v3.26.3
Basis of Presentation - Summary of Disaggregation of Revenue by Segment and Products and Services (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Disaggregation Of Revenue [Line Items]        
Total revenues $ 1,179,996 $ 1,140,893 $ 2,336,539 $ 2,311,947
Service [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues 820,595 821,510 1,653,033 1,647,880
Product [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues 359,401 319,383 683,506 664,067
Operating Segments [Member] | Communication Services [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues 814,526 836,655 1,639,609 1,664,026
Operating Segments [Member] | Communication Services [Member] | Service [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues 758,136 769,817 1,531,178 1,547,015
Operating Segments [Member] | Communication Services [Member] | Product [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues 56,390 66,838 108,431 117,011
Operating Segments [Member] | Defense and Advanced Technologies [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues 365,470 304,238 696,930 647,921
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Service [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues 62,459 51,693 121,855 100,865
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Product [Member]        
Disaggregation Of Revenue [Line Items]        
Total revenues $ 303,011 $ 252,545 $ 575,075 $ 547,056