Segment Information - Segment Revenues and Operating Profits (Losses) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Revenues:
Total revenues	$ 678,223	$ 664,860
Operating profits (losses):
Income (loss) from operations	(27,062)	16,292
Amortization of acquired intangible assets	(7,523)	(5,929)
Product [Member]
Revenues:
Total revenues	268,800	293,264
Service [Member]
Revenues:
Total revenues	409,423	371,596
Operating Segments [Member]
Operating profits (losses):
Income (loss) from operations	19,539	22,221
Operating Segments [Member] | Satellite Services [Member]
Revenues:
Total revenues	312,100	274,117
Operating profits (losses):
Income (loss) from operations	3,500	12,513
Amortization of acquired intangible assets	(7,228)	(5,322)
Operating Segments [Member] | Satellite Services [Member] | Service [Member]
Revenues:
Total revenues	312,100	274,117
Operating Segments [Member] | Commercial Networks [Member]
Revenues:
Total revenues	112,784	118,596
Operating profits (losses):
Income (loss) from operations	(42,397)	(37,708)
Operating Segments [Member] | Commercial Networks [Member] | Product [Member]
Revenues:
Total revenues	93,575	101,531
Operating Segments [Member] | Commercial Networks [Member] | Service [Member]
Revenues:
Total revenues	19,209	17,065
Operating Segments [Member] | Government Systems [Member]
Revenues:
Total revenues	253,339	272,147
Operating profits (losses):
Income (loss) from operations	19,358	47,416
Amortization of acquired intangible assets	(295)	(607)
Operating Segments [Member] | Government Systems [Member] | Product [Member]
Revenues:
Total revenues	175,225	191,733
Operating Segments [Member] | Government Systems [Member] | Service [Member]
Revenues:
Total revenues	78,114	80,414
Material Reconciling Items [Member]
Operating profits (losses):
Amortization of acquired intangible assets	$ (7,523)	$ (5,929)