Segment Information - Segment Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Mar. 31, 2023
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 17,072,044	$ 7,730,337
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	5,156,468	1,047,489
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	3,637,061	424,881
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	411,772	328,828
Operating Segments [Member] | Government Systems [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,107,635	293,780
Corporate, Non-Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 11,915,576	$ 6,682,848