ASSET RETIREMENT OBLIGATIONS (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of movements in the Company's ARO
Obligations at beginning of year	$ 488	$ 502
Liabilities acquired	1	0
Liabilities incurred	0	30
Liabilities settled	(23)	(126)
Change in estimate and other	5	51
Foreign currency translation adjustment	(6)	24
Accretion expense	28	7
Obligations at end of year	493	488
Other current liabilities	136	83
Other long-term liabilities	357	405
Asset retirement obligations	$ 493	$ 488
Minimum
Asset Retirement Obligations [Line Items]
Discount rate (as a percent)	1.50%
Maximum
Asset Retirement Obligations [Line Items]
Discount rate (as a percent)	9.00%