Shares Used In Computing Diluted Net Income (Loss) Per Share - Shares Used In Computing Diluted Net Loss Per Share (Detail) - shares shares in Thousands	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Shares Used in Computing Diluted Net Income (Loss) Per Share [line Items]
Weighted average common shares outstanding used in calculating basic net income (loss) per share attributable to Viasat, Inc. common stockholders	71,543	62,511
Weighted average restricted stock units to acquire common stock as determined by application of the treasury stock method	678
Weighted average potentially issuable shares in connection with certain terms of the Viasat 401(k) Profit Sharing Plan and Employee Stock Purchase Plan	507
Weighted average shares used in computing diluted net income (loss) per share attributable to Viasat, Inc. common stockholders	72,818	62,511
Employee Stock Option [Member]
Shares Used in Computing Diluted Net Income (Loss) Per Share [line Items]
Weighted average options to purchase common stock as determined by application of the treasury stock method	6
TSR Performance Stock Options [Member]
Shares Used in Computing Diluted Net Income (Loss) Per Share [line Items]
Weighted average options to purchase common stock as determined by application of the treasury stock method	84