LEASES - Lease Commitments (Details) - CAD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Operating leases
2023	$ 109
2024	110
2025	104
2026	90
2027	82
Thereafter	489
Total undiscounted lease payments	984
Less imputed interest	(220)
Total	764	$ 704
Finance leases
2023	19
2024	16
2025	8
2026	8
2027	1
Thereafter	10
Total undiscounted lease payments	62
Less imputed interest	(6)
Total finance lease liabilities	$ 56	$ 46