INTANGIBLE ASSETS - Schedule of Intangible Assets (Details) - CAD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
INTANGIBLE ASSETS
Cost	$ 7,130	$ 5,552
Accumulated Amortization	(2,543)	(2,015)
Net	$ 4,587	$ 3,537
Software
INTANGIBLE ASSETS
Weighted Average Amortization Rate	10.90%	12.00%
Cost	$ 2,109	$ 1,921
Accumulated Amortization	(1,222)	(1,090)
Net	$ 887	$ 831
Power purchase agreements
INTANGIBLE ASSETS
Weighted Average Amortization Rate	4.50%	4.30%
Cost	$ 58	$ 58
Accumulated Amortization	(26)	(24)
Net	$ 32	$ 34
Project agreement
INTANGIBLE ASSETS
Weighted Average Amortization Rate	4.00%	4.00%
Cost	$ 173	$ 158
Accumulated Amortization	(52)	(41)
Net	$ 121	$ 117
Customer relationships
INTANGIBLE ASSETS
Weighted Average Amortization Rate	8.60%	8.60%
Cost	$ 2,856	$ 2,636
Accumulated Amortization	(975)	(675)
Net	$ 1,881	$ 1,961
Biogas rights agreements
INTANGIBLE ASSETS
Weighted Average Amortization Rate	3.40%
Cost	$ 999
Accumulated Amortization	(34)
Net	$ 965
Other intangible assets
INTANGIBLE ASSETS
Weighted Average Amortization Rate	5.80%	8.20%
Cost	$ 665	$ 603
Accumulated Amortization	(234)	(185)
Net	$ 431	$ 418
Under development
INTANGIBLE ASSETS
Weighted Average Amortization Rate	0.00%	0.00%
Cost	$ 270	$ 176
Accumulated Amortization	0	0
Net	$ 270	$ 176