Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2023
Operating Loss Carryforwards [Line Items]
(Provision for) benefit from income taxes from continuing operations	$ 34,496	$ (5,212)	$ 128,106	$ (59,045)
Effective income tax rate	22.00%	(13.00%)	12.00%	(63.00%)
Increase (decrease) in gross unrecognized tax benefits	$ (28,300)		$ 49,600
Valuation allowance	285,100		285,100		$ 150,000
Valuation allowance aganist R&D tax credit carryforwards			69,000
Increase (decrease) in unrecognized tax benefits income tax penalties and interest expense	(7,600)		10,100
Impact on effective tax rate	14,500		14,500
Unrecognized tax benefits	$ 179,300		179,300
Inmarsat Holdings [Member]
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits, Income tax penalties and interest expense resulting from acquisition			14,900
Unrecognized tax Benefits, Increase resulting from acquisition			$ 51,600