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, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Mar. 31, 2022
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	$ 211,273		$ 211,273		$ 236,043
Goodwill	162,003		162,003		168,710
Amortization of acquired intangible assets	7,379	$ 7,399	14,902	$ 13,328
Operating Segments [Member] | Satellite Services [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	209,599		209,599		233,740
Goodwill	76,187		76,187		81,972
Amortization of acquired intangible assets	7,088	7,097	14,316	12,419
Operating Segments [Member] | Commercial Networks [Member]
Segment Reporting Information [Line Items]
Goodwill	43,945		43,945		44,050
Operating Segments [Member] | Government Systems [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	1,674		1,674		2,303
Goodwill	41,871		41,871		$ 42,688
Amortization of acquired intangible assets	$ 291	$ 302	$ 586	$ 909