Basis of Presentation - Additional Information (Detail)			3 Months Ended		6 Months Ended
	Aug. 12, 2022 USD ($)	Jul. 08, 2022 USD ($)	Sep. 30, 2022 USD ($) shares	Sep. 30, 2021 USD ($) shares	Sep. 30, 2022 USD ($) Segment shares	Sep. 30, 2021 USD ($) shares	Oct. 01, 2022 USD ($)	Jun. 24, 2022	Mar. 31, 2022 USD ($) shares	Apr. 30, 2021
Company And Summary Of Significant Accounting Policies [Line Items]
Legal settlement received		$ 62,200,000
Revenues			$ 55,800,000
Interest income					$ 6,400,000
Revenue, practical expedient, financing component					true
Remaining performance obligations			2,400,000,000		$ 2,400,000,000
Revenue attributable to discontinued operations			599,700,000		$ 599,700,000
Number of reportable segments | Segment					3
Increase (decrease) in unbilled accounts receivable					$ (2,400,000)
Decrease in collections in excess of revenues and deferred revenues					(2,000,000.0)
Collections in excess of revenues and deferred revenues, recognized revenue			22,100,000	$ 34,300,000	97,700,000	$ 109,200,000
Capitalized interest expense			38,500,000	24,800,000	$ 72,100,000	48,400,000
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			3,600,000		$ 3,600,000				$ 3,500,000
Total capitalized costs related to orbital slots and other licenses			72,600,000		72,600,000				64,100,000
Accumulated amortization of patents, orbital slots and other licenses			6,000,000.0		6,000,000.0				5,400,000
Debt issuance costs capitalized					0	0
Capitalized costs, net, related to software developed for resale			218,865,000		218,865,000				217,159,000
Capitalized cost related to software development for resale			15,900,000	11,000,000.0	24,600,000	20,900,000
Amortization expense of capitalized software development costs			13,700,000	14,100,000	22,900,000	28,200,000
Self-insurance liability			6,500,000		6,500,000				5,800,000
Repurchase and immediate retirement of treasury shares pursuant to vesting of certain RSU agreements | value			327,000	1,284,000	832,000	1,742,000
Stock-based compensation expense					43,806,000	43,241,000
Payments for repurchase of common stock					30,000,000
Continuing Operations [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Stock-based compensation expense			21,900,000	$ 20,600,000	42,100,000	$ 42,300,000
Link-16 Tactical Data Link Business [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Disposal consideration							$ 1,960,000,000
Term Loan Facility [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Principal amount of debt			698,250,000		698,250,000				700,000,000
Principal amount of debt			700,000,000.0		$ 700,000,000.0				700,000,000.0
Accounting Standards Update 2020-06 [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Description of new accounting pronouncements					In August 2020, the Financial Accounting Standards Board (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 Company adopted the new guidance in the first quarter of fiscal year 2023 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 is effective for annual periods beginning after December 15, 2021. The Company will adopt this guidance effective fiscal year-end 2023. The Company is currently evaluating the impact of this standard on its annual 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.
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 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 2022-03 [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 new standard will become effective for the Company beginning in fiscal year 2024, except for the amendment on rollfoward information, which will become effective in fiscal year 2025. The Company is currently evaluating the impact of this standard on its consolidated financial statements and disclosures.
CPE Leased Equipment [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, cost			380,240,000		$ 380,240,000				395,539,000
Accumulated depreciation and amortization			$ 208,600,000		$ 208,600,000				210,600,000
Minimum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (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
Minimum [Member] | Software Development Member
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (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
Maximum [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (years)					38 years
Financing lease, remaining lease term			4 years		4 years
Operating lease, remaining lease term			10 years		10 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
Maximum [Member] | Software Development Member
Company And Summary Of Significant Accounting Policies [Line Items]
Property, equipment and satellites, estimated useful life (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)					5 years
Euro Broadband Infrastructure Sarl Step Acquisition [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of additional interest purchased in subsidiary acquired				51.00%		51.00%				51.00%
Funded Research and Development from Customer Contracts [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			14.00%	18.00%	16.00%	18.00%
TrellisWare [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Minority interest ownership percentage by parent								60.00%
Payments for repurchase of common stock	$ 30,000,000.0
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			89.00%	92.00%	86.00%	90.00%
U.S. Government as an Individual Customer [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			17.00%	18.00%	16.00%	20.00%
Other Customers [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue			83.00%	82.00%	84.00%	80.00%
Unfavorable Regulatory Action [Member]
Company And Summary Of Significant Accounting Policies [Line Items]
Accrued reserves			$ 12,100,000		$ 12,100,000				12,100,000
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]
Common stock issued based on the vesting terms of certain restricted stock unit agreements | shares			41,930	99,947	88,401	129,007
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			8,532	24,617	21,697	33,338
Repurchase and immediate retirement of treasury shares pursuant to vesting of certain RSU agreements | value				$ 1,300,000	$ 1,700,000