SEGMENTED INFORMATION (Details) - CAD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segmented Information
Revenues	$ 12,013	$ 12,856
Commodity and gas distribution costs	(8,018)	(7,772)
Operating and administrative	(1,600)	(1,625)
Income/(loss) from equity investments	163	413
Impairment of equity investments	(1,736)	0
Other income/(expense)	(1,147)	260
Earnings/(loss) before interest, income taxes, and depreciation and amortization	(325)	4,132
Depreciation and amortization	(882)	(840)
Interest expense	(706)	(685)
Income tax expense	549	(584)
Earnings/(loss)	(1,364)	2,023
Capital expenditures	1,158	1,627
Intersegment Eliminations
Segmented Information
Revenues	(111)	(136)
Commodity and gas distribution costs	104	128
Operating and administrative	99	58
Income/(loss) from equity investments	0	1
Impairment of equity investments	0
Other income/(expense)	(1,058)	197
Earnings/(loss) before interest, income taxes, and depreciation and amortization	(966)	248
Capital expenditures	22	25
Liquids Pipelines | Business segments
Segmented Information
Revenues	1,534	2,658
Commodity and gas distribution costs	(7)	(6)
Operating and administrative	(865)	(801)
Income/(loss) from equity investments	197	197
Impairment of equity investments	0
Other income/(expense)	(9)	24
Earnings/(loss) before interest, income taxes, and depreciation and amortization	850	2,072
Capital expenditures	500	1,020
Gas Transmission and Midstream | Business segments
Segmented Information
Revenues	1,357	1,318
Commodity and gas distribution costs	0	0
Operating and administrative	(507)	(513)
Income/(loss) from equity investments	(75)	197
Impairment of equity investments	(1,736)
Other income/(expense)	(93)	18
Earnings/(loss) before interest, income taxes, and depreciation and amortization	(1,054)	1,020
Capital expenditures	391	394
Gas Distribution and Storage | Business segments
Segmented Information
Revenues	1,682	2,191
Commodity and gas distribution costs	(872)	(1,264)
Operating and administrative	(249)	(294)
Income/(loss) from equity investments	23	11
Impairment of equity investments	0
Other income/(expense)	20	18
Earnings/(loss) before interest, income taxes, and depreciation and amortization	604	662
Capital expenditures	222	173
Renewable Power Generation and Transmission | Business segments
Segmented Information
Revenues	153	152
Commodity and gas distribution costs	0	(1)
Operating and administrative	(50)	(42)
Income/(loss) from equity investments	16	14
Impairment of equity investments	0
Other income/(expense)	1	1
Earnings/(loss) before interest, income taxes, and depreciation and amortization	120	124
Capital expenditures	23	14
Energy Services | Business segments
Segmented Information
Revenues	7,398	6,673
Commodity and gas distribution costs	(7,243)	(6,629)
Operating and administrative	(28)	(33)
Income/(loss) from equity investments	2	(7)
Impairment of equity investments	0
Other income/(expense)	(8)	2
Earnings/(loss) before interest, income taxes, and depreciation and amortization	121	6
Capital expenditures	$ 0	$ 1