Segment Information - Segment Revenues and Operating Profits (Losses) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Revenues:
Total revenues	$ 1,128,539	$ 651,444	$ 3,133,745	$ 1,890,059
Operating profits (losses):
Income (loss) from operations	(43,918)	(31,311)	(890,101)	(83,264)
Amortization of acquired intangible assets	(91,719)	(7,433)	(200,904)	(22,335)
Product [Member]
Revenues:
Total revenues	303,073	249,315	941,174	682,769
Service [Member]
Revenues:
Total revenues	825,466	402,129	2,192,571	1,207,290
Operating Segments [Member]
Operating profits (losses):
Income (loss) from operations	47,801	(23,878)	(689,197)	(60,929)
Operating Segments [Member] | Satellite Services [Member]
Revenues:
Total revenues	581,429	302,412	1,565,247	915,059
Operating profits (losses):
Income (loss) from operations	41,115	(8,421)	(779,493)	(13,142)
Amortization of acquired intangible assets	(80,328)	(7,142)	(179,151)	(21,458)
Operating Segments [Member] | Satellite Services [Member] | Service [Member]
Revenues:
Total revenues	581,429	302,412	1,565,247	915,059
Operating Segments [Member] | Commercial Networks [Member]
Revenues:
Total revenues	166,360	167,223	590,153	460,034
Operating profits (losses):
Income (loss) from operations	(70,343)	(40,266)	(73,972)	(90,442)
Operating Segments [Member] | Commercial Networks [Member] | Product [Member]
Revenues:
Total revenues	144,525	147,163	523,517	400,569
Operating Segments [Member] | Commercial Networks [Member] | Service [Member]
Revenues:
Total revenues	21,835	20,060	66,636	59,465
Operating Segments [Member] | Government Systems [Member]
Revenues:
Total revenues	380,750	181,809	978,345	514,966
Operating profits (losses):
Income (loss) from operations	77,029	24,809	164,268	42,655
Amortization of acquired intangible assets	(11,391)	(291)	(21,753)	(877)
Operating Segments [Member] | Government Systems [Member] | Product [Member]
Revenues:
Total revenues	158,548	102,152	417,657	282,200
Operating Segments [Member] | Government Systems [Member] | Service [Member]
Revenues:
Total revenues	222,202	79,657	560,688	232,766
Material Reconciling Items [Member]
Operating profits (losses):
Amortization of acquired intangible assets	$ (91,719)	$ (7,433)	$ (200,904)	$ (22,335)