The Company and a Summary of Its Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Mar. 31, 2022 USD ($) Segment shares	Mar. 31, 2021 USD ($) shares	Mar. 31, 2020 USD ($) shares	Apr. 30, 2021
Company And Summary Of Significant Accounting Policies [Line Items]
Capitalized interest expense			$ 102,100,000	$ 81,000,000.0	$ 54,100,000
Proceeds from insurance claims on ViaSat-2 satellite					2,277,000
Total capitalized costs related to patents			3,500,000	3,500,000
Total capitalized costs related to orbital slots and other licenses			64,100,000	53,800,000
Accumulated amortization of patents, orbital slots and other licenses			5,400,000	4,400,000
Patents, orbital slots and other licenses amortization expense			1,100,000
Debt issuance costs capitalized			7,800,000	5,100,000	0
Capitalized costs, net, related to software developed for resale			221,647,000	237,100,000
Capitalized cost related to software development for resale			42,600,000	54,000,000.0
Amortization expense of capitalized software development costs			58,100,000	59,600,000	53,000,000.0
Goodwill and other intangible assets impairment			$ 0	0	0
Maximum warranty periods provided on limited warranty			5 years
Self-insurance liability			$ 6,500,000	$ 6,900,000
Shares of common stock outstanding | shares			74,428,816	68,529,133
Repurchase and immediate retirement of treasury shares pursuant to vesting of certain RSU agreements			$ 22,969,000	$ 13,676,000	28,802,000
Other comprehensive income (loss) related to effects of foreign currency translation adjustments before tax			(37,300,000)	20,400,000	(12,800,000)
Foreign currency translation adjustments, net of tax			$ (31,424,000)	15,851,000	(11,621,000)
Revenue, practical expedient, financing component			true
Remaining performance obligations			$ 2,000,000,000.0
Number of reportable segments | Segment			3
Increase (decrease) in unbilled accounts receivable			$ 32,300,000
Increase in collections in excess of revenues and deferred revenues			67,700,000
Collections in excess of revenues and deferred revenues, recognized revenue		$ 193,200,000		98,600,000
Capitalized contract cost amortization and reduction of carrying value associated with contract termination			$ 56,900,000	$ 50,500,000	46,400,000
Revenue, practical expedient, incremental cost of obtaining contract [true false]			true	true
Advertising costs			$ 23,100,000	$ 12,000,000.0	25,800,000
Benefit from (provision for) income taxes			(14,237,000)	9,441,000	$ (7,915,000)
RigNet, Inc [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Contract with Customer, Asset, Increase (Decrease) for Contract Acquired in Business Combination			17.5
EBI Step Acquisition [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of additional interest purchased in subsidiary acquired						51.00%
Prepaid Expenses and Other Current Assets [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Deferred customer contract costs			24,600,000	26,800,000
Other Assets [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Deferred customer contract costs			60,100,000	57,800,000
Deferred Customer Contract Acquisition Costs [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Deferred customer contract costs			49,700,000	60,400,000
Deferred Customer Contract Fulfillment Costs [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Deferred customer contract costs			$ 35,000,000.0	$ 24,200,000
Accounting Standards Update 2019-12 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2019-12, Income Taxes (ASC 740): Simplifying the Accounting for Income Taxes, which is intended to simplify various areas related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in ASC 740 and also clarifies and amends existing guidance to improve consistent application. The Company adopted the new guidance in the first quarter of fiscal year 2022 on a prospective basis and as a result upon purchase of the remaining 51% interest in EBI from Eutelsat (see Note 16 — Acquisitions for more information), and assertion to permanently reinvest future earnings, the deferred tax liability recorded for EBI’s outside basis difference of $8.1 million was reversed and recorded in the first quarter of fiscal year 2022 as an income tax benefit in the consolidated statements of operations and comprehensive income (loss).
Benefit from (provision for) income taxes	$ 8,100,000
Accounting Standards Update 2020-01 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			In January 2020, the FASB issued ASU 2020-01, Investments – Equity Securities (ASC 321), Investments – Equity Method and Joint Ventures (ASC 323) and Derivatives and Hedging (ASC 815). ASU 2020-01 clarifies the interaction of the accounting for equity securities under ASC 321 and investments accounted for under the equity method of accounting under ASC 323, and the accounting for certain forward contracts and purchased options accounted for under ASC 815. The Company adopted the new guidance in the first quarter of fiscal year 2022 on a prospective basis and the guidance did not have a material impact on the Company's consolidated financial statements and disclosures.
