v3.26.1
REVENUE AND GRANT INCOME RECOGNITION - Schedule of Revenues and Grant Income by Customer Type (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disaggregation of Revenue [Line Items]    
Services revenue [1] $ 39,906 $ 17,091
Total revenues and grant income 43,423 20,804
Cost-based    
Disaggregation of Revenue [Line Items]    
Services revenue 37,413 13,652
Grant income 3,517 3,713
Total revenues and grant income 40,930 17,365
Fixed fee    
Disaggregation of Revenue [Line Items]    
Total revenues and grant income 335 940
Cost plus fixed fee    
Disaggregation of Revenue [Line Items]    
Total revenues and grant income 443 2,108
Time & materials    
Disaggregation of Revenue [Line Items]    
Total revenues and grant income 1,715 391
DOE    
Disaggregation of Revenue [Line Items]    
Services revenue 35,491 11,488
Grant income 3,517 3,713
Total revenues and grant income 39,008 15,201
Department of War    
Disaggregation of Revenue [Line Items]    
Total revenues and grant income 779 1,950
Commercial    
Disaggregation of Revenue [Line Items]    
Total revenues and grant income $ 3,636 $ 3,653
[1] Includes related party revenue of $1.9 million and $2.7 million for the three months ended March 31, 2026 and 2025, respectively.