v3.26.3
Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Disaggregation of Revenue [Line Items]        
Revenue $ 2,778 $ 2,890 $ 5,578 $ 5,814
Revenue from Contract with Customer Benchmark | Product Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 100.00% 100.00% 100.00% 100.00%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 100.00% 100.00% 100.00% 100.00%
Revenue from Contract with Customer Benchmark | Contractor Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 100.00% 100.00% 100.00% 100.00%
Prime Contractor        
Disaggregation of Revenue [Line Items]        
Revenue $ 2,621 $ 2,701 $ 5,272 $ 5,442
Prime Contractor | Revenue from Contract with Customer Benchmark | Contractor Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 94.00% 93.00% 95.00% 94.00%
Subcontractor        
Disaggregation of Revenue [Line Items]        
Revenue $ 157 $ 189 $ 306 $ 372
Subcontractor | Revenue from Contract with Customer Benchmark | Contractor Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 6.00% 7.00% 5.00% 6.00%
National Security        
Disaggregation of Revenue [Line Items]        
Revenue $ 2,076 $ 2,063 $ 4,104 $ 4,064
National Security | Revenue from Contract with Customer Benchmark | Customer Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 75.00% 71.00% 74.00% 70.00%
Civil and Commercial        
Disaggregation of Revenue [Line Items]        
Revenue $ 702 $ 827 $ 1,474 $ 1,750
Civil and Commercial | Revenue from Contract with Customer Benchmark | Customer Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 25.00% 29.00% 26.00% 30.00%
Cost-reimbursable        
Disaggregation of Revenue [Line Items]        
Revenue $ 1,638 $ 1,713 $ 3,245 $ 3,471
Cost-reimbursable | Revenue from Contract with Customer Benchmark | Product Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 59.00% 59.00% 58.00% 60.00%
Time-and-materials        
Disaggregation of Revenue [Line Items]        
Revenue $ 580 $ 638 $ 1,196 $ 1,276
Time-and-materials | Revenue from Contract with Customer Benchmark | Product Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 21.00% 22.00% 22.00% 22.00%
Fixed-price        
Disaggregation of Revenue [Line Items]        
Revenue $ 560 $ 539 $ 1,137 $ 1,067
Fixed-price | Revenue from Contract with Customer Benchmark | Product Concentration Risk        
Disaggregation of Revenue [Line Items]        
Concentration risk (as a percent) 20.00% 19.00% 20.00% 18.00%