Composition of Certain Balance Sheet Captions - Composition of Certain Balance Sheet Captions (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024
Accounts receivable, net:
Accounts receivable, Billed		$ 546,790	$ 545,081
Accounts receivable, Unbilled		173,967	156,322
Allowance for doubtful accounts		(25,868)	(23,193)
Accounts receivable, net		694,889	678,210
Inventories:
Raw materials		100,978	89,778
Work in process		33,153	31,884
Finished goods		195,698	196,216
Inventories		329,829	317,878
Prepaid expenses and other current assets:
Insurance receivable		182,000	261,500
Prepaid expenses		189,525	185,892
Other		119,259	134,391
Prepaid expenses and other current assets		490,784	581,783
Property, equipment and satellites, net:
Property, equipment and satellites, gross		10,856,813	10,651,781
Less: accumulated depreciation and amortization		(3,325,004)	(3,094,575)
Property and equipment, net		7,531,809	7,557,206
Other acquired intangible assets, net:
Other acquired intangible assets, gross		2,912,903	2,917,299
Less: accumulated amortization		(437,411)	(372,832)
Other acquired intangible assets, net		2,475,492	2,544,467
Other assets:
Deferred income taxes		164,909	163,590
Capitalized software costs, net		245,134	240,597
Patents, orbital slots and other licenses, net		115,036	112,535
Other		226,746	217,225
Other assets		751,825	733,947
Accrued and other liabilities:
Collections in excess of revenues and deferred revenues		277,665	260,264
Accrued employee compensation		85,092	177,854
Accrued vacation		49,576	48,636
Operating lease liabilities		$ 69,808	$ 71,561
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]		Accrued and other liabilities	Accrued and other liabilities
Interest payable		$ 75,534	$ 127,098
Other		233,427	265,208
Accrued and other liabilities		791,102	950,621
Other liabilities:
Deferred revenues, long-term portion		878,053	896,402
Deferred income taxes		1,223,012	1,228,270
Other		321,213	327,428
Other liabilities		2,422,278	2,452,100
Contracts and Customer Relationships [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross		1,436,728	1,437,738
Orbital Slots And Spectrum Assets [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross		1,088,600	1,088,600
Technology [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross		248,846	251,889
Trade Names [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross		116,990	117,280
Other [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross		21,739	21,792
Equipment and Software [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		3,051,930	2,992,325
CPE Leased Equipment [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, cost		554,648	567,548
Furniture and Fixtures [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		65,338	65,433
Leasehold Improvements [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		211,668	209,162
Buildings [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		16,649	16,647
Land [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		20,789	20,787
Construction in Progress [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		1,361,156	1,301,376
Satellites [Member]
Prepaid expenses and other current assets:
Insurance receivable	$ 770,000
Property, equipment and satellites, net:
Property, equipment and satellites, gross		3,325,299	3,324,458
Satellite Ka-band Capacity Obtained under Finance Leases [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		177,576	177,576
Satellites under Construction [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross		$ 2,071,760	$ 1,976,469