Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts) (Details) - 12 months ended Dec. 31, 2025	CAD ($) MWh MMBTU T	USD ($)
Natural gas (MMBtu)
Derivative [Line Items]
Notional amount, energy measure | MMBTU	2,451,423,819
Electricity (MWh)
Derivative [Line Items]
Notional amount, energy measure	39,287,109
Foreign currency exchange ($ CAD)
Derivative [Line Items]
Notional amount, monetary measure | $	$ 67,058,920
FTR (MWh)
Derivative [Line Items]
Notional amount, energy measure	82,664
Renewable Energy Certificates (MWh)
Derivative [Line Items]
Notional amount, energy measure	11,860,903
Carbon emissions (Metric Ton)
Derivative [Line Items]
Notional amount, mass measure | T	1,113,500
Interest rate contracts ($ USD)
Derivative [Line Items]
Notional amount, monetary measure | $		$ 300,000,000