RESTRICTED LONG-TERM INVESTMENTS (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Long-Lived Assets Held-for-sale [Line Items]
Restricted long-term investments	$ 593	$ 630
Restricted long-term investments (Note 14)	593	630
Debt securities, available-for-sale, amortized cost	437	383
Unrealized holding gains (losses)	(122)	(8)
Future abandonment costs	$ 610	649
Fair Value Recurring Basis Unobservable Input Reconciliation Asset Gain Loss Statement Of Other Comprehensive Income Extensible List Not Disclosed Flag	Restricted long-term investments
Level 1
Long-Lived Assets Held-for-sale [Line Items]
Restricted long-term investments (Note 14)	$ 236	217
Level 2
Long-Lived Assets Held-for-sale [Line Items]
Restricted long-term investments (Note 14)	$ 357	$ 413