Segment Information - Segment Revenues and Operating Profits (Losses) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues:
Total revenues	$ 1,225,415	$ 663,559	$ 2,005,206	$ 1,238,615
Operating profits (losses):
Income (loss) from operations	(804,667)	4,685	(846,183)	(51,953)
Amortization of acquired intangible assets	(81,374)	(7,379)	(109,185)	(14,902)
Product [Member]
Revenues:
Total revenues	401,729	260,959	638,101	433,454
Service [Member]
Revenues:
Total revenues	823,686	402,600	1,367,105	805,161
Operating Segments [Member]
Operating profits (losses):
Income (loss) from operations	(723,293)	12,064	(736,998)	(37,051)
Operating Segments [Member] | Satellite Services [Member]
Revenues:
Total revenues	585,334	300,547	983,818	612,647
Operating profits (losses):
Income (loss) from operations	(832,046)	(6,066)	(820,608)	(4,721)
Amortization of acquired intangible assets	(77,172)	(7,088)	(98,823)	(14,316)
Operating Segments [Member] | Satellite Services [Member] | Service [Member]
Revenues:
Total revenues	585,334	300,547	983,818	612,647
Operating Segments [Member] | Commercial Networks [Member]
Revenues:
Total revenues	275,198	180,027	423,793	292,811
Operating profits (losses):
Income (loss) from operations	43,083	(796)	(3,629)	(50,176)
Operating Segments [Member] | Commercial Networks [Member] | Product [Member]
Revenues:
Total revenues	251,111	159,831	378,992	253,406
Operating Segments [Member] | Commercial Networks [Member] | Service [Member]
Revenues:
Total revenues	24,087	20,196	44,801	39,405
Operating Segments [Member] | Government Systems [Member]
Revenues:
Total revenues	364,883	182,985	597,595	333,157
Operating profits (losses):
Income (loss) from operations	65,670	18,926	87,239	17,846
Amortization of acquired intangible assets	(4,202)	(291)	(10,362)	(586)
Operating Segments [Member] | Government Systems [Member] | Product [Member]
Revenues:
Total revenues	150,618	101,128	259,109	180,048
Operating Segments [Member] | Government Systems [Member] | Service [Member]
Revenues:
Total revenues	214,265	81,857	338,486	153,109
Material Reconciling Items [Member]
Operating profits (losses):
Amortization of acquired intangible assets	$ (81,374)	$ (7,379)	$ (109,185)	$ (14,902)