Fair Value Measurement - Fair Value Measurement Inputs (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Investment securities (current and long-term):
Marketable Securities	$ 0
Other Assets, Current	647	$ 523
Other assets	1,546	1,460
Derivatives:
Derivative Asset	62	73
Derivatives: [Abstract]
Derivative Liability	266	24
Fair Value Measured at Net Asset Value Per Share
Investment securities (current and long-term):
Investments, Fair Value Disclosure	25	29
Trust Assets Fair Value Disclosure	55	64
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	50
Trust Assets Fair Value Disclosure	8	8
Derivatives:
Derivative Asset		10
Discontinued Operation, Contingent Receivable	0	0
Derivatives: [Abstract]
Derivative Liability	43	1
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	115	137
Derivatives:
Derivative Asset		67
Discontinued Operation, Contingent Receivable	0	0
Derivatives: [Abstract]
Derivative Liability	229	27
Long-term debt, including current portion	9,578	10,630
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	60	81
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	79
Trust Assets Fair Value Disclosure	178	209
Derivatives:
Derivative Asset		77
Discontinued Operation, Contingent Receivable	60	81
Derivatives: [Abstract]
Derivative Liability	272	28
Long-term debt, including current portion	9,578	10,630
Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Investments, Fair Value Disclosure	30	79
Trust Assets Fair Value Disclosure	178	209
Derivatives:
Derivative Asset		77
Discontinued Operation, Contingent Receivable	71	90
Derivatives: [Abstract]
Derivative Liability	272	28
Long-term debt, including current portion	10,690	9,450
Embedded Derivative Financial Instruments
Derivatives:
Derivative Asset	62	61
Derivatives: [Abstract]
Derivative Liability	216	24
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	68	64
Derivatives: [Abstract]
Derivative Liability	222	27
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	68	64
Derivatives: [Abstract]
Derivative Liability	222	27
Embedded Derivative Financial Instruments | Carrying Amount, Fair Value Disclosure
Derivatives:
Derivative Asset	68	64
Derivatives: [Abstract]
Derivative Liability	222	27
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	12
Derivatives: [Abstract]
Derivative Liability	50	0
Commodity Contract | Fair Value Measured at Net Asset Value Per Share
Derivatives:
Derivative Asset		0
Commodity Contract | Fair Value Measured at Net Asset Value Per Share | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	0	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		9
Commodity Contract | Level 1 | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	1	1
Commodity Contract | Level 1 | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	42
Commodity Contract | Level 2
Derivatives:
Derivative Asset		3
Commodity Contract | Level 2 | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	0	0
Commodity Contract | Level 2 | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	7
Commodity Contract | Level 3
Derivatives:
Derivative Asset		0
Commodity Contract | Level 3 | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	0	0
Commodity Contract | Level 3 | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	0
Commodity Contract | Estimate of Fair Value Measurement
Derivatives:
Derivative Asset		12
Commodity Contract | Estimate of Fair Value Measurement | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	1	1
Commodity Contract | Estimate of Fair Value Measurement | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	49
Commodity Contract | Carrying Amount, Fair Value Disclosure
Derivatives:
Derivative Asset		12
Commodity Contract | Carrying Amount, Fair Value Disclosure | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	1	1
Commodity Contract | Carrying Amount, Fair Value Disclosure | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	49
U.S. core fixed income fund | Fair Value Measured at Net Asset Value Per Share
Investment securities (current and long-term):
Marketable Securities	25	29
Trust Assets Fair Value Disclosure	55	64
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	29
Trust Assets Fair Value Disclosure	55	64
U.S. core fixed income fund | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Marketable Securities	25	29
Trust Assets Fair Value Disclosure	55	64
Equity securities | Fair Value Measured at Net Asset Value Per Share
Investment securities (current and long-term):
Marketable Securities		0
Equity securities | Level 1
Investment securities (current and long-term):
Marketable Securities	5	50
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	50
Equity securities | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Marketable Securities	5	50
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	35	53
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	35	53
Government bonds | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	35	53
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	33	45
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	33	45
Corporate bonds | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	33	45
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	27	20
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	27	20
Government mortgage-backed securities | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	27	20
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	17	18
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	17	18
Asset-backed securities | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	17	18
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	8	8
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	8	8
Money market funds | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	8	8
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
Collateralized Mortgage Backed Securities | Level 1
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	0
Collateralized Mortgage Backed Securities | Level 2
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	3
Collateralized Mortgage Backed Securities | Level 3
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	0
Collateralized Mortgage Backed Securities | Estimate of Fair Value Measurement
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	3
Collateralized Mortgage Backed Securities | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	3
Municipal bonds | Fair Value Measured at Net Asset Value Per Share
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure		0
Municipal bonds | Level 1
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure		0
Municipal bonds | Level 2
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure		1
Municipal bonds | Level 3
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure		0
Municipal bonds | Estimate of Fair Value Measurement
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure		1
Municipal bonds | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure		1
Bank Time Deposits | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Other Assets, Current	112	114
Other assets	$ 134	132
Fair Value, Recurring [Member] | Forward Contracts | Estimate of Fair Value Measurement
Derivatives:
Derivative Asset		$ 0