Segment Information - Other Acquired Intangible Assets, Net, Goodwill Included in Segment Assets and Depreciation and Amortization of Acquired Intangible Assets by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2023	Mar. 31, 2024
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	$ 2,338,088		$ 2,338,088		$ 2,544,467
Goodwill	1,620,267		1,620,267		1,621,763
Depreciation and amortization of intangible assets	337,755	$ 336,626	1,023,625	$ 844,970
Operating Segments [Member] | Communication Services [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net	2,338,088		2,338,088		2,544,315
Goodwill	1,580,480		1,580,480		1,581,937
Depreciation and amortization of intangible assets	254,962	231,274	776,134	604,738
Operating Segments [Member] | Defense and Advanced Technologies [Member]
Segment Reporting Information [Line Items]
Other acquired intangible assets, net					152
Goodwill	39,787		39,787		$ 39,826
Depreciation and amortization of intangible assets	16,946	13,633	49,405	39,328
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization of intangible assets	$ 65,847	$ 91,719	$ 198,086	$ 200,904