Shares Used In Computing Diluted Net Income (Loss) Per Share - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Employee Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares	489,293	1,276,242	201,761	1,297,427
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares	68,256	1,101,149	949,324	707,353
ViaSat 401(k) Profit Sharing Plan and Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares		289,006	230,588	249,077
Total Shareholder Return Performance Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares	1,086,737	630,102	910,494	498,062