Segment Information - Other Acquired Intangible Assets, Net and Goodwill Included in Segment Assets and Amortization of Acquired Intangible Assets by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2023
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	$ 2,773,665		$ 2,773,665		$ 201,205
Goodwill	1,613,706		1,613,706		158,542
Amortization of acquired intangible assets	91,719	$ 7,433	200,904	$ 22,335
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	2,375,977		2,375,977		200,097
Goodwill	1,050,740		1,050,740		80,589
Amortization of acquired intangible assets	80,328	7,142	179,151	21,458
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting Information [Line Items]
Goodwill	41,188		41,188		41,014
Operating Segments [Member] | Government Systems [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	397,688		397,688		1,108
Goodwill	521,778		521,778		$ 36,939
Amortization of acquired intangible assets	$ 11,391	$ 291	$ 21,753	$ 877