Segment Information - Segment Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Mar. 31, 2023
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 16,650,655	$ 7,730,337
Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	5,415,432	1,047,489
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	3,729,631	424,881
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	404,705	328,828
Operating Segments [Member] | Government Systems [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,281,096	293,780
Corporate, Non-Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 11,235,223	$ 6,682,848