Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2023
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ (93,077)	$ 76,646	$ (93,610)	$ 53,833
Effective income tax rate	11.00%	1104.00%	10.00%	(99.00%)
Increase (decrease) in gross unrecognized tax benefits	$ 4,600		$ 77,900
Valuation allowance	288,800		288,800		$ 150,000
Valuation allowance aganist R&D tax credit carryforwards			69,000
Unrecognized tax benefits, Income tax penalties and interest expense	3,500		17,700
Impact on effective tax rate	18,400		18,400
Unrecognized tax benefits	$ 207,600		207,600
Inmarsat Holdings [Member]
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits, Income tax penalties and interest expense resulting from acquisition			17,100
Unrecognized tax Benefits, Increase resulting from acquisition			$ 62,100