Shares Used In Computing Diluted Net Loss Per Share - Additional Information (Detail) - shares	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Employee Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares	1,225,233	314,113
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares	2,575,374	985,226
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	529,909	282,410
Total Shareholder Return Performance Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive shares	0	102,815