Number of additional Performance Deferred Share Units that can be granted as a percentage of units originally granted

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- Definition

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

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- Definition

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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No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

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.

+ References

No definition available.

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- Definition

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

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 2
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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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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, 2023	Mar. 31, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 13		$ 21	$ 84	$ 67
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options issued (in shares)				856,332
Options issued, weighted average price per share (In Canadian dollars per share)				$ 105.82
Stock option weighted average price (in Canadian dollars per share)				$ 29.79
Expiration period				7 years
Stock options grant date fair value				$ 26
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				12 months
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				48 months
Performance Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued (in shares)				891,411			489,990
Grant date fair value				$ 96
PSU payout percentage						180.00%
Number of trading days						30 days
Units paid in period (in shares)		459,358
Value of shares vested		$ 87
Performance Share Units (PSUs) \| January 1, 2023 to December 31, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued (in shares)				544,175
Performance Share Units (PSUs) \| April 28, 2023 to December 1, 2026
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued (in shares)				347,236
Performance Deferred Share Units (PDSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued (in shares)				26,333			50,145
Grant date fair value				$ 3
Number of additional PDSUs that can be granted as a % of original units granted	25.00%			25.00%
Units paid in period (in shares)		45,058
Payout in future periods		$ 11
PSUs and PDSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
PSUs and PDSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years