Basis of Presentation - Additional Information (Detail)		3 Months Ended		6 Months Ended
	Oct. 06, 2015 USD ($) a	Sep. 30, 2015 USD ($)	Oct. 03, 2014 USD ($)	Sep. 30, 2015 USD ($)	Oct. 03, 2014 USD ($)	Jun. 30, 2015 USD ($)	Apr. 03, 2015 USD ($)
Company And Summary Of Significant Accounting Policies [Line Items]
Forward loss related to loss contracts		$ 300,000	$ 0	$ 1,700,000	$ 100,000
Defense contract audit agency completed cost audits				Contract costs on U.S. government contracts are subject to audit and review by the Defense Contracting Management Agency (DCMA), the Defense Contract Audit Agency (DCAA), and other U.S. government agencies, as well as negotiations with U.S. government representatives. The Company's incurred cost audits by the DCAA have not been concluded for fiscal year 2015. As of September 30, 2015, the DCAA had completed its incurred cost audit for fiscal year 2004 and approved the Company's incurred cost claims for fiscal years 2005 through 2014 without further audit. Although the Company has recorded contract revenues subsequent to fiscal year 2014 based upon an estimate of costs that the Company believes will be approved upon final audit or review, the Company does not know the outcome of any ongoing or future audits or reviews and adjustments, and if future adjustments exceed the Company's estimates, its profitability would be adversely affected.
Advertising expenses		2,900,000	5,000,000	$ 6,600,000	7,300,000
Capitalized interest expense		7,100,000	3,600,000	13,200,000	6,700,000
Total capitalized costs related to patents		3,200,000		3,200,000			$ 3,200,000
Total capitalized costs related to orbital slots and other licenses		15,200,000		15,200,000			15,100,000
Accumulated amortization of patents and other licenses		1,500,000		1,500,000			1,400,000
Write off costs due to abandonment or impairment		0	0	0	0
Amortization expense related to patents and other licenses		0	0	0	0
Capitalized debt issuance costs		0	$ 0	0	$ 0
Property Plant and Equipment - Excluding Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property and equipment		942,215,000		942,215,000			878,550,000
Accumulated depreciation and amortization		515,264,000		515,264,000			460,528,000
CPE leased equipment [Member] | Property Plant and Equipment - Excluding Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property and equipment		256,027,000		256,027,000			250,281,000
Accumulated depreciation and amortization		122,300,000		$ 122,300,000			107,800,000
Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)				2 years
Minimum [Member] | CPE leased equipment [Member] | Property Plant and Equipment - Excluding Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)				4 years
Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)				24 years
Maximum [Member] | CPE leased equipment [Member] | Property Plant and Equipment - Excluding Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)				5 years
Subsequent Event [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Number of acres land purchased | a	23
Purchased land value at cost	$ 39,500,000
Unfavorable Regulatory Action [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Total U.S. government contract-related reserves balance		$ 2,900,000		$ 2,900,000			$ 4,300,000
Engreen [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Purchase price of the acquisition						$ 5,000,000
Purchase price of the acquisition that has been withheld						$ 1,000,000