Income Taxes - Change in Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Balance at beginning of the year	$ 43	$ 22	$ 15
Increases related to positions taken during the current year	3	2	1
Increases recorded in current year related to positions taken during prior years	11	19	6
Settlements	(3)	0	0
Expirations due to lapse of statute	(2)	0	0
Balance at end of year	$ 52	$ 43	$ 22