OTHER INCOME/(EXPENSE) (Details) - CAD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Other Income and Expenses [Abstract]
Realized foreign currency gain	$ 122	$ 145
Unrealized foreign currency loss	(858)	(188)
Net defined pension and OPEB credit	41	33
Other	144	112
Total	$ (551)	$ 102