Segment Information - Segment Revenues, Expenses and Operating Profits (Losses) (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2025	Dec. 31, 2024
Segment Reporting Information [Line Items]
Independent research and development	$ 46,929	$ 36,701	$ 123,385	$ 108,654
Communication Services [Member]
Segment Reporting Information [Line Items]
Independent research and development	26,700	21,500	67,500	66,900
Defense and Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Independent research and development	$ 20,200	$ 15,200	$ 55,900	$ 41,700