PROPERTY, PLANT AND EQUIPMENT - Narrative (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 4,600	$ 4,000	$ 3,800
Chapman Ranch Wind Farm
Property, Plant and Equipment [Line Items]
Impairment loss		$ 251
Magic Valley Wind Farm
Property, Plant and Equipment [Line Items]
Impairment loss			227
Bakken Pipeline System
Property, Plant and Equipment [Line Items]
Impairment loss			$ 183