Net Recognized Gains (Losses) on Equity 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] | ||||
| Net realized gains (losses) on investments sold | $ 3 | $ (8) | $ 74 | $ 57 |
| Net unrealized gains (losses) on investments still held | 385 | 25 | (250) | 437 |
| Total | 339 | (860) | (233) | (397) |
| 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 | (38) | (853) | (56) | (872) |
| Total | $ 350 | $ (836) | $ (232) | $ (378) |