Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2023	Mar. 31, 2024		Mar. 31, 2023	Mar. 31, 2022
Valuation and Qualifying Accounts Disclosure [Line Items]
Charged to costs and expenses	$ 69,000
Deferred Tax Asset Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance		$ 150,047		$ 78,071	$ 47,076
Charged to costs and expenses		139,687		71,976	5,119
Charged to goodwill		63,908	[1]		25,876	[2]
Ending Balance		$ 353,642		$ 150,047	$ 78,071

[1] Related to the acquisition of Inmarsat

[2] Related to the acquisitions of RigNet and EBI