Inventory - Schedule of Inventory (Details) - USD ($) $ in Millions |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Inventory Disclosure [Abstract] | ||
| Coal | $ 73 | $ 94 |
| Oil products | 41 | 57 |
| Fuel inventory for electric generation | 114 | 151 |
| Materials and supplies, net | 128 | 124 |
| Environmental products | 2 | 3 |
| Inventory, net | $ 244 | $ 278 |
| X | ||||||||||
- Definition Inventory, Environmental Products, Net Of Reserves No definition available.
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| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies relating to a source of usable power held for future sale or future use in manufacturing or production process. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Carrying amount as of the balance sheet date of coal, which is a combustible rock or minerals which are extracted from the ground and used as fuel. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Carrying amount as of the balance sheet date of petroleum or crude oil. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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- Definition Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date for elements of machinery or equipment held for the purpose of replacing similar parts in the course of repair or maintenance. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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