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Pension and Other Postretirement Benefit Plans - Summary of Changes in Fair Value of Company's Level 3 Pension Plan Assets (Details) - Pension Benefits - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022
Level 3 |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | $ 765 |
Actual return on plan assets: |  |
Fair value of plan assets December 31 | 788 | $ 765
United States |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 9,094 | 13,067
Actual return on plan assets: |  |
Fair value of plan assets December 31 | 9,804 | 9,094
United States | Other |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 4 |
Actual return on plan assets: |  |
Fair value of plan assets December 31 | 3 | 4
United States | Level 3 |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 4 | 6
Actual return on plan assets: |  |
Relating to assets still held at December 31 | (2) | (3)
Relating to assets sold during the year | 2 | 2
Purchases and sales, net | (1) | (1)
Fair value of plan assets December 31 | 3 | 4
United States | Level 3 | Insurance Contracts |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 0 | 0
Actual return on plan assets: |  |
Relating to assets still held at December 31 | 0 | 0
Relating to assets sold during the year | 0 | 0
Purchases and sales, net | 0 | 0
Fair value of plan assets December 31 | 0 | 0
United States | Level 3 | Other |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 4 | 6
Actual return on plan assets: |  |
Relating to assets still held at December 31 | (2) | (3)
Relating to assets sold during the year | 2 | 2
Purchases and sales, net | (1) | (1)
Fair value of plan assets December 31 | 3 | 4
International |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 8,473 | 12,195
Actual return on plan assets: |  |
Fair value of plan assets December 31 | 9,562 | 8,473
International | Insurance Contracts |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 780 |
Actual return on plan assets: |  |
Fair value of plan assets December 31 | 788 | 780
International | Other |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 2 |
Actual return on plan assets: |  |
Fair value of plan assets December 31 | 4 | 2
International | Level 3 |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 761 | 937
Actual return on plan assets: |  |
Relating to assets still held at December 31 | 77 | (147)
Purchases and sales, net | (53) | (39)
Transfers into Level 3 | 0 | 10
Fair value of plan assets December 31 | 785 | 761
International | Level 3 | Insurance Contracts |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 761 | 937
Actual return on plan assets: |  |
Relating to assets still held at December 31 | 77 | (147)
Purchases and sales, net | (53) | (39)
Transfers into Level 3 | 0 | 10
Fair value of plan assets December 31 | 785 | 761
International | Level 3 | Other |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets January 1 | 0 | 0
Actual return on plan assets: |  |
Relating to assets still held at December 31 | 0 | 0
Purchases and sales, net | 0 | 0
Transfers into Level 3 | 0 | 0
Fair value of plan assets December 31 | $ 0 | $ 0

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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 sold. + 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 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(02)(A) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + 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 -SubTopic 20 -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 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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