RISK MANAGEMENT AND FINANCIAL INSTRUMENTS - Effects on Earnings and Comprehensive Income (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of unrealized gain/(loss) recognized in OCI	$ 282	$ 1,062	$ 191
Amount of loss reclassified from AOCI to earnings	$ 28	203	304
Period to hedge exposures to the variability of cash flows for all forecasted transactions	2 years
Cash flow hedges
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Loss from AOCI expected to be reclassified	$ 18
Foreign exchange contracts
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of loss reclassified from AOCI to earnings	0	13	5
Foreign exchange contracts \| Cash flow hedges
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of unrealized gain/(loss) recognized in OCI	0	3	(29)
Foreign exchange contracts \| Fair value hedges
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of unrealized gain/(loss) recognized in OCI	15	(35)	(5)
Interest rate contracts
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of loss reclassified from AOCI to earnings	28	186	296
Interest rate contracts \| Cash flow hedges
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of unrealized gain/(loss) recognized in OCI	201	1,151	252
Commodity contracts
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of loss reclassified from AOCI to earnings	0	0	1
Commodity contracts \| Cash flow hedges
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of unrealized gain/(loss) recognized in OCI	68	(53)	(28)
Other contracts
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of loss reclassified from AOCI to earnings	0	4	2
Other contracts \| Cash flow hedges
The Effect of Derivative Instruments on the Statements of Earnings and Comprehensive Income
Amount of unrealized gain/(loss) recognized in OCI	$ (2)	$ (4)	$ 1

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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