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v3.26.1

Segment Information - Revenue from External Customers (Details) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2026 USD ($) customer | Jun. 30, 2025 USD ($) customer | Jun. 30, 2026 USD ($) customer | Jun. 30, 2025 USD ($) customer
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] |  |  |  |
Revenues | $ 491,505 | $ 548,675 | $ 1,015,038 | $ 1,078,342
Total revenues | $ 492,856 | $ 550,274 | $ 1,017,843 | $ 1,082,231
Revenues | Customer Concentration Risk |  |  |  |
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] |  |  |  |
Number of customers exceeding 10% of total trade accounts receivable, net | customer | 2 | 3 | 3 | 4
Revenues | Customer Concentration Risk | Top Customer |  |  |  |
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] |  |  |  |
Concentration risk (as a percent) | 15.00% | 16.00% | 13.00% | 14.00%
Revenues | Customer Concentration Risk | Top 10 Customers |  |  |  |
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] |  |  |  |
Concentration risk (as a percent) | 73.00% | 80.00% | 76.00% | 80.00%
Accounts Receivable | Customer Concentration Risk |  |  |  |
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] |  |  |  |
Number of customers exceeding 10% of total trade accounts receivable, net | customer |  |  | 3 | 3
Export Coal Revenue |  |  |  |
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] |  |  |  |
Revenues | $ 353,683 | $ 394,979 | $ 757,104 | $ 790,694
Export Coal Revenue | Revenues | Geographic Concentration Risk |  |  |  |
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Line Items] |  |  |  |
Concentration risk (as a percent) | 72.00% | 72.00% | 75.00% | 73.00%

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