Investment In and Advances to Non-Consolidated Affiliates and Related Party Transactions - Summary of Results of Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Schedule of Equity Method Investments [Line Items]
Income tax provision	$ 51	$ 51	$ 111	$ 105
Net income	129	157	279	313
Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Net sales	401	394	800	790
Costs and expenses related to net sales	394	381	780	762
Income tax provision	2	4	5	8
Net income	5	9	15	20
Purchases of tolling services from Alunorf	$ 77	$ 81	$ 152	$ 158