Income Taxes - Components of Income before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Income Tax Disclosure [Abstract]
United States	$ 548,018	$ 571,649	$ 641,370
Foreign	11,770	17,816	25,383
Income before income taxes	$ 559,788	$ 589,465	$ 666,753

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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