Contingencies	12 Months Ended
Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Contingencies	Note 12 — Contingencies From time to time, the Company is involved in a variety of claims, suits, investigations and proceedings arising in the ordinary course of business, including government investigations and claims, and other claims and proceedings with respect to intellectual property, breach of contract, labor and employment, tax and other matters. Such matters could result in fines; penalties, compensatory, treble or other damages; or non-monetary relief. A violation of government contract laws and regulations could also result in the termination of its government contracts or debarment from bidding on future government contracts. Although claims, suits, investigations and proceedings are inherently uncertain and their results cannot be predicted with certainty, the Company believes that the resolution of its current pending matters will not have a material adverse effect on its business, financial condition, results of operations or liquidity. In March 2016, the Company’s 52% majority-owned subsidiary TrellisWare was informed by the Civil Division of the U.S. Attorney’s Office for the Southern District of California that it was investigating TrellisWare’s eligibility for certain prior government contracts and whether TrellisWare’s conduct in connection therewith violated the False Claims Act. An estimated loss contingency is accrued when it is probable that an asset has been impaired or a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information available to determine whether such accruals should be adjusted and whether new accruals are required. During the fourth quarter of fiscal year 2017, based on further developments in that investigation and TrellisWare’s discussions with the U.S. Attorney’s Office, the Company accrued a total loss contingency of $11.8 million in SG&A expenses in its government systems segment, which consisted of $11.4 million in uncharacterized damages and $0.4 million in penalties. The impact of the loss contingency on net income attributable to Viasat, Inc. stockholders for fiscal year 2017, net of tax, was $4.0 million, with the related amount of $3.7 million recorded to net (loss) income attributable to noncontrolling interests, net of tax, while the impact on basic and diluted net income per share attributable to Viasat, Inc. common stockholders for fiscal year 2017 was $0.08 per share and $0.07 per share, respectively. As of March 31, 2017, the total loss contingency was recorded in accrued liabilities and other long term liabilities in the consolidated balance sheet in the amounts of $8.8 million and $3.0 million, respectively. In the fourth quarter of fiscal year 2018, the TrellisWare investigation was settled and the accrued amount of loss contingency was paid out in full. The Company has contracts with various U.S. government agencies. Accordingly, the Company is routinely subject to audit and review by the DCMA, the DCAA and other U.S. government agencies of its performance on government contracts, indirect rates and pricing practices, accounting and management internal control business systems, and compliance with applicable contracting and procurement laws, regulations and standards. An adverse outcome to a review or audit or other failure to comply with applicable contracting and procurement laws, regulations and standards could result in material civil and criminal penalties and administrative sanctions being imposed on the Company, which may include termination of contracts, forfeiture of profits, triggering of price reduction clauses, suspension of payments, significant customer refunds, fines and suspension, or a prohibition on doing business with U.S. government agencies. In addition, if the Company fails to obtain an “adequate” determination of its various accounting and management internal control business systems from applicable U.S. government agencies or if allegations of impropriety are made against it, the Company could suffer serious harm to its business or its reputation, including its ability to bid on new contracts or receive contract renewals and its competitive position in the bidding process. The Company’s incurred cost audits by the DCAA have not been concluded for fiscal years 2016 through 2018. As of March 31, 2018, the DCAA had completed its incurred cost audit for fiscal year 2004 and approved the Company’s incurred cost claims for fiscal years 2005 through 2015 without further audit. Although the Company has recorded contract revenues subsequent to fiscal year 2015 based upon an estimate of costs that the Company believes will be approved upon final audit or review, the Company does not know the outcome of any ongoing or future audits or reviews and adjustments, and if future adjustments exceed the Company’s estimates, its profitability would be adversely affected. As of March 31, 2018 and 2017, the Company had $1.6 million and $1.8 million, respectively, in contract-related reserves for its estimate of potential refunds to customers for potential cost adjustments on several multi-year U.S. government cost reimbursable contracts. This reserve is classified as either an element of accrued liabilities or as a reduction of unbilled accounts receivable based on the status of the related contracts.

