Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details) - 12 months ended Dec. 31, 2024	CAD ($) MWh MMBTU T	USD ($)
Natural gas (MMBtu)
Derivative [Line Items]
Notional amount, energy measure | MMBTU	2,061,711,943
Electricity (MWh)
Derivative [Line Items]
Notional amount, energy measure	39,109,082
Foreign currency exchange ($ CAD)
Derivative [Line Items]
Notional amount, monetary measure | $	$ 74,608,748
FTR (MWh)
Derivative [Line Items]
Notional amount, energy measure	65,874
Renewable Energy Certificates (MWh)
Derivative [Line Items]
Notional amount, energy measure	10,569,260
Carbon emissions (Metric Ton)
Derivative [Line Items]
Notional amount, mass measure | T	210,079
Interest rate contracts ($ USD)
Derivative [Line Items]
Notional amount, monetary measure | $		$ 700,000,000