Shares Used In Computing Diluted Net (Loss) Income Per Share - Shares Used In Computing Diluted Net Income Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Weighted average common shares outstanding used in calculating basic net (loss) income per share attributable to Viasat, Inc. common stockholders	58,638	52,976	58,237	50,542
Weighted average options to purchase common stock as determined by application of the treasury stock method		235		265
Weighted average restricted stock units to acquire common stock as determined by application of the treasury stock method		629		656
Weighted average potentially issuable shares in connection with certain terms of the ViaSat 401(k) Profit Sharing Plan and Employee Stock Purchase Plan		175		184
Weighted average shares used in computing diluted net (loss) income per share attributable to Viasat, Inc. common stockholders	58,638	54,015	58,237	51,647