Debt - Schedule of Outstanding Debt Net of Discounts and Fees, Weighted Average Contractual Interest Rates and Range of Contractual Interest Rates (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Mar. 31, 2024
Debt Instrument [Line Items]
Unsecured debt	$ 50,163	$ 41,566
Secured debt	12,384	9,351
Total debt	62,547	50,917
Commercial paper
Debt Instrument [Line Items]
Unsecured debt	$ 6,022	$ 5,293
Weighted average contractual interest rate (percentage)	4.36%	5.64%
Commercial paper \| Minimum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	2.73%	5.02%
Commercial paper \| Maximum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	4.70%	5.70%
Related party debt
Debt Instrument [Line Items]
Unsecured debt	$ 1,800	$ 0
Weighted average contractual interest rate (percentage)	4.59%	0.00%
Related party debt \| Minimum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	4.59%	0.00%
Related party debt \| Maximum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	4.60%	0.00%
Bank loans
Debt Instrument [Line Items]
Unsecured debt	$ 2,100	$ 1,804
Weighted average contractual interest rate (percentage)	4.56%	6.05%
Bank loans \| Minimum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	3.59%	5.68%
Bank loans \| Maximum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	5.27%	6.57%
Public MTN program
Debt Instrument [Line Items]
Unsecured debt	$ 37,153	$ 31,151
Weighted average contractual interest rate (percentage)	4.02%	3.58%
Public MTN program \| Minimum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	0.30%	0.30%
Public MTN program \| Maximum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	5.85%	6.06%
Other debt
Debt Instrument [Line Items]
Unsecured debt	$ 3,088	$ 3,318
Weighted average contractual interest rate (percentage)	3.53%	3.59%
Other debt \| Minimum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	1.34%	1.34%
Other debt \| Maximum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	5.73%	6.40%
Secured debt
Debt Instrument [Line Items]
Secured debt	$ 12,384	$ 9,351
Weighted average contractual interest rate (percentage)	4.77%	4.56%
Secured debt \| Minimum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	0.88%	0.27%
Secured debt \| Maximum
Debt Instrument [Line Items]
Contractual interest rate ranges (percentage)	5.87%	5.94%

Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

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- Definition

Weighted average interest rate of debt outstanding.

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No definition available.

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- Definition

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

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