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Postretirement Health Care and Life Insurance Benefits Details - Textual (Details) - USD ($) $ in Millions |  | 12 Months Ended
--- | --- | ---
Jan. 01, 2026 | Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Total remaining in "Accumulated other comprehensive income" |  | $ 101.1 | $ 138.8 |
Defined Benefit Plan, Equity Securities |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Asset allocation strategy for the Non-Represented trust |  |  | 30.00% |
Fixed Income Securities |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Asset allocation strategy for the Non-Represented trust |  | 100.00% | 70.00% |
Postretirement Health Care and Life Insurance Benefits |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment |  | $ 0.0 | $ 6.5 |
Expected long-term return on plan assets | 4.55% | 5.95% | 5.75% | 5.75%
Defined Benefit Plan, Benefit Obligation |  | $ 130.2 | $ 145.4 | $ 178.0
Defined benefit plan, expected amortization of prior service cost (credit), next fiscal year |  | $ 11.4 |  |
Postretirement Health Care and Life Insurance Benefits | Retirement Plan December 2024 Amendment |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Average remaining service period (in years) |  | 11 years 8 months 12 days | 12 years 8 months 12 days |
Total remaining in "Accumulated other comprehensive income" |  | $ 6.0 |  |
Postretirement Health Care and Life Insurance Benefits | Retirement Plan October 2021 Amendment |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Average remaining service period (in years) |  | 10 years | 11 years |
Total remaining in "Accumulated other comprehensive income" |  | $ 97.8 |  |
Postretirement Health Care and Life Insurance Benefits | Retirement Plan December 2020 Amendment |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Average remaining service period (in years) |  | 5 years 6 months | 6 years 6 months |
Total remaining in "Accumulated other comprehensive income" |  | $ 5.7 |  |
Postretirement Health Care and Life Insurance Benefits | Retirement Plan September 2020 Amendment |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |
Average remaining service period (in years) |  |  | 10 months 24 days |

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- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (j)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-8 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (k)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
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