Accounting Standards Update 2020-06 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			In August 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (ASC 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40). ASU 2020-06 simplifies the accounting for convertible instruments by removing the beneficial conversion and cash conversion accounting models for convertible instruments and removes certain settlement conditions that are required for contracts to qualify for equity classification. This new standard also simplifies the diluted earnings per share calculations by requiring that an entity use the if-converted method for convertible instruments and requires that the effect of potential share settlement be included in diluted earnings per share calculations when an instrument may be settled in cash or shares. The new standard requires entities to provide expanded disclosures about the terms and features of convertible instruments, how the instruments have been reported in the entity’s financial statements, and information about events, conditions, and circumstances that can affect how to assess the amount or timing of an entity’s future cash flows related to those instruments. The new standard will become effective for the Company beginning in fiscal year 2023, with early adoption permitted. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.
Accounting Standards Update 2020-08 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			In October 2020, the FASB issued ASU 2020-08, Codification Improvements to Subtopic 310-20, Receivables – Nonrefundable Fees and Other Costs. ASU 2020-08 clarifies that a company should reevaluate whether a callable debt security is within the scope of ASC paragraph 310-20-35-33 for each reporting period. The Company adopted the new guidance in the first quarter of fiscal year 2022 on a prospective basis and the guidance did not have a material impact on the Company's consolidated financial statements and disclosures.
Accounting Standards Update 2021-08 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			In October 2021, the FASB issued ASU 2021-08, Business Combinations (ASC 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. ASU 2021-08 requires contract assets and contract liabilities acquired in a business combination to be recognized in accordance with ASC 606 as if the acquirer had originated the contracts. The new standard will become effective for the Company beginning in fiscal year 2024, with early adoption permitted. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.
Accounting Standards Update 2021-10 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			In November 2021, the FASB issued ASU 2021-10, Government Assistance (ASC 832): Disclosures by Business Entities about Government Assistance. ASU 2021-10 requires annual disclosures when an entity accounts for a transaction with a government by applying a grant or contribution accounting model by analogy to other accounting guidance. The new standard will become effective for the Company in fiscal year 2023. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.
Accounting Standards Update 2022-01 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging (ASC 815): Targeted Improvements to Accounting for Hedging Activities. ASU 2022-01 made targeted improvements to the optional hedge accounting model with the objective of improving hedge accounting to better portray the economic results of an entity’s risk management activities in its financial statements. The new standard will become effective for the Company beginning in fiscal year 2024. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.In March 2022, the FASB issued ASU 2022-02, Financial Instruments – Credit Losses (ASC 326): Troubled Debt Restructurings and Vintage Disclosures. ASU 2022-02 eliminates the accounting guidance for troubled debt restructurings by creditors in Subtopic 310-40, Receivables – Troubled Debt Restructurings by Creditors, while enhancing certain disclosure requirements for loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. Furthermore, it requires that an entity disclose current-period gross write-offs by year of origination for financing receivables and net investments in leases within the scope of Subtopic 326-20, Financial Instruments – Credit Losses – Measured at Amortized Cost. The new standard will become effective for the Company beginning in fiscal year 2024. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.
Accounting Standards Update 2022-02 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements			I
Funded Research and Development from Customer Contracts [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			23.00%	23.00%	24.00%
Operating Segments [Member] | Commercial Networks and Government Systems [Member] | Fixed-price Contract [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			90.00%	89.00%	88.00%
U.S. Government as an Individual Customer [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			25.00%	30.00%	30.00%
Other Customers [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			75.00%	70.00%	70.00%
Common Stock Held in Treasury [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Shares of common stock outstanding | shares			0	0
Purchase of treasury shares pursuant to vesting of certain RSU agreements | shares			445,257	376,884	385,604
Repurchase and immediate retirement of treasury shares pursuant to vesting of certain RSU agreements			$ 23,000,000.0	$ 13,700,000	$ 28,800,000
Common Stock [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Common stock issued based on the vesting terms of certain restricted stock unit agreements | shares			1,274,311	1,064,680	1,075,526
Indemnification Agreement [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Accrued reserves			$ 0	$ 0
Unfavorable Regulatory Action [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Accrued reserves			$ 12,100,000	10,300,000
Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			2 years
Estimated useful life, years			2 years
Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			38 years
Estimated useful life, years			20 years
Maximum [Member] | Software Development Costs [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life, years			5 years
Internally Developed Software [Member] | Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			3 years
Internally Developed Software [Member] | Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years
CPE Leased Equipment [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites			$ 395,539,000	409,942,000
Accumulated depreciation and amortization				$ 193,700,000
CPE Leased Equipment [Member] | Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			4 years
CPE Leased Equipment [Member] | Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			5 years
Satellites [Member] | Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years
Satellites [Member] | Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			17 years
Government Contracts Concentration Risk [Member] | Sales Revenue, Net [Member] | U.S. Government as an Individual Customer [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage			25.00%	30.00%	30.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Five Largest Contracts [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage			20.00%	16.00%	18.00%
Credit Concentration Risk [Member] | Accounts Receivable [Member] | U.S. Government as an Individual Customer [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage			18.00%	27.00%