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Employee Benefits - Benefit Obligations and Funded Status of Pension Plans, OPEB and Salaried VEBAs (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Salaried VEBA |  |  |
Change in benefit obligation: |  |  |
Obligation at beginning of year | $ 78.3 | $ 90.2 |
Service cost | 0.1 | 0.1 |
Interest cost | 1.5 | 2.5 |
Prior service cost (credit) | 14.0 | (12.3) |
Actuarial (gain) loss | (6.9) | 4.7 |
Benefits paid | (7.2) | (6.9) |
Obligation at end of year | 79.8 | 78.3 | $ 90.2
Change in plan assets: |  |  |
Fair market value of plan assets at beginning of year | 60.5 | 57.6 |
Actual return on assets | 5.9 | 8.1 |
Company contributions |  | 1.7 |
Benefits paid | (7.2) | (6.9) |
Fair market value of plan assets at end of year | 59.2 | 60.5 | 57.6
Net funded status | (20.6) | (17.8) |
Cumulative loss recognized in Accumulated Other Comprehensive: |  |  |
Accumulated net actuarial loss | (1.2) | (11.2) |
Prior service cost | (34.6) | (24.1) |
Total | (35.8) | (35.3) |
Pension Plan |  |  |
Change in benefit obligation: |  |  |
Obligation at beginning of year | 10.0 | 8.8 |
Obligation assumed through acquisition of Warrick | 6.5 |  |
Foreign currency translation adjustment |  | 0.3 |
Service cost | 4.1 | 0.3 | 0.3
Interest cost | 0.5 | 0.3 | 0.3
Actuarial (gain) loss | (0.3) | 0.6 |
Benefits paid | (0.5) | (0.3) |
Obligation at end of year | 20.3 | 10.0 | 8.8
Change in plan assets: |  |  |
Fair market value of plan assets at beginning of year | 8.7 | 7.8 |
Foreign currency translation adjustment |  | 0.2 |
Actual return on assets | 1.1 | 0.7 |
Company contributions | 0.5 | 0.3 |
Benefits paid | (0.5) | (0.3) |
Fair market value of plan assets at end of year | 9.8 | 8.7 | $ 7.8
Net funded status | (10.5) | (1.3) |
Cumulative loss recognized in Accumulated Other Comprehensive: |  |  |
Accumulated net actuarial loss | (1.0) | (2.1) |
Total | (1.0) | $ (2.1) |
Other Postretirement Benefits Plan |  |  |
Change in benefit obligation: |  |  |
Obligation assumed through acquisition of Warrick | 78.1 |  |
Service cost | 1.1 |  |
Interest cost | 1.7 |  |
Actuarial (gain) loss | 2.6 |  |
Obligation at end of year | 83.5 |  |
Change in plan assets: |  |  |
Net funded status | (83.5) |  |
Cumulative loss recognized in Accumulated Other Comprehensive: |  |  |
Accumulated net actuarial loss | (2.6) |  |
Total | $ (2.6) |  |

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- Definition Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (j) -URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=124509347&loc=SL7669686-108580 + Details
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