Segment Information - Segment Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 6,483,355	$ 6,389,346
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,143,591	1,127,083
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	429,644	444,976
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	234,642	202,941
Operating Segments [Member] | Government Systems [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	479,305	479,166
Corporate, Non-Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 5,339,764	$ 5,262,263