Senior Notes and Other Long-Term Debt - Additional Information (Detail) $ in Thousands	6 Months Ended
	Sep. 30, 2015 USD ($) Installment	Apr. 03, 2015 USD ($)	Oct. 31, 2012 USD ($)	Feb. 27, 2012 USD ($)
Revolving credit facility [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity	$ 500,000
Maturity date of the Credit Facility	Nov. 26, 2018
Credit Facility interest rate description	Borrowings under the Revolving Credit Facility bear interest, at the Company’s option, at either (1) the highest of the Federal Funds rate plus 0.50%, the Eurodollar rate plus 1.00%, or the administrative agent’s prime rate as announced from time to time, or (2) the Eurodollar rate, plus, in the case of each of (1) and (2), an applicable margin that is based on the Company’s total leverage ratio.
Weighted average effective interest rate on the Company's outstanding borrowings under the Credit Facility	2.21%
Credit facility description	The Revolving Credit Facility contains financial covenants regarding a maximum total leverage ratio and a minimum interest coverage ratio. In addition, the Revolving Credit Facility contains covenants that restrict, among other things, the Company’s ability to sell assets, make investments and acquisitions, make capital expenditures, grant liens, pay dividends and make certain other restricted payments.
Borrowing availability under the Credit Facility	$ 288,800
Principal amount of outstanding borrowings under the Credit Facility	165,000	$ 210,000
Letter of credit [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity	150,000
Standby letters of credit outstanding amount	46,200
Ex-Im Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity	$ 524,900
Credit facility description	The Ex-Im Credit Facility contains financial covenants regarding ViaSat's maximum total leverage ratio and minimum interest coverage ratio. In addition, the Ex-Im Credit Facility contains covenants that restrict, among other things, the Company's ability to sell assets, make investments and acquisitions, make capital expenditures, grant liens, pay dividends and make certain other restricted payments.
Borrowing availability under the Credit Facility	$ 354,900
Principal amount of outstanding borrowings under the Credit Facility	126,578	20,476
The maximum exposure fees under Ex-Im Credit Facility	$ 57,900
Interest rate on the outstanding borrowings	2.38%
Required number of installment repayments | Installment	17
Required first repayment date of borrowings under Ex-Im Credit Facility	Oct. 15, 2017
Debt maturity date	Oct. 15, 2025
The exposure fees paid under Ex-Im Credit Facility borrowings	$ 6,000
Cumulative Ex-Im Credit Facility loan discount	$ 15,800
Ex-Im Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Effective interest rate on the Ex-Im Credit Facility	4.40%
Ex-Im Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Effective interest rate on the Ex-Im Credit Facility	5.00%
Construction in progress [Member] | Property Plant and Equipment - Satellites [Member] | Ex-Im Credit Facility [Member]
Debt Instrument [Line Items]
Amount of qualified ViaSat-2 satellite costs limited to finance	$ 467,000
Percent of qualified ViaSat-2 expenses used to finance	85.00%
Initial 2020 Notes [Member]
Debt Instrument [Line Items]
Principal amounts of Senior Notes issued				$ 275,000
Additional 2020 Notes [Member]
Debt Instrument [Line Items]
Principal amounts of Senior Notes issued			$ 300,000
Original issue premium of Senior Notes			103.50%
Unamortized premium on the 2020 Notes			$ 10,500
2020 Notes [Member]
Debt Instrument [Line Items]
Interest rate on the outstanding borrowings	6.875%
Debt maturity date	Jun. 15, 2020
Principal amounts of Senior Notes issued	$ 575,000	575,000
Unamortized premium on the 2020 Notes	$ 7,025	$ 7,657
2020 Notes [Member] | Debt Instrument, Redemption, Period One [Member]
Debt Instrument [Line Items]
Redemption price percentage of Senior Notes	100.00%
Redemption description of Senior Notes	The Company may redeem the 2020 Notes prior to June 15, 2016, in whole or in part, at a redemption price equal to 100% of the principal amount thereof plus the applicable premium and any accrued and unpaid interest, if any, thereon to the redemption date. The applicable premium is calculated as the greater of: (i) 1.0% of the principal amount of such 2020 Notes and (ii) the excess, if any, of (a) the present value at such date of redemption of (1) the redemption price of such 2020 Notes on June 15, 2016 plus (2) all required interest payments due on such 2020 Notes through June 15, 2016 (excluding accrued but unpaid interest to the date of redemption), computed using a discount rate equal to the treasury rate (as defined under the indenture) plus 50 basis points, over (b) the then-outstanding principal amount of such 2020 Notes.
2020 Notes [Member] | Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Redemption price percentage of Senior Notes	103.438%
Redemption description of Senior Notes	The 2020 Notes may be redeemed, in whole or in part, at any time during the twelve months beginning on June 15, 2016 at a redemption price of 103.438%
2020 Notes [Member] | Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Redemption price percentage of Senior Notes	101.719%
Redemption description of Senior Notes	During the twelve months beginning on June 15, 2017 at a redemption price of 101.719%
2020 Notes [Member] | Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Redemption price percentage of Senior Notes	100.00%
Redemption description of Senior Notes	And at any time on or after June 15, 2018 at a redemption price of 100%, in each case plus accrued and unpaid interest, if any, thereon to the redemption date.
2020 Notes [Member] | Change of control [Member]
Debt Instrument [Line Items]
Redemption price percentage of Senior Notes	101.00%
Redemption description of Senior Notes	In the event a change of control occurs (as defined in the indenture), each holder will have the right to require the Company to repurchase all or any part of such holder's 2020 Notes at a purchase price in cash equal to 101% of the aggregate principal amount of the 2020 Notes repurchased plus accrued and unpaid interest, if any, to the date of purchase (subject to the right of holders of record on the relevant record date to receive interest due on the relevant interest payment date).