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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Grant Date Fair Value

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Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Issued, Weighted Average Price

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Trading Days Used to Calculate Average Share Price

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Amount of cash paid to settle liability for award under share-based payment arrangement.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Gross number of share options (or share units) granted during the period.

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- Definition

Percentage of vesting of award under share-based payment arrangement.

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Intrinsic value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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No definition available.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Value, before forfeiture, of shares granted under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).

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No definition available.

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Stock-based compensation - Narrative (Details) - CAD ($) $ / shares in Units, $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 52		$ 13	$ 120	$ 84
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options issued (in shares)				817,609
Options issued, weighted average price per share (In cad per share)				$ 113.77
Expiration period (in years)				7 years
Stock options grant date fair value				$ 27
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				12 months
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				48 months
Performance Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued (in shares)				568,159			431,430
Grant date fair value				$ 65
PSU payout percentage				135.00%
Number of trading days				30 days
Units paid in period (in shares)		399,372
Performance Share Units (PSUs) \| Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash payout		$ 54
Performance Share Units (PSUs) \| Performance Period One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued (in shares)				568,159
Performance Deferred Share Units (PDSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued (in shares)				25,589			12,694
Grant date fair value				$ 3
Number of units that can be granted as percentage of shares acquired	25.00%			25.00%
Units paid in period (in shares)						11,372
Payout in future periods						$ 2
PSUs and PDSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				3 years
PSUs and PDSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)				4 years