REVENUE - Schedule of Recognition and Measurement of Revenues (Details) - CAD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 8,809	$ 6,778
Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	60	69
Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	8,749	6,709
Liquids Pipelines
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,173	3,086
Liquids Pipelines | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
Liquids Pipelines | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,173	3,086
Gas Transmission
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,677	1,519
Gas Transmission | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	24	40
Gas Transmission | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,653	1,479
Gas Distribution and Storage
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,917	2,116
Gas Distribution and Storage | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	36	29
Gas Distribution and Storage | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,881	2,087
Renewable Power Generation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	42	57
Renewable Power Generation | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
Renewable Power Generation | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 42	$ 57