REVENUE - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2022 CAD ($)	Sep. 30, 2022 CAD ($)
Revenue from Contract with Customer [Abstract]
Revenue recognized	$ 57	$ 139
Increase in contract with customers, liability	138	366
Remaining performance obligation	59,300	59,300
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 1,900	$ 1,900
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, period	3 months	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 6,400	$ 6,400
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, period	1 year	1 year