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
Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Weighted average common shares outstanding used in calculating basic net loss per share attributable to Viasat, Inc. common stockholders	59,208	57,842
Weighted average shares used in computing diluted net loss per share attributable to Viasat, Inc. common stockholders	59,208	57,842

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109260490&loc=d3e1448-109256

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration