Composition of Certain Balance Sheet Captions - Composition of Certain Balance Sheet Captions (Detail) - USD ($) $ in Thousands	Jun. 30, 2025	Mar. 31, 2025
Accounts receivable, net:
Accounts receivable, Billed	$ 527,033	$ 539,522
Accounts receivable, Unbilled	180,411	180,871
Allowance for doubtful accounts	(21,259)	(20,841)
Accounts receivable, net	686,185	699,552
Inventories:
Raw materials	95,978	96,893
Work in process	21,997	19,761
Finished goods	166,241	177,289
Inventories	284,216	293,943
Prepaid expenses and other current assets:
Prepaid expenses	174,435	176,694
Other	133,477	105,649
Prepaid expenses and other current assets	307,912	282,343
Property, equipment and satellites, net:
Property, equipment and satellites, gross	11,627,598	11,440,273
Less: accumulated depreciation and amortization	(4,288,128)	(4,034,609)
Property and equipment, net	7,339,470	7,405,664
Acquired intangible assets, net:
Acquired intangible assets, gross	2,879,415	2,904,049
Less: accumulated amortization	(687,641)	(633,272)
Acquired intangible assets, net	2,191,774	2,270,777
Other assets:
Deferred income taxes	148,766	160,452
Capitalized software costs, net	264,813	264,492
Patents, orbital slots and other licenses, net	126,206	119,193
Other	313,272	301,641
Other assets	853,057	845,778
Accrued and other liabilities:
Collections in excess of revenues and deferred revenues	298,876	294,034
Accrued employee compensation	88,257	185,556
Accrued vacation	48,323	46,651
Operating lease liabilities	$ 67,297	$ 65,310
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued and other liabilities	Accrued and other liabilities
Interest payable	$ 79,045	$ 52,183
Other	285,518	264,795
Accrued and other liabilities	867,316	908,529
Other liabilities:
Deferred revenues, long-term portion	779,444	786,710
Deferred income taxes	1,068,545	1,069,717
Other	318,459	324,726
Other liabilities	2,166,448	2,181,153
Contracts and Customer Relationships [Member]
Acquired intangible assets, net:
Acquired intangible assets, gross	1,433,043	1,432,562
Orbital Slots And Spectrum Assets [Member]
Acquired intangible assets, net:
Acquired intangible assets, gross	1,088,600	1,088,600
Technology [Member]
Acquired intangible assets, net:
Acquired intangible assets, gross	224,571	247,921
Trade Names [Member]
Acquired intangible assets, net:
Acquired intangible assets, gross	114,587	116,949
Other [Member]
Acquired intangible assets, net:
Acquired intangible assets, gross	18,614	18,017
Equipment and Software [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	3,941,901	3,837,083
CPE Leased Equipment [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, cost	524,974	525,972
Furniture and Fixtures [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	58,112	58,153
Leasehold Improvements [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	315,333	313,249
Buildings [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	15,388	15,388
Land [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	19,661	19,661
Construction in Progress [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	732,318	722,194
Satellites [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	3,412,660	3,405,067
Satellite Ka-band Capacity Obtained under Finance Leases [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	338,201	338,201
Satellites under Construction [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	$ 2,269,050	$ 2,205,305