Composition of Certain Balance Sheet Captions - Composition of Certain Balance Sheet Captions (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Mar. 31, 2020
Accounts receivable, net:
Accounts receivable, Billed	$ 172,559	$ 260,431
Accounts receivable, Unbilled	70,785	75,661
Allowance for doubtful accounts	(4,692)	(5,394)
Accounts receivable, net	238,652	330,698
Inventories:
Raw materials	98,338	83,353
Work in process	71,875	59,429
Finished goods	166,459	151,634
Inventories	336,672	294,416
Prepaid expenses and other current assets:
Prepaid expenses	94,405	84,872
Other	25,555	31,409
Prepaid expenses and other current assets	119,960	116,281
Property, equipment and satellites, net:
Property, equipment and satellites, gross	4,834,919	4,101,634
Less: accumulated depreciation and amortization	(1,784,436)	(1,514,899)
Property and equipment, net	3,050,483	2,586,735
Other assets:
Investment in unconsolidated affiliate	176,938	160,204
Deferred income taxes	273,288	276,331
Capitalized software costs, net	237,100	242,741
Patents, orbital slots and other licenses, net	52,889	39,135
Other	95,212	88,941
Other assets	835,427	807,352
Accrued and other liabilities:
Collections in excess of revenues and deferred revenues	216,594	123,019
Accrued employee compensation	87,153	72,654
Accrued vacation	59,509	48,963
Warranty reserve, current portion	6,693	6,233
Operating lease liabilities	$ 48,896	$ 42,146
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued and other liabilities	Accrued and other liabilities
Other	$ 113,986	$ 98,175
Accrued and other liabilities	532,831	391,190
Other liabilities:
Deferred revenues, long-term portion	84,654	80,802
Warranty reserve, long-term portion	5,193	5,410
Satellite performance incentive obligations, long-term portion	22,191	24,349
Other	25,312	10,373
Other liabilities	137,350	120,934
Satellites [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	969,952	969,952
Satellites under Construction [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	1,338,408	906,720
Equipment and Software [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	1,505,697	1,229,926
CPE Leased Equipment [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	409,942	399,343
Less: accumulated depreciation and amortization	(193,700)	(165,700)
Satellite Ka-band Capacity Obtained under Finance Leases [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	173,467	171,801
Furniture and Fixtures [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	57,433	54,688
Leasehold Improvements [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	149,324	137,287
Building [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	8,923	8,923
Land [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	2,291	2,291
Construction in Progress [Member]
Property, equipment and satellites, net:
Property, equipment and satellites, gross	$ 219,482	$ 220,703