Net Recognized Gains (Losses) on Debt Investments (Detail) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
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	$ 2	$ 3
Realized losses from sales of available-for-sale securities	(25)	(20)
Total	(107)	13
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	(6)	(18)
Total	$ (29)	$ (35)