Senior Notes and Other Long-Term Debt - Additional Information (Detail)		3 Months Ended	12 Months Ended
	May 17, 2017 USD ($)	Apr. 03, 2015 USD ($)	Mar. 31, 2017 USD ($) Installment	Apr. 30, 2017 USD ($)	Mar. 31, 2016 USD ($)	Oct. 31, 2012 USD ($)	Feb. 27, 2012 USD ($)
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity			$ 800,000,000
Maturity date of the Credit Facility			May 24, 2021
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.
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. As of March 31, 2017, the Revolving Credit Facility provided an $800.0 million revolving line of credit (including up to $150.0 million of letters of credit), with a maturity date of May 24, 2021 (or March 16, 2020, if more than $200.0 million of the Company’s 2020 Notes are then outstanding and certain conditions are met).
Borrowing availability under the Credit Facility			$ 761,400,000
Principal amount of outstanding borrowings under the Credit Facility			0		$ 180,000,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity			150,000,000
Standby letters of credit outstanding amount			38,600,000
Ex-Im Credit Facility [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity			$ 386,700,000
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.
Principal amount of outstanding borrowings under the Credit Facility			$ 274,600,000
Amount of qualified ViaSat-2 satellite costs limited to finance			$ 343,100,000
Percent of qualified ViaSat-2 expenses used to finance			85.00%
The maximum exposure fees under Ex-Im Credit Facility			$ 43,600,000
Interest rate on the outstanding borrowings			2.38%
Required number of installment repayments | Installment			16
Required first repayment date of borrowings under Ex-Im Credit Facility			Apr. 15, 2018
Debt maturity date			Oct. 15, 2025
The exposure fees paid under Ex-Im Credit Facility borrowings		$ 6,000,000
Exposure fees accrued as of balance sheet date expected to be financed under the Ex-Im Credit Facility			$ 29,500,000		21,000,000
Undrawn commitment under the Ex-Im Credit Facility			82,500,000
Borrowing capacity available to finance ViaSat-2 related costs once incurred			74,400,000
Cumulative Ex-Im Credit Facility loan discount			$ 36,600,000
Ex-Im Credit Facility [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Credit Facility maximum borrowing capacity	$ 362,400,000
Credit Facility reduction	24,300,000
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			4.50%
Initial 2020 Notes [Member]
Debt Instrument [Line Items]
Principal amounts of Senior Notes issued							$ 275,000,000
Additional 2020 Notes [Member]
Debt Instrument [Line Items]
Principal amounts of Senior Notes issued						$ 300,000,000
Original issue premium of Senior Notes						103.50%
Unamortized premium on the 2020 Notes						$ 10,500,000
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			$ 575,000,000		$ 575,000,000
2020 Notes [Member] | Debt Instrument, Redemption, Period One [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 12 months beginning on June 15, 2016 at a redemption price of 103.438%
2020 Notes [Member] | Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Redemption price percentage of Senior Notes			101.719%
Redemption description of Senior Notes			During the 12 months beginning on June 15, 2017 at a redemption price of 101.719%
2020 Notes [Member] | Debt Instrument, Redemption, Period Three [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).
Satellite - ViaSat-2 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Satellite performance incentives obligation	$ 21,000,000			$ 21,000,000