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Commitments and Contingencies - Other Commitments (Narrative) (Details) | 12 Months Ended
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Dec. 31, 2024 CAD ($)
Wataynikaneyap Power |
Other Commitments [Line Items] |
Equity capital contribution | $ 137,000,000
Equity investment ownership (percent) | 39.00%
Wataynikaneyap Power | Minimum |
Other Commitments [Line Items] |
Equity capital contribution | $ 165,000,000
Wataynikaneyap Power | Maximum |
Other Commitments [Line Items] |
Equity capital contribution | 235,000,000
UNS Energy | Payment Guarantee |
Other Commitments [Line Items] |
Maximum commitment | 360,000,000
Obligation under guarantee | $ 0

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