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		6 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2023
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	$ 2,771,837		$ 2,771,837		$ 201,205
Goodwill	1,375,542		1,375,542		158,542
Amortization of acquired intangible assets	81,374	$ 7,379	109,185	$ 14,902
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	2,441,089		2,441,089		200,097
Goodwill	891,681		891,681		80,589
Amortization of acquired intangible assets	77,172	7,088	98,823	14,316
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting Information [Line Items]
Goodwill	41,021		41,021		41,014
Operating Segments [Member] | Government Systems [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	330,748		330,748		1,108
Goodwill	442,840		442,840		$ 36,939
Amortization of acquired intangible assets	$ 4,202	$ 291	$ 10,362	$ 586