Fair Value Measurement - Fair Value Measurement Inputs (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Investment securities (current and long-term):
Marketable Securities	$ 0
Other Assets, Current	608	$ 523
Other assets	1,501	1,460
Derivatives:
Derivative Asset	49	73
Derivatives: [Abstract]
Derivative Liability	542	24
Fair Value Measured at Net Asset Value Per Share
Investment securities (current and long-term):
Investments, Fair Value Disclosure	26	29
Trust Assets Fair Value Disclosure	56	64
Derivatives:
Derivative Asset	0	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	8	10
Discontinued Operation, Contingent Receivable	0	0
Derivatives: [Abstract]
Derivative Liability	64	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	122	137
Derivatives:
Derivative Asset	45	67
Discontinued Operation, Contingent Receivable	0	0
Derivatives: [Abstract]
Derivative Liability	482	27
Long-term debt, including current portion	10,601	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	0
Discontinued Operation, Contingent Receivable	67	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	31	79
Trust Assets Fair Value Disclosure	186	209
Derivatives:
Derivative Asset	53	77
Discontinued Operation, Contingent Receivable	67	81
Derivatives: [Abstract]
Derivative Liability	546	28
Long-term debt, including current portion	10,601	10,630
Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Investments, Fair Value Disclosure	31	79
Trust Assets Fair Value Disclosure	186	209
Derivatives:
Derivative Asset	53	77
Discontinued Operation, Contingent Receivable	79	90
Derivatives: [Abstract]
Derivative Liability	546	28
Long-term debt, including current portion	11,092	9,450
Embedded Derivative Financial Instruments
Derivatives:
Derivative Asset	38	61
Derivatives: [Abstract]
Derivative Liability	476	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	38	64
Derivatives: [Abstract]
Derivative Liability	476	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	38	64
Derivatives: [Abstract]
Derivative Liability	476	27
Embedded Derivative Financial Instruments | Carrying Amount, Fair Value Disclosure
Derivatives:
Derivative Asset	38	64
Derivatives: [Abstract]
Derivative Liability	476	27
Forward Contracts | Level 1
Derivatives:
Derivative Asset	8	1
Forward Contracts | Level 2
Derivatives:
Derivative Asset	7	0
Forward Contracts | Level 3
Derivatives:
Derivative Asset	0	0
Forward Contracts | Estimate of Fair Value Measurement
Derivatives:
Derivative Asset	15	1
Forward Contracts | Carrying Amount, Fair Value Disclosure
Derivatives:
Derivative Asset	15	1
Commodity Contract
Derivatives:
Derivative Asset	11	12
Derivatives: [Abstract]
Derivative Liability	66	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	3	1
Commodity Contract | Level 1 | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	61
Commodity Contract | Level 2
Derivatives:
Derivative Asset		3
Commodity Contract | Level 2 | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	1	0
Commodity Contract | Level 2 | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	5
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	4	1
Commodity Contract | Estimate of Fair Value Measurement | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	66
Commodity Contract | Carrying Amount, Fair Value Disclosure
Derivatives:
Derivative Asset		12
Commodity Contract | Carrying Amount, Fair Value Disclosure | Forward Contracts
Derivatives: [Abstract]
Derivative Liability	4	1
Commodity Contract | Carrying Amount, Fair Value Disclosure | Futures and Swaps
Derivatives: [Abstract]
Derivative Liability	66
U.S. core fixed income fund | Fair Value Measured at Net Asset Value Per Share
Investment securities (current and long-term):
Marketable Securities	26	29
Trust Assets Fair Value Disclosure	56	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	26	29
Trust Assets Fair Value Disclosure	56	64
U.S. core fixed income fund | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Marketable Securities	26	29
Trust Assets Fair Value Disclosure	56	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	39	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	39	53
Government bonds | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	39	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	36	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	36	45
Corporate bonds | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	36	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	28	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	28	20
Government mortgage-backed securities | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	28	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	16	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	16	18
Asset-backed securities | Carrying Amount, Fair Value Disclosure
Investment securities (current and long-term):
Trust Assets Fair Value Disclosure	16	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	119	114
Other assets	134	132
Fair Value, Recurring [Member] | Forward Contracts | Estimate of Fair Value Measurement
Derivatives:
Derivative Asset	$ 0	$ 0