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Related Party Transactions - Statement Of Operations Related Party Transactions (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Related Party Transaction [Line Items] |  |  |  |
General and administrative | $ 13,578 | $ 7,787 | $ 22,270 | $ 14,097
Research and development | 26,618 | 15,483 | 49,218 | 26,751
Project development | 27,198 | 869 | 31,687 | 1,291
Related Party |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
General and administrative | 42 | 27 | 69 | 52
Research and development | 20,846 | 12,214 | 39,259 | 20,827
Project development | 19,533 | 0 | 19,533 | 0
Related Party | BHES |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Research and development | 20,178 | 11,819 | 38,005 | 20,165
Project development | 19,533 | 0 | 19,533 | 0
Related Party | Master services agreement administrative costs |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
General and administrative | 42 | 27 | 69 | 52
Related Party | Master services agreement costs for Demonstration Plant |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Research and development | $ 668 | $ 395 | $ 1,254 | $ 662

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- Definition The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1 + Details
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