v3.25.2
REVENUE - Revenue by Contract Type (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 27, 2025
Jun. 28, 2024
Jun. 27, 2025
Jun. 28, 2024
Disaggregation of Revenue [Line Items]        
Total revenue $ 1,078,330 $ 1,072,183 $ 2,094,253 $ 2,082,747
Cost-plus and cost-reimbursable        
Disaggregation of Revenue [Line Items]        
Total revenue $ 647,582 615,837 $ 1,270,653 1,200,659
Revenue, percent change 5.20%   5.80%  
Firm-fixed-price        
Disaggregation of Revenue [Line Items]        
Total revenue $ 405,091 429,182 $ 769,177 826,433
Revenue, percent change (5.60%)   (6.90%)  
Time-and-materials        
Disaggregation of Revenue [Line Items]        
Total revenue $ 25,657 $ 27,164 $ 54,423 $ 55,655
Revenue, percent change (5.50%)   (2.20%)