Income taxes - Significant Components of Income Taxes Deducted from Net Earnings (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Current taxes
Current taxes	$ (923)	$ (878)
Uncertain tax positions	8	91
Change in estimate relating to prior periods	9	8
Deferred taxes
Deferred taxes relating to the origination and reversal of temporary differences	(75)	(176)
Change in estimate relating to prior periods	1	(8)
Recognition and utilization of loss carryforwards	(24)	(4)
Uncertain tax positions	8	0
Total income taxes	$ (996)	$ (967)

Adjustments For Current Tax Expense (Income) Of Uncertain Tax Positions

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Adjustments For Deferred Tax Expense (Income) Of Uncertain Tax Positions

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Deferred Tax Expense (Income) Relating To Recognition and Utilization of Loss Carryforwards

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Adjustments of tax expense (income) recognised in the period for current tax of prior periods.

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Adjustments of tax expense (income) recognised in the period for the deferred tax of prior periods.

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The amount of income taxes payable (recoverable) in respect of the taxable profit (tax loss) for a period.

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The amount of deferred tax expense or income relating to the creation or reversal of temporary differences. [Refer: Temporary differences [member]; Deferred tax expense (income)]

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The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax. [Refer: Current tax expense (income); Deferred tax expense (income)]

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