DEBT - Narrative (Details)						3 Months Ended	6 Months Ended
	Jul. 24, 2020 CAD ($)	Jul. 08, 2020 USD ($)	Mar. 31, 2020 CAD ($)	Feb. 25, 2020 USD ($) credit_facility	Feb. 24, 2020 USD ($)	Jun. 30, 2020 CAD ($)	Jun. 30, 2020 CAD ($)	Apr. 09, 2020 CAD ($)	Dec. 31, 2019 CAD ($)
Line of Credit Facility [Line Items]
Commitment fee percentage							0.20%
Long-term debt						$ 63,680,000,000	$ 63,680,000,000		$ 59,661,000,000
Long-term debt, fair value adjustment							810,000,000
Amortization of fair value adjustment						14,000,000	29,000,000
Commercial paper and credit facility draws
Line of Credit Facility [Line Items]
Long-term debt						9,365,000,000	9,365,000,000		8,974,000,000
60-year Hybrid Subordinated Notes | Subordinated term notes | Subsequent event
Line of Credit Facility [Line Items]
Term of debt instrument		60 years
Principal amount of debt		$ 1,000,000,000.0
Earliest redemption year		10 years
60-year Hybrid Subordinated Notes | Subordinated term notes | Initial 10 years | Subsequent event
Line of Credit Facility [Line Items]
Initial period with a fixed interest rate		10 years
Interest rate (as a percent)		5.75%
60-year Hybrid Subordinated Notes | Subordinated term notes | Years 10 to 30 | 5-year United States Treasury rate | Subsequent event
Line of Credit Facility [Line Items]
Spread on variable rate (percent)		5.31%
Variable rate reset period		5 years
60-year Hybrid Subordinated Notes | Subordinated term notes | Years 30 to 60 | 5-year United States Treasury rate | Subsequent event
Line of Credit Facility [Line Items]
Spread on variable rate (percent)		6.06%
Variable rate reset period		5 years
Fixed-to-floating subordinated term notes | Subordinated term notes
Line of Credit Facility [Line Items]
Subordinated debt						6,758,000,000	6,758,000,000		6,550,000,000
Committed credit facilities
Line of Credit Facility [Line Items]
Amount of credit facility						24,504,000,000	24,504,000,000
Unutilized amount of facility						14,102,000,000	14,102,000,000
Non-revolving credit facility
Line of Credit Facility [Line Items]
Amount of credit facility					$ 1,000,000,000
Term of debt instrument					2 years
Non-revolving, bilateral credit facility
Line of Credit Facility [Line Items]
Amount of credit facility				$ 500,000,000
Number of credit facilities | credit_facility				2
Term of debt instrument				1 year
Revolving credit facility
Line of Credit Facility [Line Items]
Amount of credit facility			$ 1,700,000,000					$ 3,000,000,000.0
Term of debt instrument			1 year
Revolving credit facility | Extendible Credit Facility | Subsequent event
Line of Credit Facility [Line Items]
Term out provision	1 year
Term of debt instrument	364 days
Portion of credit facility extended	$ 10,000,000,000
Uncommitted demand credit facilities
Line of Credit Facility [Line Items]
Amount of credit facility						795,000,000	795,000,000		916,000,000
Unutilized amount of facility						519,000,000	$ 519,000,000		$ 476,000,000
Enbridge Pipelines Inc. | Committed credit facilities
Line of Credit Facility [Line Items]
Term out provision							1 year
Amount of credit facility						3,000,000,000	$ 3,000,000,000
Unutilized amount of facility						1,015,000,000	$ 1,015,000,000
Enbridge Gas Inc. | Committed credit facilities
Line of Credit Facility [Line Items]
Term out provision							1 year
Amount of credit facility						2,000,000,000	$ 2,000,000,000
Unutilized amount of facility						$ 1,645,000,000	$ 1,645,000,000