Segment Information - Segment Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Mar. 31, 2022
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 6,801,924	$ 6,389,346
Assets of discontinued operations	283,404	275,102
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,002,327	914,558
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	421,343	444,976
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	301,408	202,941
Operating Segments [Member] | Government Systems [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	279,576	266,641
Corporate, Non-Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 5,516,193	$ 5,199,686