Derivatives, Hedging Activities and Interest Expense - Components of Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments Gain Loss [Line Items]
Interest expense on debt	$ 623	$ 382	$ 1,069	$ 771
Interest (income) expense on derivatives	(120)	48	(182)	114
Interest expense on debt and derivatives	503	430	887	885
Gains on debt denominated in foreign currencies	(590)	(287)	(1,181)	(277)
Losses on foreign currency swaps	743	333	1,456	358
Total interest expense	705	423	1,268	709
Interest Expense
Derivative Instruments Gain Loss [Line Items]
Losses (gains) on U.S. dollar interest rate swaps	$ 49	$ (53)	$ 106	$ (257)