Intangible Assets - Schedule of Intangible Assets (Details) - CAD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Finite-Lived and Indefinite Lived Intangible Assets [Line Items] | ||
| Cost | $ 2,301 | $ 2,294 |
| Accumulated Amortization | (791) | (746) |
| Net Book Value | 1,510 | 1,548 |
| Land, transmission and water rights | ||
| Finite-Lived and Indefinite Lived Intangible Assets [Line Items] | ||
| Cost | 1,071 | 1,064 |
| Accumulated Amortization | (182) | (171) |
| Net Book Value | 889 | 893 |
| Assets under construction | ||
| Finite-Lived and Indefinite Lived Intangible Assets [Line Items] | ||
| Cost | 58 | 110 |
| Accumulated Amortization | 0 | 0 |
| Net Book Value | 58 | 110 |
| Computer software | ||
| Finite-Lived and Indefinite Lived Intangible Assets [Line Items] | ||
| Cost | 1,040 | 985 |
| Accumulated Amortization | (528) | (497) |
| Net Book Value | 512 | 488 |
| Other | ||
| Finite-Lived and Indefinite Lived Intangible Assets [Line Items] | ||
| Cost | 132 | 135 |
| Accumulated Amortization | (81) | (78) |
| Net Book Value | $ 51 | $ 57 |