REVENUES - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2023 CAD ($)	Jun. 30, 2023 CAD ($)
Revenue from Contract with Customer [Abstract]
Revenue recognized	$ 53	$ 89
Increase in contract with customers, liability	43	167
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	57,900	57,900
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3,900	$ 3,900
Remaining performance obligation, period	6 months	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 6,700	$ 6,700
Remaining performance obligation, period	1 year	1 year