Net Recognized Gains (Losses) on Equity Investments (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items] | ||||
| Net realized gains (losses) on investments sold | $ (8) | $ (31) | $ 57 | $ 14 |
| Net unrealized gains on investments still held | 25 | 286 | 437 | 163 |
| Total | (860) | 69 | (397) | (38) |
| Equity Securities | ||||
| Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items] | ||||
| Impairments of investments | (853) | (179) | (872) | (179) |
| Total | $ (836) | $ 76 | $ (378) | $ (2) |