Results of Operations from Oil and Gas Producing Activities (Parenthetical) (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Jun. 30, 2021 |
Jun. 30, 2020 |
Jun. 30, 2019 |
|
| Results of operations for oil and gas producing activities by geographic area [line items] | |||
| Sales to affiliated companies | $ 51 | $ 62 | $ 75 |
| Valuation provision | 101 | 12 | 21 |
| Results of oil and gas producing activities | 251 | 298 | 1,671 |
| Discontinued operations [member] | Onshore US [Member] | |||
| Results of operations for oil and gas producing activities by geographic area [line items] | |||
| Results of oil and gas producing activities | $ 0 | $ 0 | $ 431 |