Segment Reporting - Schedule of Revenue Information by Products and Service Lines (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2025	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenue from External Customer [Line Items]
Revenues	$ 885,842	$ 866,286	$ 764,039	$ 682,258	$ 746,267	$ 671,956	$ 681,465	$ 603,966	$ 3,198,425	$ 2,703,654	$ 2,496,309
Reportable Segments
Revenue from External Customer [Line Items]
Revenues									3,203,160	2,707,012	2,497,681
Reportable Segments \| Government Operations
Revenue from External Customer [Line Items]
Revenues									2,350,090	2,183,040	2,031,337
Reportable Segments \| Government Operations \| Nuclear Components and Fuel
Revenue from External Customer [Line Items]
Revenues									1,796,395	1,692,218	1,610,183
Reportable Segments \| Government Operations \| Uranium Processing and Nuclear Services
Revenue from External Customer [Line Items]
Revenues									406,557	287,014	276,690
Reportable Segments \| Government Operations \| Advanced Reactor Design and Engineering
Revenue from External Customer [Line Items]
Revenues									147,138	203,808	144,464
Reportable Segments \| Commercial Operations
Revenue from External Customer [Line Items]
Revenues									853,070	523,972	466,344
Reportable Segments \| Commercial Operations \| Nuclear Manufacturing
Revenue from External Customer [Line Items]
Revenues									429,223	288,772	231,944
Reportable Segments \| Commercial Operations \| Nuclear Services and Engineering
Revenue from External Customer [Line Items]
Revenues									423,847	235,200	234,400
Eliminations
Revenue from External Customer [Line Items]
Revenues									$ (4,735)	$ (3,358)	$ (1,372)