v3.26.1
Revenue and Contract Balances - Summary of Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Mar. 29, 2026
Mar. 30, 2025
Mar. 29, 2026
Mar. 30, 2025
Disaggregation of Revenue [Line Items]        
Revenue $ 1,220,157 $ 1,322,113 $ 2,430,820 $ 2,742,674
Fixed-price        
Disaggregation of Revenue [Line Items]        
Revenue 587,074 524,950 1,159,516 1,044,772
Time-and-materials        
Disaggregation of Revenue [Line Items]        
Revenue 522,158 605,258 1,065,256 1,204,206
Cost-plus        
Disaggregation of Revenue [Line Items]        
Revenue 110,925 191,905 206,048 493,696
U.S. federal government        
Disaggregation of Revenue [Line Items]        
Revenue 312,120 413,422 584,718 915,270
U.S. state and local government        
Disaggregation of Revenue [Line Items]        
Revenue 176,495 207,438 347,968 410,425
U.S. commercial        
Disaggregation of Revenue [Line Items]        
Revenue 206,843 211,085 432,195 444,676
International        
Disaggregation of Revenue [Line Items]        
Revenue $ 524,699 $ 490,168 $ 1,065,939 $ 972,303