LEASES - Lessor Lease Income (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease income	$ 241	$ 266	$ 263
Variable lease income	299	321	333
Total lease income	$ 540	$ 587	$ 596
Operating lease income comprehensive income extensible list not disclosed flag	Total lease income1	Total lease income1	Total lease income1