract] | | |
Derivative Liability | | 3 |
Commodity Contract | Estimate of Fair Value Measurement | Forward Contracts | | |
Derivatives: [Abstract] | | |
Derivative Liability | 1 | |
Commodity Contract | Estimate of Fair Value Measurement | Futures and Swaps | | |
Derivatives: [Abstract] | | |
Derivative Liability | 8 | |
Commodity Contract | Carrying Amount, Fair Value Disclosure | | |
Derivatives: | | |
Derivative Asset | | 3 |
Derivatives: [Abstract] | | |
Derivative Liability | | 3 |
Commodity Contract | Carrying Amount, Fair Value Disclosure | Forward Contracts | | |
Derivatives: [Abstract] | | |
Derivative Liability | 1 | |
Commodity Contract | Carrying Amount, Fair Value Disclosure | Futures and Swaps | | |
Derivatives: [Abstract] | | |
Derivative Liability | 8 | |
U.S. core fixed income fund | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Marketable Securities | 25 | 25 |
Trust Assets Fair Value Disclosure | 61 | 56 |
U.S. core fixed income fund | Level 1 | | |
Investment securities (current and long-term): | | |
Marketable Securities | 0 | 0 |
Trust Assets Fair Value Disclosure | 0 | 0 |
U.S. core fixed income fund | Level 2 | | |
Investment securities (current and long-term): | | |
Marketable Securities | 0 | 0 |
Trust Assets Fair Value Disclosure | 0 | 0 |
U.S. core fixed income fund | Level 3 | | |
Investment securities (current and long-term): | | |
Marketable Securities | 0 | 0 |
Trust Assets Fair Value Disclosure | 0 | 0 |
U.S. core fixed income fund | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Marketable Securities | 25 | 25 |
Trust Assets Fair Value Disclosure | 61 | 56 |
U.S. core fixed income fund | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Marketable Securities | 25 | 25 |
Trust Assets Fair Value Disclosure | 61 | 56 |
Equity securities | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Marketable Securities | 0 | 0 |
Equity securities | Level 1 | | |
Investment securities (current and long-term): | | |
Marketable Securities | 5 | 7 |
Equity securities | Level 2 | | |
Investment securities (current and long-term): | | |
Marketable Securities | 0 | 0 |
Equity securities | Level 3 | | |
Investment securities (current and long-term): | | |
Marketable Securities | 0 | 0 |
Equity securities | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Marketable Securities | 5 | 7 |
Equity securities | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Marketable Securities | 5 | 7 |
Government mortgage-backed securities | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Government mortgage-backed securities | Level 1 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Government mortgage-backed securities | Level 2 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 43 | 37 |
Government mortgage-backed securities | Level 3 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Government mortgage-backed securities | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 43 | 37 |
Government mortgage-backed securities | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 43 | 37 |
Government bonds | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Government bonds | Level 1 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Government bonds | Level 2 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 30 | 34 |
Government bonds | Level 3 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Government bonds | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 30 | 34 |
Government bonds | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 30 | 34 |
Corporate bonds | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Corporate bonds | Level 1 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Corporate bonds | Level 2 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 30 | 31 |
Corporate bonds | Level 3 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Corporate bonds | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 30 | 31 |
Corporate bonds | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 30 | 31 |
Money market funds | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Money market funds | Level 1 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 19 | 3 |
Money market funds | Level 2 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Money market funds | Level 3 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Money market funds | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 19 | 3 |
Money market funds | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 19 | 3 |
Asset-backed securities | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Asset-backed securities | Level 1 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Asset-backed securities | Level 2 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 15 | 17 |
Asset-backed securities | Level 3 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Asset-backed securities | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 15 | 17 |
Asset-backed securities | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 15 | 17 |
Collateralized Mortgage Backed Securities | Fair Value Measured at Net Asset Value Per Share | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Collateralized Mortgage Backed Securities | Level 1 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Collateralized Mortgage Backed Securities | Level 2 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 1 | 3 |
Collateralized Mortgage Backed Securities | Level 3 | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 0 | 0 |
Collateralized Mortgage Backed Securities | Estimate of Fair Value Measurement | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 1 | 3 |
Collateralized Mortgage Backed Securities | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Trust Assets Fair Value Disclosure | 1 | 3 |
Bank Time Deposits | Carrying Amount, Fair Value Disclosure | | |
Investment securities (current and long-term): | | |
Other Assets, Current | 111 | 103 |
Other assets | $ 135 | 133 |
Fair Value, Recurring [Member] | Forward Contracts | Estimate of Fair Value Measurement | | |
Derivatives: | | |
Derivative Asset | | $ 0 |