(Fair Value Measurements Using Significant Unobservable Inputs (Level 3)) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	$ 4,550
Fair value of plan assets, December 31	4,691	$ 4,550
Fixed income \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	7
Fair value of plan assets, December 31	7	7
Derivatives
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	25
Fair value of plan assets, December 31	71	25
Derivatives \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	25
Fair value of plan assets, December 31	71	25
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	8,845	12,075
Fair value of plan assets, December 31	8,836	8,845
U.S. Plans \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	32	(5)
Relating to assets still held at the reporting date	57	29
Relating to assets sold during the period	48	(179)
Purchases, sales and settlements	(59)	187
Transfers in and/or out of Level 3	0	0
Fair value of plan assets, December 31	78	32
U.S. Plans \| Fixed income \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	7	16
Relating to assets still held at the reporting date	0	(9)
Relating to assets sold during the period	0	10
Purchases, sales and settlements	0	(10)
Transfers in and/or out of Level 3	0	0
Fair value of plan assets, December 31	7	7
U.S. Plans \| Derivatives \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, January 1	25	(21)
Relating to assets still held at the reporting date	57	38
Relating to assets sold during the period	48	(189)
Purchases, sales and settlements	(59)	197
Transfers in and/or out of Level 3	0	0
Fair value of plan assets, December 31	$ 71	$ 25

Amount, measured using unobservable inputs, of increase (decrease) in plan assets of defined benefit plan from actual return (loss) on assets sold.

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- Definition

Amount, measured using unobservable inputs, of increase (decrease) in plan assets of defined benefit plan from actual return (loss) on assets still held.

+ References

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480482/715-20-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
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Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
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Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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- Definition

Amount, measured using unobservable input, of increase (decrease) in plan asset of defined benefit plan from purchase, sale and settlement of trade associated with underlying investment.

+ References

+ Details

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- Definition

Amount, measured using unobservable inputs, of increase (decrease) in plan assets of defined benefit plan, for assets transferred into (out of) Level 3 of fair value hierarchy. Includes, but is not limited to, transfer due to change in observability of significant inputs.

+ References

+ Details

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