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) |