Net Recognized Gains (Losses) on Debt Investments (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Realized gains from sales of available-for-sale securities	$ 8	$ 2
Realized losses from sales of available-for-sale securities	(15)	(25)
Total	463	(107)
Debt Securities
Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]
Impairments and allowance for credit losses	12	(6)
Total	$ 5	$ (29)