Segment Information - Segment Revenues and Operating Profits (Losses) (Detail) - USD ($) $ in Thousands		3 Months Ended
		Jun. 30, 2025	Jun. 30, 2024
Revenues:
Total revenues		$ 1,171,054	$ 1,126,460
Operating Expenses [Abstract]
Depreciation		257,701	249,800
Stock-based compensation expense		14,707	19,182
Total expenses		1,058,641	1,000,510
Operating profits (losses):
Income (loss) from operations		46,672	59,735
Amortization of acquired intangible assets		(65,741)	(66,215)
Interest income		14,290	22,792
Interest expense		(100,357)	(105,776)
(Loss) gain on extinguishment of debt		(288)	0
Other income (expense), net		(5,164)
Income (loss) before income taxes		(44,847)	(23,249)
Product [Member]
Revenues:
Total revenues		344,684	305,739
Service [Member]
Revenues:
Total revenues		826,370	820,721
Operating Segments [Member]
Operating profits (losses):
Income (loss) from operations		112,413	125,950
Operating Segments [Member] | Communication Services [Member]
Revenues:
Total revenues		827,371	826,787
Operating Expenses [Abstract]
Depreciation		246,749	238,393
Stock-based compensation expense		8,312	12,095
Other than acquired intangible assets amortization	[1]	14,009	10,740
Acquisition and transaction related expenses		7,874	1,786
Other segment items	[2]	509,551	521,834
Total expenses	[3]	786,495	784,848
Operating profits (losses):
Income (loss) from operations		40,876	41,939
Operating Segments [Member] | Communication Services [Member] | Government Satcom Services [Member]
Revenues:
Total revenues		191,768	183,873
Operating Segments [Member] | Communication Services [Member] | Aviation Services [Member]
Revenues:
Total revenues		292,892	257,155
Operating Segments [Member] | Communication Services [Member] | Maritime Services [Member]
Revenues:
Total revenues		117,801	123,947
Operating Segments [Member] | Communication Services [Member] | Fixed Services and Other Services [Member]
Revenues:
Total revenues		174,737	201,636
Operating Segments [Member] | Communication Services [Member] | Product [Member]
Revenues:
Total revenues		50,173	60,176
Operating Segments [Member] | Communication Services [Member] | Service [Member]
Revenues:
Total revenues		777,198	766,611
Operating Segments [Member] | Defense and Advanced Technologies [Member]
Revenues:
Total revenues		343,683	299,673
Operating Expenses [Abstract]
Depreciation		10,952	11,407
Stock-based compensation expense		6,395	7,087
Other than acquired intangible assets amortization	[1]	4,893	4,449
Acquisition and transaction related expenses		1,851	515
Other segment items		248,055	192,204
Total expenses	[3]	272,146	215,662
Operating profits (losses):
Income (loss) from operations		71,537	84,011
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Information Security and Cyber Defense Products [Member]
Revenues:
Total revenues		102,148	55,507
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Space and Mission Systems Products [Member]
Revenues:
Total revenues		87,973	73,306
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Tactical Networking Products [Member]
Revenues:
Total revenues		68,279	71,410
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Advanced Technologies and Other Products [Member]
Revenues:
Total revenues		36,111	45,340
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Product [Member]
Revenues:
Total revenues		294,511	245,563
Operating Segments [Member] | Defense and Advanced Technologies [Member] | Service [Member]
Revenues:
Total revenues		49,172	54,110
Corporate, Non-Segment [Member]
Operating profits (losses):
Amortization of acquired intangible assets		(65,741)	(66,215)
Interest income		14,290	22,792
Interest expense		(100,357)	$ (105,776)
(Loss) gain on extinguishment of debt		(288)
Other income (expense), net		$ (5,164)

[1] Including amortization of capitalized cloud computing implementation costs.

[2] Other segment items include operating expenses such as cost of service and product revenues, selling, general and administrative expenses, IR&D expenses and related activities excluding allocable portion of depreciation, other than acquired intangibles amortization, stock-based compensation, and certain significant items that are disclosed under each segment.

[3] For the three months ended June 30, 2025 and 2024, IR&D expense and related activities, including allocable depreciation, stock-based compensation and other expenses were $19.2 million and $25.8 million, respectively, for the communication services segment, and $15.0 million and $12.8 million, respectively, for the defense and advanced technologies segment.