v3.26.1
Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disaggregation of Revenue [Line Items]      
Revenue $ 11,217 $ 11,980 $ 10,662
Prime Contractor      
Disaggregation of Revenue [Line Items]      
Revenue 10,513 11,397 10,143
Subcontractor      
Disaggregation of Revenue [Line Items]      
Revenue 704 583 519
Defense Customers      
Disaggregation of Revenue [Line Items]      
Revenue 6,069 5,943 5,061
Intelligence Customers      
Disaggregation of Revenue [Line Items]      
Revenue 1,900 1,867 1,763
National Security Customers      
Disaggregation of Revenue [Line Items]      
Revenue 7,969 7,810 6,824
Civil and Commercial Customers      
Disaggregation of Revenue [Line Items]      
Revenue $ 3,248 $ 4,170 $ 3,838
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%
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%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Defense Customers      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 54.00% 49.00% 47.00%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Intelligence Customers      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 17.00% 16.00% 17.00%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | National Security Customers      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 71.00% 65.00% 64.00%
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Civil and Commercial Customers      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 29.00% 35.00% 36.00%
Revenue from Contract with Customer Benchmark | Contractor Concentration Type Risk      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 100.00% 100.00% 100.00%
Revenue from Contract with Customer Benchmark | Contractor Concentration Type Risk | Prime Contractor      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 94.00% 95.00% 95.00%
Revenue from Contract with Customer Benchmark | Contractor Concentration Type Risk | Subcontractor      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 6.00% 5.00% 5.00%
Cost-reimbursable      
Disaggregation of Revenue [Line Items]      
Revenue $ 6,587 $ 6,865 $ 5,874
Cost-reimbursable | Revenue from Contract with Customer Benchmark | Product Concentration Risk      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 59.00% 57.00% 55.00%
Time-and-materials      
Disaggregation of Revenue [Line Items]      
Revenue $ 2,492 $ 2,707 $ 2,530
Time-and-materials | Revenue from Contract with Customer Benchmark | Product Concentration Risk      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 22.00% 23.00% 24.00%
Fixed-price      
Disaggregation of Revenue [Line Items]      
Revenue $ 2,138 $ 2,408 $ 2,258
Fixed-price | Revenue from Contract with Customer Benchmark | Product Concentration Risk      
Disaggregation of Revenue [Line Items]      
Concentration risk (as a percent) 19.00% 20.00% 21.00%