Composition of Certain Balance Sheet Captions - Composition of Certain Balance Sheet Captions (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Accounts receivable, net:
Accounts receivable, Billed	$ 144,386	$ 146,309
Accounts receivable, Unbilled	120,181	141,568
Allowance for doubtful accounts	(1,897)	(1,153)
Accounts receivable, net	262,670	286,724
Inventories:
Raw materials	50,171	46,757
Work in process	31,920	27,200
Finished goods	73,420	71,204
Inventories	155,511	145,161
Prepaid expenses and other current assets:
Prepaid expenses	47,987	41,784
Other	5,466	5,799
Prepaid expenses and other current assets	53,453	47,583
Other acquired intangible assets, net:
Other acquired intangible assets, gross	196,840	197,604
Less: accumulated amortization	(165,801)	(164,000)
Other acquired intangible assets, net	31,039	33,604
Other assets:
Deferred income taxes	135,009	134,721
Capitalized software costs, net	176,386	163,061
Patents, orbital slots and other licenses, net	16,800	16,900
Other	33,672	25,323
Other assets	361,867	340,005
Accrued liabilities:
Collections in excess of revenues and deferred revenues	64,576	64,624
Accrued employee compensation	17,681	35,056
Accrued vacation	30,065	28,646
Warranty reserve, current portion	8,263	7,867
Current portion of other long-term debt	277	274
Other	36,032	47,877
Accrued liabilities	156,894	184,344
Other liabilities:
Deferred revenue, long-term portion	5,221	5,470
Deferred rent, long-term portion	9,479	8,808
Warranty reserve, long-term portion	3,894	3,567
Satellite performance incentives obligation, long-term portion	19,334	19,514
Other		12
Other liabilities	37,928	37,371
Technology-Based Intangible Assets [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	74,233	74,848
Contracts and Customer Relationships [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	99,367	99,499
Satellite Co-Location Rights [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	8,600	8,600
Trade Names [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	5,940	5,940
Other Intangible Assets [Member]
Other acquired intangible assets, net:
Other acquired intangible assets, gross	8,700	8,717
Satellites, Net [Member]
Property and equipment, net:
Property and equipment	1,249,616	1,173,880
Less: accumulated depreciation and amortization	(288,364)	(275,683)
Property and equipment, net	961,252	898,197
Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	1,092,986	1,050,886
Less: accumulated depreciation and amortization	(591,341)	(563,976)
Property and equipment, net	501,645	486,910
Satellites [Member] | Satellites, Net [Member]
Property and equipment, net:
Property and equipment	559,094	559,094
Capital Lease of Satellite Capacity - Anik F2 [Member] | Satellites, Net [Member]
Property and equipment, net:
Property and equipment	99,090	99,090
Construction in Progress [Member] | Satellites, Net [Member]
Property and equipment, net:
Property and equipment	591,432	515,696
Construction in Progress [Member] | Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	81,881	73,535
Equipment and Software [Member] | Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	594,447	568,663
CPE Leased Equipment [Member] | Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	264,024	260,409
Less: accumulated depreciation and amortization	(143,200)	(136,400)
Furniture and Fixtures [Member] | Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	28,594	25,501
Leasehold Improvements [Member] | Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	73,157	71,895
Building [Member] | Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	8,923	8,923
Land [Member] | Property and Equipment, Net [Member]
Property and equipment, net:
Property and equipment	$ 41,960	$ 41,960