DEBT - Schedule of Long-Term Debt Repayments (Details) $ in Millions, $ in Millions	1 Months Ended																				6 Months Ended	7 Months Ended				12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 CAD ($)	Nov. 30, 2019 CAD ($)	Sep. 30, 2019 USD ($)	May 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Feb. 28, 2019 USD ($)	Feb. 28, 2019 CAD ($)	Jan. 31, 2019 CAD ($)	Dec. 31, 2018 CAD ($)	Nov. 30, 2018 CAD ($)	Oct. 31, 2018 USD ($)	Oct. 31, 2018 CAD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2018 CAD ($)	Aug. 31, 2018 CAD ($)	Jul. 31, 2018 USD ($)	Apr. 30, 2018 USD ($)	Apr. 30, 2018 CAD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 CAD ($)	Dec. 31, 2019 USD ($)	Nov. 30, 2019 CAD ($)	Dec. 31, 2018 USD ($)	Nov. 30, 2018 CAD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 CAD ($)	Dec. 31, 2018 CAD ($)
Enbridge Energy Partners, L.P. | 8.05% fixed/floating rate junior subordinated notes due 2067
Debt Instrument [Line Items]
Interest rate (percent)							8.05%	8.05%
Extinguishment of debt							$ 400
Enbridge Energy Partners, L.P. | 5.20% senior notes due 2020
Debt Instrument [Line Items]
Interest rate (percent)	5.20%	5.20%																			5.20%	5.20%				5.20%	5.20%
Extinguishment of debt	$ 500
Cash Consideration	$ 504
Enbridge Energy Partners, L.P. | 4.38% senior notes due 2020
Debt Instrument [Line Items]
Interest rate (percent)	4.38%	4.38%																			4.38%	4.38%				4.38%	4.38%
Extinguishment of debt	$ 500
Cash Consideration	$ 509
Enbridge Energy Partners, L.P. | 9.88% senior notes
Debt Instrument [Line Items]
Interest rate (percent)						9.88%
Extinguishment of debt						$ 500
Enbridge Energy Partners, L.P. | 6.50% senior notes
Debt Instrument [Line Items]
Interest rate (percent)																		6.50%	6.50%
Extinguishment of debt																		$ 400
Enbridge Energy Partners, L.P. | 7.00% senior notes
Debt Instrument [Line Items]
Interest rate (percent)												7.00%	7.00%
Extinguishment of debt												$ 100
Enbridge Income Fund | 4.00% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)										4.00%														4.00%				4.00%
Extinguishment of debt										$ 125
Enbridge Pipelines (Southern Lights) L.L.C. | 3.98% senior notes due 2040
Debt Instrument [Line Items]
Interest rate (percent)	3.98%	3.98%								3.98%											3.98%	3.98%		3.98%		3.98%	3.98%	3.98%
Extinguishment of debt																						$ 49		$ 43
Enbridge Pipelines Inc. | 4.49% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)			4.49%																				4.49%
Extinguishment of debt			$ 200
Enbridge Pipelines Inc. | 4.49% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)			4.49%																				4.49%
Extinguishment of debt			$ 100
Enbridge Pipelines Inc. | 6.62% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)											6.62%														6.62%
Extinguishment of debt											$ 170
Enbridge Pipelines Inc. | 6.62% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)											6.62%														6.62%
Extinguishment of debt											$ 130
Enbridge Southern Lights LP | 4.01% senior notes due 2040
Debt Instrument [Line Items]
Interest rate (percent)	4.01%	4.01%																			4.01%	4.01%				4.01%	4.01%
Extinguishment of debt																					$ 17
Enbridge Southern Lights LP | 4.01% senior notes due 2040
Debt Instrument [Line Items]
Interest rate (percent)										4.01%														4.01%				4.01%
Extinguishment of debt																												$ 27
Midcoast Energy Partner L.P. | 3.56% senior notes due 2019
Debt Instrument [Line Items]
Interest rate (percent)																	3.56%
Extinguishment of debt																	$ 75
Cash Consideration																	$ 76
Midcoast Energy Partner L.P. | 4.04% senior notes due 2021
Debt Instrument [Line Items]
Interest rate (percent)																	4.04%
Extinguishment of debt																	$ 175
Cash Consideration																	$ 182
Midcoast Energy Partner L.P. | 4.42% senior notes due 2024