Note 12 — Contingencies

From time to time, the Company is involved in a variety of claims, suits, investigations and proceedings arising in the ordinary course of business, including government investigations and claims, and other claims and proceedings with respect to intellectual property, breach of contract, labor and employment, tax and other matters. Such matters could result in fines; penalties, compensatory, treble or other damages; or non-monetary relief. A violation of government contract laws and regulations could also result in the termination of its government contracts or debarment from bidding on future government contracts. Although claims, suits, investigations and proceedings are inherently uncertain and their results cannot be predicted with certainty, the Company believes that the resolution of its current pending matters will not have a material adverse effect on its business, financial condition, results of operations or liquidity.

In March 2016, the Company’s 52% majority-owned subsidiary TrellisWare was informed by the Civil Division of the U.S. Attorney’s Office for the Southern District of California that it was investigating TrellisWare’s eligibility for certain prior government contracts and whether TrellisWare’s conduct in connection therewith violated the False Claims Act. An estimated loss contingency is accrued when it is probable that an asset has been impaired or a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information available to determine whether such accruals should be adjusted and whether new accruals are required. During the fourth quarter of fiscal year 2017, based on further developments in that investigation and TrellisWare’s discussions with the U.S. Attorney’s Office, the Company accrued a total loss contingency of $11.8 million in SG&A expenses in its government systems segment, which consisted of $11.4 million in uncharacterized damages and $0.4 million in penalties. The impact of the loss contingency on net income attributable to Viasat, Inc. stockholders for fiscal year 2017, net of tax, was $4.0 million, with the related amount of $3.7 million recorded to net (loss) income attributable to noncontrolling interests, net of tax, while the impact on basic and diluted net income per share attributable to Viasat, Inc. common stockholders for fiscal year 2017 was $0.08 per share and $0.07 per share, respectively. As of March 31, 2017, the total loss contingency was recorded in accrued liabilities and other long term liabilities in the consolidated balance sheet in the amounts of $8.8 million and $3.0 million, respectively. In the fourth quarter of fiscal year 2018, the TrellisWare investigation was settled and the accrued amount of loss contingency was paid out in full.

The Company has contracts with various U.S. government agencies. Accordingly, the Company is routinely subject to audit and review by the DCMA, the DCAA and other U.S. government agencies of its performance on government contracts, indirect rates and pricing practices, accounting and management internal control business systems, and compliance with applicable contracting and procurement laws, regulations and standards. An adverse outcome to a review or audit or other failure to comply with applicable contracting and procurement laws, regulations and standards could result in material civil and criminal penalties and administrative sanctions being imposed on the Company, which may include termination of contracts, forfeiture of profits, triggering of price reduction clauses, suspension of payments, significant customer refunds, fines and suspension, or a prohibition on doing business with U.S. government agencies. In addition, if the Company fails to obtain an “adequate” determination of its various accounting and management internal control business systems from applicable U.S. government agencies or if allegations of impropriety are made against it, the Company could suffer serious harm to its business or its reputation, including its ability to bid on new contracts or receive contract renewals and its competitive position in the bidding process. The Company’s incurred cost audits by the DCAA have not been concluded for fiscal years 2016 through 2018. As of March 31, 2018, the DCAA had completed its incurred cost audit for fiscal year 2004 and approved the Company’s incurred cost claims for fiscal years 2005 through 2015 without further audit. Although the Company has recorded contract revenues subsequent to fiscal year 2015 based upon an estimate of costs that the Company believes will be approved upon final audit or review, the Company does not know the outcome of any ongoing or future audits or reviews and adjustments, and if future adjustments exceed the Company’s estimates, its profitability would be adversely affected. As of March 31, 2018 and 2017, the Company had $1.6 million and $1.8 million, respectively, in contract-related reserves for its estimate of potential refunds to customers for potential cost adjustments on several multi-year U.S. government cost reimbursable contracts. This reserve is classified as either an element of accrued liabilities or as a reduction of unbilled accounts receivable based on the status of the related contracts.