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Retirement and Postretirement Plans - Change in Plan Assets (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023
Pension |  |
Change in plan assets: |  |
Fair value of plan assets at the beginning of year | $ 525.6 | $ 549.4
Actual return on plan assets | (1.5) | 31.1
Company contributions / payments | 39.8 | 1.8
Benefits paid | (48.2) | (53.8)
Settlements | (118.2) | (6.0)
Foreign currency translation adjustment | (0.9) | 3.1
Fair value of plan assets at end of year | 396.6 | 525.6
Funded status at end of year | (140.5) | (163.0)
Pension | United States of America | Bargaining Plan |  |
Change in plan assets: |  |
Fair value of plan assets at the beginning of year | 334.7 | 353.9
Actual return on plan assets | 2.8 | 19.3
Company contributions / payments | 40.9 |
Benefits paid | (36.7) | (38.5)
Settlements | 0.0 | 0.0
Fair value of plan assets at end of year | 341.7 | 334.7
Funded status at end of year | (129.9) | (156.2)
Pension | United States of America | Salaried Plan |  |
Change in plan assets: |  |
Fair value of plan assets at the beginning of year | 129.6 | 137.7
Actual return on plan assets | (0.9) | 9.3
Company contributions / payments | (3.6) |
Benefits paid | (6.9) | (11.4)
Settlements | (118.2) | (6.0)
Fair value of plan assets at end of year | 0.0 | 129.6
Funded status at end of year | 0.0 | 5.6
Pension | United States of America | Supplemental Plan |  |
Change in plan assets: |  |
Company contributions / payments | 0.6 | 0.6
Benefits paid | (0.6) | (0.6)
Settlements | 0.0 | 0.0
Funded status at end of year | (16.1) | (16.5)
Pension | United Kingdom | Pension Scheme |  |
Change in plan assets: |  |
Fair value of plan assets at the beginning of year | 61.0 | 57.5
Actual return on plan assets | (3.4) | 2.5
Company contributions / payments | 1.9 | 1.2
Benefits paid | (4.0) | (3.3)
Foreign currency translation adjustment | (0.9) | 3.1
Fair value of plan assets at end of year | 54.6 | 61.0
Funded status at end of year | 5.3 | 4.3
Pension | Mexico | Pension Plan |  |
Change in plan assets: |  |
Fair value of plan assets at the beginning of year | 0.3 | 0.3
Fair value of plan assets at end of year | 0.3 | 0.3
Funded status at end of year | 0.2 | (0.2)
Postretirement |  |
Change in plan assets: |  |
Fair value of plan assets at the beginning of year | 53.8 | 59.2
Actual return on plan assets | 2.7 | 5.3
Company contributions / payments | 2.4 | 1.0
Benefits paid | (9.5) | (11.7)
Fair value of plan assets at end of year | 49.4 | 53.8
Funded status at end of year | $ (30.7) | $ (31.1)

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- Definition Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses. + 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 (b)(1) -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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- Definition Amount of payment to participant under defined benefit plan which decreases plan assets. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 715 -SubTopic 60 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480266/715-60-50-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(5) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
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