Acquisitions - (Additional Information) (Detail) shares in Thousands, € in Millions			1 Months Ended	12 Months Ended
	Nov. 08, 2021 USD ($) shares	Apr. 30, 2021 USD ($) shares	Mar. 31, 2017 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Mar. 04, 2022 USD ($)	Apr. 30, 2021 EUR (€)
Business Acquisition [Line Items]
Net cash outlay after acquiree's cash on hand				$ 139,533,000
Shares issued in connection with acquisition of business				207,169,000
Total revenues				$ 2,787,635,000	$ 2,256,107,000	$ 2,309,238,000
Term Loan Facility [Member]
Business Acquisition [Line Items]
Credit Facility maximum borrowing capacity							$ 700,000,000.0
EBI [Member]
Business Acquisition [Line Items]
Equity method investment ownership percentage			49.00%
EBI Step Acquisition [Member]
Business Acquisition [Line Items]
Percentage of additional interest in subsidiary acquired		51.00%						51.00%
Ownership percentage after completing the acquisition		100.00%						100.00%
The consideration transferred		$ 327,400,000	$ 160,400,000
Payments to acquire business		167,000,000.0
Euro Infrastructure Co.'s cash on hand		121,700,000
Net cash outlay after acquiree's cash on hand		$ 51,000,000.0
Contingent consideration arrangements		the Company may pay or receive up to €20.0 million, or approximately $22.3 million, in cash		up to plus or minus €20.0 million
EBI Step Acquisition [Member] | Maximum [Member]
Business Acquisition [Line Items]
Amount of estimated purchase price consideration to be settled among the parties over the next 24 months from the closing date		$ 22,300,000						€ 20.0
RigNet, Inc [Member]
Business Acquisition [Line Items]
The consideration transferred		317,900,000
Shares issued in connection with acquisition of business		$ 207,200,000
Shares issued in connection with acquisition of business, shares | shares		4,000
Pay down of outstanding borrowings of acquiree		$ 107,300,000
Remaining amount payable				$ 0
Total revenues				180,200,000
Net losses				31,200,000
RigNet, Inc [Member] | Selling General and Administrative Expenses [Member]
Business Acquisition [Line Items]
Merger-related transaction costs				$ 7,200,000
RigNet, Inc [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration liability		$ 13,800,000
Inmarsat [Member]
Business Acquisition [Line Items]
Consideration payable under the Share Purchase Agreement in cash, subject to adjustments	$ 850,000,000.0
Consideration payable under the Share Purchase Agreement in common stock, subject to adjustments | shares	46,360
Reduction of cash purchase price consideration to be paid upon completion of acquisition	$ 299,300,000
Termination fee payable upon termination of the Share Purchase Agreement under certain circumstances	200,000,000.0
Reimbursement of certain out-of-pocket expenses of certain sellers upon termination of the Share Purchase Agreement under certain circumstances	40,000,000.0
Financing commitments in connection with acquisition	1,600,000,000
Commitment obtained to backstop certain amendments required under current credit facilities	3,200,000,000
Expected additional new financing commitments in connection with acquisition	1,300,000,000
Inmarsat Legal Entity [Member]
Business Acquisition [Line Items]
Principal amount of senior secured debt	2,100,000,000
Outstanding indebtedness borrowings under the Credit Facility	2,400,000,000
Financing commitments	2,400,000,000
Distributed earnings	$ 299,300,000