Derivatives and Risk Management Activities - Currency Exchange Rate Risk Hedging (Details) $ in Millions, $ in Billions |
3 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2025
USD ($)
$ / $
|
Dec. 31, 2025
CAD ($)
$ / $
|
Dec. 31, 2024
USD ($)
|
|
| Derivatives and Risk Management Activities | |||
| Fair value, asset | $ 4 | $ 24 | |
| Foreign currency derivatives | |||
| Derivatives and Risk Management Activities | |||
| Notional amount of derivatives | $ 4.5 | ||
| Fair value, asset | 8 | $ 0 | |
| Gains recognized | $ 8 | ||
| Average fixed exchange rate (cad per usd) | $ / $ | 1.37 | 1.37 | |
| Average exchange rate (cad per usd) | $ / $ | 1.37 | 1.37 |