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		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted average common shares outstanding used in calculating basic net income (loss) per share attributable to Viasat, Inc. common stockholders	66,576	61,480	64,554	61,200
Weighted average options to purchase common stock as determined by application of the treasury stock method		174
Weighted average restricted stock units to acquire common stock as determined by application of the treasury stock method	132	973
Weighted average potentially issuable shares in connection with certain terms of the ViaSat 401(k) Profit Sharing Plan and Employee Stock Purchase Plan	298	134
Weighted average shares used in computing diluted net income (loss) per share attributable to Viasat, Inc. common stockholders	67,006	62,761	64,554	61,200