Joint Venture with Peabody Energy (Details) - Implementation Agreement - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Jun. 18, 2019
Schedule of Equity Method Investments [Line Items]
Economic interest held		33.50%
Incurred expenses related to regulatory approval process	$ 13.8
Peabody Energy Corporation
Schedule of Equity Method Investments [Line Items]
Economic interest held		66.50%

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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A fee charged for services from professionals such as doctors, lawyers and accountants. The term is often expanded to include other professions, for example, pharmacists charging to maintain a medicinal profile of a client or customer.

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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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