Basis of Presentation - Additional Information (Detail)			3 Months Ended		6 Months Ended
	May 30, 2023 USD ($) shares	Aug. 12, 2022 USD ($)	Sep. 30, 2023 USD ($) shares	Sep. 30, 2022 USD ($) shares	Sep. 30, 2023 USD ($) Segment shares	Sep. 30, 2022 USD ($) shares	Mar. 31, 2023 USD ($) shares	Oct. 01, 2022 USD ($)	Jun. 24, 2022
Company And Summary Of Significant Accounting Policies [Line Items]
Revenue, practical expedient, financing component					true
Remaining performance obligations			$ 3,600,000,000		$ 3,600,000,000
Number of reportable segments | Segment					3
Increase (decrease) in unbilled accounts receivable					$ 59,800,000
Increase in collections in excess of revenues and deferred revenues					139,100,000
Deferred revenues, long-term portion			920,470,000		920,470,000		$ 84,747,000
Increase (decrease) in contract with customer liability, current					4,900,000
Increase (decrease) in contract with customer liability, noncurrent					24,300,000
Collections in excess of revenues and deferred revenues, recognized revenue			23,400,000	$ 22,100,000	77,200,000	$ 97,700,000
Restricted cash relates to deposits required by certain counterparties as collateral pursuant to outstanding letters of credit			7,184,000		7,184,000		30,532,000
Capitalized interest expense			70,200,000	38,500,000	$ 126,900,000	72,100,000
Proportion of insured amount to asset net book value					On July 12, 2023, the Company reported a reflector deployment issue that materially impacted the performance of the ViaSat-3 F1 satellite. The Company and the reflector provider conducted a rigorous review of the development and deployment of the affected reflector to determine its impact and potential remedial measures. In connection with the root cause analysis, the Company determined that while the satellite payload is functional, the Company will recover less than 10% of the planned throughput on the ViaSat-3 F1 satellite.
Operating lease, existence of option to terminate					true
Operating lease, option to terminate, description					some of which include renewal options, and some of which include options to terminate the leases within one year.
Total capitalized costs related to patents			3,800,000		$ 3,800,000		3,700,000
Total capitalized costs related to orbital slots and other licenses			80,900,000		80,900,000		77,000,000
Accumulated amortization of patents, orbital slots and other licenses			7,600,000		7,600,000		6,800,000
Debt issuance costs capitalized					50,100,000	0
Capitalized costs, net, related to software developed for resale			224,712,000		224,712,000		222,155,000
Capitalized cost related to software development for resale			15,000,000	15,900,000	31,000,000	24,600,000
Amortization expense of capitalized software development costs			14,100,000	13,700,000	28,500,000	22,900,000
Self-insurance liability			7,300,000		7,300,000		$ 7,900,000
Repurchase and immediate retirement of treasury shares pursuant to vesting of certain RSU agreements | value			353,000	327,000	2,565,000	832,000
Stock-based compensation expense					43,470,000	43,806,000
Payments for repurchase of common stock						30,000,000
Common stock, shares authorized | shares	200,000,000						100,000,000
Insurance claim receivables			770,000,000		770,000,000
Selling, general and administrative expenses			1,148,989,000	177,191,000	1,368,570,000	348,816,000
Interest Rate Cap [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Gain (loss) in other comprehensive income arising from changes in the fair value of derivative contracts (designated as cash-flow hedging instruments)			7,900,000		20,600,000
Interest rate cap contracts			54,100,000		54,100,000
Derivative contracts gain (loss) reclassified from other comprehensive income to interest expense (based on the nature of the underlying transaction)			14,300,000		$ 18,700,000
Interest rate cap contracts, description					The interest rate cap contracts provided protection of Compound SOFR up to 2% and covered 99% of the total nominal amount of the Inmarsat Term Loan Facility. At the time of the acquisition, the Company continued to account for the interest rate cap contracts as cash-flow hedges
Tax on gain (loss) arising from changes in the fair value of the interest rate cap contracts (designated as cash-flow hedging instruments)			2,000,000		$ 5,200,000
Tax related to the reclassification of other comprehensive income to interest expense (based on the nature of the underlying transaction)			(3,600,000)		(4,700,000)
Interest Rate Cap [Member] | Other Current Assets [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Interest rate cap contracts			54,100,000		54,100,000
Interest Rate Cap [Member] | Other Noncurrent Assets [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Interest rate cap contracts			18,100,000		18,100,000
Letter of Credit [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Restricted cash relates to deposits required by certain counterparties as collateral pursuant to outstanding letters of credit			7,200,000		7,200,000		$ 30,500,000
Continuing Operations [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Stock-based compensation expense			21,700,000	$ 21,900,000	$ 43,500,000	$ 42,100,000
Link-16 Tactical Data Link Business [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Disposal consideration								$ 1,960,000,000
Inmarsat Term Loan Facility [Member] | Interest Rate Cap [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Interest rate cap	2.00%
Interest rate cap contracts percentage of protection of nominal amount	99.00%
Accounting Standards Update 2021-08 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements					In October 2021, the Financial Accounting Standards Board (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 Company adopted the new guidance prospectively in the first quarter of fiscal year 2024 and applied its provisions to the Inmarsat Acquisition (see Note 4 – Acquisition).
