Net Recognized Gains (Losses) on Debt Investments (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| 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 | $ 19 | $ 9 | $ 35 | $ 17 |
| Realized losses from sales of available-for-sale securities | (9) | (19) | (19) | (34) |
| Total | 339 | (860) | (233) | (397) |
| 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 | (21) | (14) | (17) | (2) |
| Total | $ (11) | $ (24) | $ (1) | $ (19) |