OTHER INCOME/(EXPENSE) (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other Income and Expenses [Abstract]
Gain/(loss) on dispositions	$ 15	$ (12)	$ 319
Realized foreign currency gain/(loss)	(129)	92	126
Unrealized foreign currency gain/(loss)	821	(1,094)	160
Net defined pension and OPEB credit	135	239	150
Other	382	186	224
Total	$ 1,224	$ (589)	$ 979