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Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Millions | 9 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | Dec. 31, 2023 | [3]
Supplemental Cash Flow Elements [Abstract] |  |  |  |  |  |
Interest paid | $ 33.3 | $ 30.5 |  |  |  |
Non-cash investing and financing activities (included in Accounts payable): |  |  |  |  |  |
Unpaid purchases of property and equipment | 23.5 | 24.7 |  |  |  |
Supplemental lease disclosures: |  |  |  |  |  |
Operating lease liabilities arising from obtaining operating lease assets | 1.9 | 0.9 |  |  |  |
Cash paid for amounts included in the measurement of operating lease liabilities | 5.2 | 6.1 |  |  |  |
Finance lease liabilities arising from obtaining finance lease assets | 1.7 | 2.6 |  |  |  |
Components of cash, cash equivalents and restricted cash: |  |  |  |  |  |
Cash and cash equivalents | 17.2 | 45.7 |  | $ 18.4 | [1] |
Restricted cash included in Other assets | 19.8 | 18.3 |  | 19.5 | [2] |
Total cash, cash equivalents and restricted cash presented on our Statements of Consolidated Cash Flows | $ 37.0 | $ 64.0 | [3] | $ 37.9 |  | $ 100.7
[1] | Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 14 for further discussion.
[2] | Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 14 for further discussion.
[3] | Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 14 for further discussion.

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- Definition Amount of cash and cash equivalent. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483467/210-10-45-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-4 + Details
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- Definition Amount of cash and cash equivalent, and cash and cash equivalent restricted to withdrawal or usage; attributable to continuing operation. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-8 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-24 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-4 + Details
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- Definition Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 17 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 25 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-25 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-2 + Details
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