Net Recognized Gains (Losses) on Debt Investments (Detail) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
|
| 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 | $ 19 |
| Realized losses from sales of available-for-sale securities | (7) | (5) |
| Total | 371 | 125 |
| 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 | (3) | 3 |
| Total | $ 9 | $ 17 |