INCOME TAXES - Schedule of Major Components of Deferred Income Tax Assets and Liabilities (Details) - CAD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred income tax liabilities
Property, plant and equipment	$ (11,368)	$ (9,202)
Investments	(9,043)	(7,765)
Regulatory assets	(1,940)	(1,338)
Other	(251)	(52)
Total deferred income tax liabilities	(22,602)	(18,357)
Deferred income tax assets
Financial instruments	740	271
Loss carryforwards	1,272	1,745
Other	2,088	1,798
Total deferred income tax assets	4,100	3,814
Less valuation allowance	(298)	(147)
Total deferred income tax assets, net	3,802	3,667
Net deferred income tax liabilities, net	(18,800)	(14,690)
Total deferred income tax assets	796	341
Total deferred income tax liabilities	$ (19,596)	$ (15,031)