Net Recognized Gains (Losses) on Debt Investments (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 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 | $ 40 | $ 22 | $ 36 |
| Realized losses from sales of available-for-sale securities | (65) | (98) | (124) |
| Total | (349) | (118) | 260 |
| 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 | 8 | 23 | (10) |
| Total | $ (17) | $ (53) | $ (98) |