The Company and a Summary of Its Significant Accounting Policies - Summary of Disaggregation of Revenue by Segment and Product and Services (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Disaggregation Of Revenue [Line Items]
Total revenues	$ 2,787,635	$ 2,256,107	$ 2,309,238
Product [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	1,210,411	1,044,450	1,172,541
Service [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	1,577,224	1,211,657	1,136,697
Operating Segments [Member] | Satellite Services [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	1,188,816	868,943	826,583
Operating Segments [Member] | Satellite Services [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	1,188,816	868,943	826,583
Operating Segments [Member] | Commercial Networks [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	512,099	320,856	344,557
Operating Segments [Member] | Commercial Networks [Member] | Product [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	443,435	268,830	289,959
Operating Segments [Member] | Commercial Networks [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	68,664	52,026	54,598
Operating Segments [Member] | Government Systems [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	1,086,720	1,066,308	1,138,098
Operating Segments [Member] | Government Systems [Member] | Product [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	766,976	775,620	882,582
Operating Segments [Member] | Government Systems [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total revenues	$ 319,744	$ 290,688	$ 255,516