Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	$ 96,000	$ 0
2020 Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Principal amount of senior notes issued	575,000,000	575,000,000
ViaSat-1 Satellite [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Satellite performance incentives obligation and accrued interest	$ 21,800,000
Satellite Performance Incentives Obligation [Member] | ViaSat-1 Satellite [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest on in-orbit satellite performance incentive obligation	7.00%
Period of in-orbit satellite performance incentive obligation	15 years
Level 1 [Member] | 2020 Notes [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long term debt	$ 587,900,000	597,300,000
Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a recurring basis	96,000
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Ex-Im Credit Facility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long term debt	297,200,000	219,900,000
Level 2 [Member] | ViaSat-1 Satellite [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Satellite performance incentives obligation and accrued interest	$ 21,800,000	$ 22,000,000