REVENUE - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2024 CAD ($)	Jun. 30, 2024 CAD ($)
Revenue from Contract with Customer [Abstract]
Revenue recognized	$ 82	$ 233
Increase in contract with customers, liability	149	266
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	59,700	59,700
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 4,100	$ 4,100
Remaining performance obligation, period	6 months	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 8,200	$ 8,200
Remaining performance obligation, period	1 year	1 year