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Debt (Senior Notes) (Details) € in Millions	1 Months Ended	12 Months Ended
Debt (Senior Notes) (Details) € in Millions	Jan. 31, 2025 USD ($)	Mar. 31, 2025 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2025 EUR (€)	Aug. 31, 2021 USD ($)
Debt Instrument [Line Items]
Long-term debt, principal		$ 5,832,000,000	$ 4,914,000,000
Loss on extinguishment of debt, net		7,000,000	5,000,000	$ 0
ABL Revolver
Debt Instrument [Line Items]
Long-term debt, principal	$ 738,000,000
Extinguishment of debt	738,000,000
Senior Notes
Debt Instrument [Line Items]
Principal amount		$ 1,600,000,000
Interest rates		4.75%			4.75%
Senior Notes \| 3.250% Senior Notes, due November 2026
Debt Instrument [Line Items]
Principal amount						$ 750,000,000
Long-term debt, principal		$ 750,000,000	750,000,000
Interest rates						3.25%
Debt issuance costs, net						$ 11,000,000
Senior Notes \| 3.375% Senior Notes, due April 2029
Debt Instrument [Line Items]
Principal amount \| €					€ 500
Long-term debt, principal		$ 540,000,000	540,000,000
Interest rates		3.375%			3.375%
Debt issuance costs, gross			13,000,000
Senior Notes \| 4.750% Senior Notes, due January 2030
Debt Instrument [Line Items]
Long-term debt, principal		$ 1,600,000,000	1,600,000,000
Interest rates		4.75%			4.75%
Senior Notes \| 3.875% Senior Notes, due August 2031
Debt Instrument [Line Items]
Long-term debt, principal		$ 750,000,000	750,000,000
Interest rates		3.875%			3.875%
Senior Notes \| 6.875% Senior Notes, due January 2030
Debt Instrument [Line Items]
Principal amount	$ 750,000,000
Long-term debt, principal		$ 750,000,000	$ 0
Interest rates	6.875%	6.875%			6.875%
Debt issuance costs, gross	$ 12,000,000
Senior Notes \| 5.875% Senior Notes due September 2026
Debt Instrument [Line Items]
Interest rates						5.875%
Senior Notes \| Senior Notes Due 2030
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Interest rate		4.75%			4.75%
3.875% Senior Notes, due August 2031
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Long-term debt, principal		$ 750,000,000
Debt issuance costs, gross		11,000,000
3.250% Senior Notes, due November 2026
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Debt issuance costs, gross		$ 11,000,000