Composition of Certain Balance Sheet Captions - Composition of Certain Balance Sheet Captions (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021
Accounts receivable, net:
Accounts receivable, Billed	$ 262,591	$ 172,559
Accounts receivable, Unbilled	105,366	70,785
Allowance for doubtful accounts	(3,463)	(4,692)
Accounts receivable, net	364,494	238,652
Inventories:
Raw materials	94,937	98,338
Work in process	77,400	71,875
Finished goods	177,350	166,459
Inventories	349,687	336,672
Prepaid expenses and other current assets:
Prepaid expenses	101,189	94,405
Other	41,970	25,555
Prepaid expenses and other current assets	143,159	119,960
Property, equipment and satellites, net:
Property, equipment and satellites, gross	5,200,686	4,834,919
Less: accumulated depreciation and amortization	(1,811,243)	(1,784,436)
Property and equipment, net	3,389,443	3,050,483
Other acquired intangible assets, net:
Other acquired intangible assets, gross	391,180	151,549
Less: accumulated amortization	(129,239)	(141,981)
Other acquired intangible assets, net	261,941	9,568
Other assets:
Investment in unconsolidated affiliate		176,938
Deferred income taxes	286,556	273,288
Capitalized software costs, net	232,493	237,100
Patents, orbital slots and other licenses, net	59,307	52,889
Other	105,372	95,212
Other assets	683,728	835,427
Accrued and other liabilities:
Collections in excess of revenues and deferred revenues	201,706	216,594
Accrued employee compensation	42,075	87,153
Accrued vacation	58,606	59,509
Warranty reserve, current portion	7,039	6,693
Operating lease liabilities	$ 50,955	$ 48,896
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued and other liabilities	Accrued and other liabilities
Other	$ 149,648	$ 113,986
Accrued and other liabilities	510,029	532,831
Other liabilities:
Deferred revenues, long-term portion	90,352	84,654
Warranty reserve, long-term portion	5,491	5,193
Satellite performance incentive obligations, long-term portion	21,347	22,191
Other	47,837	25,312
Other liabilities	165,027	137,350
Technology [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	154,246	78,185
Contracts and Customer Relationships [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	177,224	55,161
Satellite Co-Location Rights [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	8,600	8,600
Trade Name [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	32,318	5,940
Other [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	18,792	3,663
Satellites [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	1,065,559	969,952
Satellites under Construction [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	1,497,175	1,338,408
Equipment and Software [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	1,587,674	1,505,697
CPE Leased Equipment [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	409,849	409,942
Less: accumulated depreciation and amortization	(198,900)	(193,700)
Satellite Ka-band Capacity Obtained under Finance Leases [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	173,480	173,467
Furniture and Fixtures [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	59,719	57,433
Leasehold Improvements [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	154,006	149,324
Building [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	12,512	8,923
Land [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	4,008	2,291
Construction in Progress [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	$ 236,704	$ 219,482