Debt and Credit Facilities - Debt and Related Weighted Average Contractual Interest Rates (Details) - USD ($) $ in Millions	Mar. 31, 2023	Mar. 31, 2022
Debt Instrument [Line Items]
Debt, Face value	$ 112,170	$ 109,449
Debt, Carrying value	$ 111,685	$ 109,152
Weighted average contractual interest rates	3.56%	1.23%
Unsecured notes and loans payable [Member]
Debt Instrument [Line Items]
Debt, Face value	$ 79,393	$ 82,542
Debt, Carrying value	$ 78,949	$ 82,288
Weighted average contractual interest rates	3.48%	1.30%
Secured notes and loans payable [Member]
Debt Instrument [Line Items]
Debt, Face value	$ 32,777	$ 26,907
Debt, Carrying value	$ 32,736	$ 26,864
Weighted average contractual interest rates	3.76%	1.01%