Composition of Certain Balance Sheet Captions - Composition of Certain Balance Sheet Captions (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Mar. 31, 2024
Accounts receivable, net:
Accounts receivable, Billed	$ 539,522	$ 545,081
Accounts receivable, Unbilled	180,871	156,322
Allowance for doubtful accounts	(20,841)	(23,193)
Accounts receivable, net	699,552	678,210
Inventories:
Raw materials	96,893	89,778
Work in process	19,761	31,884
Finished goods	177,289	196,216
Inventories	293,943	317,878
Prepaid expenses and other current assets:
Insurance receivable	10,000	261,500
Prepaid expenses	176,694	185,892
Other	95,649	134,391
Prepaid expenses and other current assets	282,343	581,783
Property, equipment and satellites, net:
Property, equipment and satellites, gross	11,440,273	10,651,781
Less: accumulated depreciation and amortization	(4,034,609)	(3,094,575)
Property and equipment, net	7,405,664	7,557,206
Other assets:
Deferred income taxes	160,452	163,590
Capitalized software costs, net	264,492	240,597
Patents, orbital slots and other licenses, net	119,193	112,535
Other	301,641	217,225
Other assets	845,778	733,947
Accrued and other liabilities:
Collections in excess of revenues and deferred revenues	294,034	260,264
Accrued employee compensation	185,556	177,854
Accrued vacation	46,651	48,636
Operating lease liabilities	$ 65,310	$ 71,561
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued and other liabilities	Accrued and other liabilities
Interest payable	$ 52,183	$ 127,098
Other	264,795	265,208
Accrued and other liabilities	908,529	950,621
Other liabilities:
Deferred revenues, long-term portion	786,710	896,402
Deferred income taxes	1,069,717	1,228,270
Other	324,726	327,428
Other liabilities	2,181,153	2,452,100
Equipment and Software [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	3,837,083	2,992,325
CPE Leased Equipment [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	525,972	567,548
Furniture and Fixtures [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	58,153	65,433
Leasehold Improvements [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	313,249	209,162
Building [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	15,388	16,647
Land [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	19,661	20,787
Construction in Progress [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	722,194	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	3,405,067	3,324,458
Satellite Ka-band Capacity Obtained under Finance Leases [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	338,201	177,576
Satellites under Construction [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	$ 2,205,305	$ 1,976,469