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): Fair Value Hedging—Portfolio Layer Method. ASU 2022-01 clarifies the accounting and promotes consistency in reporting for hedges where the portfolio layer method is applied. The Company adopted the new guidance in the first quarter of fiscal year 2024 and the guidance did not have a material impact 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					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 Company adopted the new guidance prospectively in the first quarter of fiscal year 2024 and the guidance did not have a material impact on its consolidated financial statements and disclosures.
Accounting Standards Update 2022-03 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements					In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (ASC 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions. ASU 2022-03 clarifies that a contractual restriction on the sale of an equity security is not considered in measuring the security's fair value. The standard also requires certain disclosures for equity securities that are subject to contractual restrictions. The new standard will become effective for the Company beginning in fiscal year 2025. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.
Accounting Standards Update 2022-04 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements					In September 2022, the FASB issued ASU 2022-04, Liabilities – Supplier Finance Programs (Subtopic 405-50): Disclosure of Supplier Finance Program Obligations. ASU 2022-04 enhances the transparency of supplier finance programs. In each annual reporting period, the buyer in a supplier finance program is required to disclose information about the key terms of the program, the outstanding confirmed amounts, a rollforward of such amounts, and a description of where those obligations are presented in the balance sheet. In each interim reporting period, the buyer should disclose the outstanding confirmed amounts as of the end of the interim period. The Company adopted the new guidance in the first quarter of fiscal year 2024 (including early adoption of the amendment on the rollforward information) and the guidance did not have a material impact on its consolidated financial statements and disclosures.
Accounting Standards Update 2023-01 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements					In March 2023, the FASB issued ASU 2023-01, Leases (Topic 842) – Common Control Agreements. The amendments in this update that apply to public business entities clarify the accounting for leasehold improvements associated with common control leases. The new standard will become effective for the Company beginning in fiscal year 2025. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.
Accounting Standards Update 2023-03 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements					In July 2023, the FASB issued ASU 2023-03, Presentation of Financial Statements (Topic 205), Income Statement – Reporting Comprehensive Income (Topic 220), Distinguishing Liabilities from Equity (Topic 480), Equity (Topic 505), and Compensation – Stock Compensation (Topic 718). This ASU amends various paragraphs in the accounting codification pursuant to the issuance of Commission Staff Accounting Bulletin (SAB) number 120. The ASU provides clarifying guidance related to employee and non-employee share-based payment accounting, including guidance related to spring-loaded awards. ASU 2023-03 is effective upon issuance. The adoption of this guidance upon issuance did not have a material impact on the Company’s consolidated financial statements and disclosures.
CPE Leased Equipment [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, cost			678,679,000		$ 678,679,000		395,427,000
Accumulated depreciation and amortization			227,300,000		$ 227,300,000		213,600,000
ViaSat-3 F1 satellite [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Maximum expected recovery % of the planned throughput					10.00%
Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Reduction to carrying value including capitalized interest			1,600,000,000		$ 1,600,000,000
Insurance claim receivables			770,000,000		$ 770,000,000
Satellites [Member] | Selling General and Administrative Expenses [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Satellite impairment loss, net, including liabilities associated with the termination of certain subcontractor agreements			$ 900,000,000
Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			2 years		2 years
Financing lease, remaining lease term			1 year		1 year
Operating lease, remaining lease term			1 year		1 year
Estimated useful life, years			2 years		2 years
Minimum [Member] | Software Development Member
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			3 years		3 years
Minimum [Member] | CPE Leased Equipment [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			4 years		4 years
Minimum [Member] | Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years		7 years
Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			38 years		38 years
Financing lease, remaining lease term			3 years		3 years
Operating lease, remaining lease term			14 years		14 years
Estimated useful life, years			20 years		20 years
Maximum [Member] | Software Development Costs [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life, years			5 years		5 years
Maximum [Member] | Software Development Member
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years		7 years
Maximum [Member] | CPE Leased Equipment [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			7 years		7 years
Maximum [Member] | Satellites [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)			17 years		17 years
Inmarsat Holdings [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Payments to acquire business	$ 550,700,000
Shares issued in connection with acquisition of business, net of issuance costs , shares | shares	46,360,000
Increase (decrease) in unbilled accounts receivable					$ 16,300,000
Increase in collections in excess of revenues and deferred revenues					144,000,000
Deferred revenues, long-term portion					$ 860,000,000
Funded Research and Development from Customer Contracts [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			12.00%	14.00%	13.00%	15.00%
TrellisWare [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Payments for repurchase of common stock		$ 30,000,000
Minority interest ownership percentage by parent									60.00%
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			92.00%	89.00%	90.00%	87.00%
U.S. Government as an Individual Customer [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			16.00%	18.00%	16.00%	17.00%
Other Customers [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			84.00%	82.00%	84.00%	83.00%
Unfavorable Regulatory Action [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Accrued reserves			$ 15,600,000		$ 15,600,000		12,900,000
Indemnification Guarantee [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Accrued reserves			$ 0		$ 0		$ 0
Common Stock [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Shares issued in connection with acquisition of business, net of issuance costs , shares | shares					46,363,636
Common stock issued based on the vesting terms of certain restricted stock unit agreements | shares			57,027	41,930	194,496	88,401
Common Stock Held in Treasury [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Shares of common stock outstanding | shares			0		0		0
Repurchase and immediate retirement of treasury shares pursuant to vesting of certain RSU agreements, shares | shares			12,551	8,532	61,401	21,697
Repurchase and immediate retirement of treasury shares pursuant to vesting of certain RSU agreements | value					$ 2,600,000