Derivatives, Hedging Activities and Interest Expense - Components of Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments Gain Loss [Line Items]
Interest expense on debt	$ 845	$ 362	$ 1,914	$ 1,134
Interest (income) expense on derivatives	(186)	23	(368)	137
Interest expense on debt and derivatives	659	385	1,546	1,271
Losses (gains) on debt denominated in foreign currencies	532	(60)	(649)	(338)
(Gains) losses on foreign currency swaps	(509)	151	947	509
Total interest expense	765	346	2,033	1,055
Interest Expense
Derivative Instruments Gain Loss [Line Items]
Losses (gains) on U.S. dollar interest rate swaps	$ 83	$ (130)	$ 189	$ (387)