VARIABLE INTEREST ENTITIES - Schedule of the Carrying Amount of Interest in VIEs (Details) $ in Millions	Dec. 31, 2023 CAD ($)	Nov. 15, 2023	Dec. 31, 2022 CAD ($) project
Fox Squirrel Solar LLC
VARIABLE INTEREST ENTITY
Ownership interest (as a percent)		50.00%
Variable Interest Entity, Not Primary Beneficiary
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE	$ 1,909		$ 1,616
Maximum exposure to loss	4,647		4,466
Variable Interest Entity, Not Primary Beneficiary | Aux Sable Liquid Products L.P.
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE	105		91
Maximum exposure to loss	130		117
Variable Interest Entity, Not Primary Beneficiary | EIH S.a.r.l.
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE			37
Maximum exposure to loss			$ 637
Number of offshore wind projects | project			3
Variable Interest Entity, Not Primary Beneficiary | EIH S.a.r.l. | Affiliated Entity
VARIABLE INTEREST ENTITY
Affiliate loan receivable			$ 56
Variable Interest Entity, Not Primary Beneficiary | Rampion Offshore Wind Limited
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE	391		413
Maximum exposure to loss	452		468
Variable Interest Entity, Not Primary Beneficiary | Vector Pipeline L.P.
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE	191		195
Maximum exposure to loss	320		325
Credit facility provided	105		105
Variable Interest Entity, Not Primary Beneficiary | Vector Pipeline L.P. | Affiliated Entity
VARIABLE INTEREST ENTITY
Affiliate loan receivable	24		25
Variable Interest Entity, Not Primary Beneficiary | Woodfibre LNG LP
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE	778		635
Maximum exposure to loss	2,854		2,476
Variable Interest Entity, Not Primary Beneficiary | Fox Squirrel Solar LLC
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE	312
Maximum exposure to loss	661
Variable Interest Entity, Not Primary Beneficiary | Other
VARIABLE INTEREST ENTITY
Carrying amount of investment in VIE	132		245
Maximum exposure to loss	$ 230		$ 443