Supplemental Information (Contract Liabilities) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |
|---|---|---|---|
Sep. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Contract with Customer, Liability [Roll Forward] | |||
| Contract liabilities, beginning balance | $ 60 | $ 147 | $ 62 |
| Revenues recognized that were included in the contract liability balances at the beginning of the period | (4) | (2) | |
| Increases due to cash received and due, excluding amounts recognized as revenues during the period | 15 | 0 | |
| Contract liabilities, ending balance | $ 158 | $ 60 | |
| Advance payment representing fixed portion of total transaction price | $ 70 | ||