v3.26.1
REVENUE - Schedule of Major Products and Services (Details) - CAD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers $ 8,968 $ 8,777
Total revenue 22,357 18,502
Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 2,857 3,173
Gas Transmission    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 1,696 1,677
Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 4,338 3,885
Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 77 42
Transportation revenue    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 4,329 4,659
Storage and other revenue    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 404 398
Gas distribution sales    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 4,113 3,654
Gas distribution revenue    
Disaggregation of Revenue [Line Items]    
Total revenue 4,139 3,699
Electricity revenue    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 77 42
Commodity sales    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 45 24
Revenue not from contract with customers 13,147 9,525
Other Revenue    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 242 200
Business Segments    
Disaggregation of Revenue [Line Items]    
Total revenue 21,825 17,975
Business Segments | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 2,857 3,173
Total revenue 15,462 12,184
Business Segments | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 1,696 1,677
Total revenue 1,781 1,715
Business Segments | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 4,338 3,885
Total revenue 4,408 3,956
Business Segments | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 77 42
Total revenue 174 120
Business Segments | Transportation revenue | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 2,795 3,105
Business Segments | Transportation revenue | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 1,471 1,480
Business Segments | Transportation revenue | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 63 74
Business Segments | Transportation revenue | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Storage and other revenue | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 62 68
Business Segments | Storage and other revenue | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 187 173
Business Segments | Storage and other revenue | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 155 157
Business Segments | Storage and other revenue | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Gas distribution sales | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Gas distribution sales | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Gas distribution sales | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 4,113 3,654
Business Segments | Gas distribution sales | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Electricity revenue | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Electricity revenue | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Electricity revenue | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Business Segments | Electricity revenue | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 77 42
Business Segments | Commodity sales | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Revenue not from contract with customers 12,539 8,934
Business Segments | Commodity sales | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 38 24
Revenue not from contract with customers 49 37
Business Segments | Commodity sales | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 7 0
Revenue not from contract with customers 0 0
Business Segments | Commodity sales | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Revenue not from contract with customers 0 0
Business Segments | Other Revenue | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 66 77
Business Segments | Other Revenue | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 30 (7)
Business Segments | Other Revenue | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 52 53
Business Segments | Other Revenue | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 94 77
Eliminations and Other    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Total revenue 532 527
Eliminations and Other | Transportation revenue    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Eliminations and Other | Storage and other revenue    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Eliminations and Other | Gas distribution sales    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Eliminations and Other | Electricity revenue    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Eliminations and Other | Commodity sales    
Disaggregation of Revenue [Line Items]    
Total revenue from contracts with customers 0 0
Revenue not from contract with customers 559 554
Eliminations and Other | Other Revenue    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 0 0
Intersegment revenue    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers (27) (27)
Intersegment revenue | Liquids Pipelines    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 0 0
Intersegment revenue | Gas Transmission    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 6 8
Intersegment revenue | Gas Distribution and Storage    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers 18 18
Intersegment revenue | Renewable Power Generation    
Disaggregation of Revenue [Line Items]    
Revenue not from contract with customers $ 3 $ 1