REVENUE (Details) - CAD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									$ 23,916	$ 19,432	$ 18,817
Total operating revenues	$ 13,424	$ 11,573	$ 13,215	$ 15,097	$ 12,470	$ 11,466	$ 10,948	$ 12,187	53,309	47,071	39,087
Mark-to-market (losses)/gains									$ (431)	59	265
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]									Total operating revenues
Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									$ 127	70	60
Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									23,789	19,362	18,757
Transportation revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									17,077	14,532	14,358
Storage and other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									893	648	571
Gas gathering and processing revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									22	49	27
Gas distribution revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									5,643	4,026	3,663
Total operating revenues									5,653	4,026	3,663
Electricity and transmission revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									281	177	198
Commodity sales
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									29,150	26,873	19,259
Total operating revenues									29,150	26,873	19,259
Other Revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									243	766	1,011
Liquids Pipelines
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									11,518	9,639	9,255
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									11,518	9,639	9,255
Gas Transmission and Midstream
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									5,384	4,668	4,824
Gas Transmission and Midstream | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Gas Transmission and Midstream | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									5,384	4,668	4,824
Gas Distribution and Storage
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									6,733	4,948	4,540
Gas Distribution and Storage | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									127	70	60
Gas Distribution and Storage | Transferred Over Time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									6,606	4,878	4,480
Renewable Power Generation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									281	177	198
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									281	177	198
Business Segments | Liquids Pipelines
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									11,518	9,639	9,255
Total operating revenues									12,052	10,581	10,423
Business Segments | Liquids Pipelines | Transportation revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									11,283	9,492	9,161
Business Segments | Liquids Pipelines | Storage and other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									235	147	94
Business Segments | Liquids Pipelines | Gas gathering and processing revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Liquids Pipelines | Gas distribution revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Liquids Pipelines | Electricity and transmission revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Liquids Pipelines | Commodity sales
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									0	0	0
Business Segments | Liquids Pipelines | Other Revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									(81)	375	584
Business Segments | Gas Transmission and Midstream
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									5,384	4,668	4,824
Total operating revenues									5,426	4,711	4,870
Business Segments | Gas Transmission and Midstream | Transportation revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									5,012	4,364	4,523
Business Segments | Gas Transmission and Midstream | Storage and other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									350	255	274
Business Segments | Gas Transmission and Midstream | Gas gathering and processing revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									22	49	27
Business Segments | Gas Transmission and Midstream | Gas distribution revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Gas Transmission and Midstream | Electricity and transmission revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Gas Transmission and Midstream | Commodity sales
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									0	0	0
Business Segments | Gas Transmission and Midstream | Other Revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									39	42	44
Business Segments | Gas Distribution and Storage
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									6,733	4,948	4,540
Total operating revenues									6,729	4,980	4,569
Business Segments | Gas Distribution and Storage | Transportation revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									782	676	674
Business Segments | Gas Distribution and Storage | Storage and other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									308	246	203
Business Segments | Gas Distribution and Storage | Gas gathering and processing revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Gas Distribution and Storage | Gas distribution revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									5,643	4,026	3,663
Business Segments | Gas Distribution and Storage | Electricity and transmission revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Gas Distribution and Storage | Commodity sales
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									0	0	0
Business Segments | Gas Distribution and Storage | Other Revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									(20)	13	17
Business Segments | Renewable Power Generation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									281	177	198
Total operating revenues									582	512	587
Business Segments | Renewable Power Generation | Transportation revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Renewable Power Generation | Storage and other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Renewable Power Generation | Gas gathering and processing revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Renewable Power Generation | Gas distribution revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Renewable Power Generation | Electricity and transmission revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									281	177	198
Business Segments | Renewable Power Generation | Commodity sales
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									0	0	0
Business Segments | Renewable Power Generation | Other Revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									305	336	389
Business Segments | Energy Services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Total operating revenues									29,175	26,917	19,283
Business Segments | Energy Services | Transportation revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Energy Services | Storage and other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Energy Services | Gas gathering and processing revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Energy Services | Gas distribution revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Energy Services | Electricity and transmission revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Business Segments | Energy Services | Commodity sales
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									29,150	26,873	19,259
Business Segments | Energy Services | Other Revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									0	0	0
Eliminations and Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Total operating revenues									(655)	(630)	(645)
Eliminations and Other | Transportation revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Eliminations and Other | Storage and other revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Eliminations and Other | Gas gathering and processing revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Eliminations and Other | Gas distribution revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Eliminations and Other | Electricity and transmission revenue
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers									0	0	0
Eliminations and Other | Commodity sales
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									0	0	0
Eliminations and Other | Other Revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									0	0	(23)
Intersegment revenue
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									(655)	(630)	(622)
Intersegment revenue | Liquids Pipelines
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									615	567	584
Intersegment revenue | Gas Transmission and Midstream
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									3	1	2
Intersegment revenue | Gas Distribution and Storage
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									16	19	12
Intersegment revenue | Renewable Power Generation
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									(4)	(1)	0
Intersegment revenue | Energy Services
Disaggregation of Revenue [Line Items]
Revenue not from contract with customers									$ 25	$ 44	$ 24