REGULATORY MATTERS - Schedule of Regulatory Assets and Liabilities (Details) - CAD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Regulatory Assets [Line Items]
Total current regulatory assets (Note9)	$ 604	$ 259
Total long - term regulatory assets	5,863	5,606
Regulatory assets	6,467	5,865
Regulatory Liabilities [Line Items]
Total current regulatory liabilities	167	106
Total long - term regulatory liabilities	3,624	3,321
Total regulatory liabilities	3,791	3,427
Other regulatory assets (liabilities)
Regulatory Liabilities [Line Items]
Total current regulatory liabilities	167	106
Total long - term regulatory liabilities	250	234
Future removal and restoration reserves
Regulatory Liabilities [Line Items]
Total long - term regulatory liabilities	1,615	1,543
U.S income Taxes
Regulatory Liabilities [Line Items]
Total long - term regulatory liabilities	918	895
Pipeline future abandonment costs (Note 14)
Regulatory Liabilities [Line Items]
Total long - term regulatory liabilities	610	649
Pension plans and OPEB
Regulatory Liabilities [Line Items]
Total long - term regulatory liabilities	231	0
Purchase gas variance
Regulatory Assets [Line Items]
Total current regulatory assets (Note9)	190	15
Total long - term regulatory assets	244	215
Under-recovery of fuel costs
Regulatory Assets [Line Items]
Total current regulatory assets (Note9)	109	114
Other regulatory assets (liabilities)
Regulatory Assets [Line Items]
Total current regulatory assets (Note9)	305	130
Total long - term regulatory assets	244	339
Deferred income taxes
Regulatory Assets [Line Items]
Total long - term regulatory assets	4,473	4,176
Long-term debt
Regulatory Assets [Line Items]
Total long - term regulatory assets	378	398
Negative salvage
Regulatory Assets [Line Items]
Total long - term regulatory assets	265	243
Accounting policy changes
Regulatory Assets [Line Items]
Total long - term regulatory assets	219	157
Pension plans and OPEB
Regulatory Assets [Line Items]
Total long - term regulatory assets	$ 40	$ 78