Debt Instrument [Line Items]
Interest rate (percent)																	4.42%
Extinguishment of debt																	$ 150
Cash Consideration																	$ 161
Spectra Energy Capital, LLC
Debt Instrument [Line Items]
Loss on extinguishment of debt																										$ 50	$ 64
Spectra Energy Capital, LLC | 6.75% senior unsecured notes due 2032
Debt Instrument [Line Items]
Interest rate (percent)																				6.75%
Extinguishment of debt																				$ 64
Cash Consideration																				$ 80
Spectra Energy Capital, LLC | 7.50% senior unsecured notes due 2038
Debt Instrument [Line Items]
Interest rate (percent)																				7.50%
Extinguishment of debt																				$ 43
Cash Consideration																				$ 59
Spectra Energy Capital, LLC | 5.65% senior unsecured notes due 2020
Debt Instrument [Line Items]
Interest rate (percent)																				5.65%
Extinguishment of debt																				$ 163
Cash Consideration																				$ 172
Spectra Energy Capital, LLC | 3.30% senior unsecured notes due 2023
Debt Instrument [Line Items]
Interest rate (percent)																				3.30%
Extinguishment of debt																				$ 498
Cash Consideration																				$ 508
Spectra Energy Capital, LLC | 6.20% senior notes
Debt Instrument [Line Items]
Interest rate (percent)																		6.20%	6.20%
Extinguishment of debt																		$ 272
Spectra Energy Capital, LLC | 6.75% senior notes
Debt Instrument [Line Items]
Interest rate (percent)																	6.75%
Extinguishment of debt																	$ 118
Spectra Energy Partners, LP | 2.95% senior notes
Debt Instrument [Line Items]
Interest rate (percent)														2.95%	2.95%
Extinguishment of debt														$ 500
Union Gas Limited | 5.35% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)																		5.35%	5.35%
Extinguishment of debt																			$ 200
Union Gas Limited | 8.75% debentures
Debt Instrument [Line Items]
Interest rate (percent)																8.75%
Extinguishment of debt																$ 125
Union Gas Limited | 8.65% senior debentures
Debt Instrument [Line Items]
Interest rate (percent)												8.65%	8.65%
Extinguishment of debt													$ 75
Westcoast Energy Inc. | 5.60% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)									5.60%
Extinguishment of debt									$ 250
Westcoast Energy Inc. | 5.60% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)									5.60%
Extinguishment of debt									$ 50
Westcoast Energy Inc. | 6.90% senior secured notes
Debt Instrument [Line Items]
Interest rate (percent)			6.90%																				6.90%
Extinguishment of debt																							$ 26
Westcoast Energy Inc. | 4.34% senior secured notes
Debt Instrument [Line Items]
Interest rate (percent)			4.34%																				4.34%
Extinguishment of debt																							$ 5
Westcoast Energy Inc. | 1.00% senior secured notes
Debt Instrument [Line Items]
Interest rate (percent)			1.00%																				1.00%
Extinguishment of debt		$ 2
Westcoast Energy Inc. | 6.90% senior secured notes due 2019
Debt Instrument [Line Items]
Interest rate (percent)											6.90%														6.90%
Extinguishment of debt																									$ 26
Westcoast Energy Inc. | 4.34% senior secured notes due 2019
Debt Instrument [Line Items]
Interest rate (percent)											4.34%														4.34%
Extinguishment of debt																									$ 9
Westcoast Energy Inc. | 8.50% debentures
Debt Instrument [Line Items]
Interest rate (percent)														8.50%	8.50%
Extinguishment of debt															$ 150
Enbridge Inc. | 4.10% medium-term notes
Debt Instrument [Line Items]
Interest rate (percent)							4.10%	4.10%
Extinguishment of debt								$ 300
Enbridge Inc. | Floating rate notes
Debt Instrument [Line Items]
Interest rate (percent)				4.77%
Extinguishment of debt				$ 400
Enbridge Inc. | 5.60% medium-term notes
Debt Instrument [Line Items]
Extinguishment of debt					$ 750