REVENUE - Recognition and Measurement of Revenues (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 25,939	$ 24,199	$ 23,916
Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	295	155	127
Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	25,644	24,044	23,789
Liquids Pipelines
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	12,213	12,132	11,518
Liquids Pipelines | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0
Liquids Pipelines | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	12,213	12,132	11,518
Gas Transmission
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	6,010	5,780	5,384
Gas Transmission | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	158	17	0
Gas Transmission | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,852	5,763	5,384
Gas Distribution and Storage
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	7,527	6,028	6,733
Gas Distribution and Storage | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	137	138	127
Gas Distribution and Storage | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	7,390	5,890	6,606
Renewable Power Generation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	189	259	281
Renewable Power Generation | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0
Renewable Power Generation | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 189	$ 259	$ 281