Goodwill and Other Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Goodwill [Line Items]
Goodwill	$ 55.3	$ 55.6
Operating Segments
Goodwill [Line Items]
Goodwill	55.3	55.6
Operating Segments \| Domestic Coke
Goodwill [Line Items]
Goodwill	3.4	3.4
Operating Segments \| Industrial Services
Goodwill [Line Items]
Goodwill	$ 51.9	$ 52.2

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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+ Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details