The total grant date fair value of equity settled awards determined by using valuation models.

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The weighted average fair value at grant date for outstanding equity-based awards 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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No definition available.

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Number of units to be settled from the Share Trusts in the next fiscal year.

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The number of units settled/paid out 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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No definition available.

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The weighted-average grant date fair value of units settled during the period.

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No definition available.

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Share-Based Compensation Arrangement By Share-Based payment Award, Non-Option Equity Instruments, Weighted Average Grant Date Fair Value [Abstract]

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 2
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Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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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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The weighted average fair value at grant date for nonvested equity-based awards issued 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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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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Description of method used to estimate fair value of award under share-based payment arrangement.

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Number of shares under non-option equity instrument agreements that were cancelled as a result of occurrence of a terminating event.

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Net number of non-option equity instruments granted to participants.

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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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

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Stock-based Compensation (PSU Table) (Details) - CAD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Remittance of stock-based award participants' withholding tax obligation		$ 44	$ 37	$ 48
Share Units Plan [Member] \| Equity Settled Awards [Member] \| PSU-ROIC [Member]
Roll forward of outstanding PSUs
Units outstanding at beginning of period (in shares)	0.8	0.8
Units granted (in shares)		0.2
Units settled (in shares)		(0.3)
Units forfeited (in shares)		0.0
Units outstanding at end of period (in shares)		0.7	0.8
Weighted-average grant date fair value
Weighted-average grant date fair value at beginning of period (in dollars per share)	$ 69.84	$ 69.84
Weighted-average grant date fair value of units granted in period (in dollars per share)		81.03
Weighted-average grant date fair value of units settled in period (in dollars per share)		70.79
Weighted-average grant date fair value of units forfeited in period (in dollars per share)		72.85
Weighted-average grant date fair value at end of period (in dollars per share)		$ 73.21	$ 69.84
Roll forward of nonvested PSUs
Units nonvested at beginning of period (in shares)	0.5	0.5
Units granted in period (in shares)		0.2
Units vested during the year (in shares)		(0.2)
Units forfeited in period (in shares)		0.0
Units nonvested at end of period (in shares)		0.5	0.5
Weighted-average grant date fair value
Weighted-average grant date fair value at beginning of period (in dollars per share)	$ 69.27	$ 69.27
Weighted-average grant date fair value of units granted in period (in dollars per share)		81.03
Weighted-average grant date fair value of units vested in period (in dollars per share)		73.92
Weighted-average grant date fair value of units forfeited in period (in dollars per share)		72.85
Weighted-average grant date fair value at end of period (in dollars per share)		$ 72.78	$ 69.27
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Grant date fair value		$ 20
Valuation method used in calculating the fair value of PSUs		lattice-based
Unrecognized compensation costs, awards other than options		$ 14
Unrecognized compensation cost, period of recognition		1 year 8 months 12 days
Share Units Plan [Member] \| Equity Settled Awards [Member] \| PSU-ROIC [Member] \| 2019 Grant Year [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Performance vesting factor		83.00%
Share Units Plan [Member] \| Equity Settled Awards [Member] \| PSU-TSR [Member]
Roll forward of outstanding PSUs
Units outstanding at beginning of period (in shares)	0.4	0.4
Units granted (in shares)		0.1
Units settled (in shares)		(0.1)
Units forfeited (in shares)		0.0
Units outstanding at end of period (in shares)		0.4	0.4
Weighted-average grant date fair value
Weighted-average grant date fair value at beginning of period (in dollars per share)	$ 144.37	$ 144.37
Weighted-average grant date fair value of units granted in period (in dollars per share)		180.18
Weighted-average grant date fair value of units settled in period (in dollars per share)		128.22
Weighted-average grant date fair value of units forfeited in period (in dollars per share)		160.82
Weighted-average grant date fair value at end of period (in dollars per share)		$ 160.40	$ 144.37
Roll forward of nonvested PSUs
Units nonvested at beginning of period (in shares)	0.3	0.3
Units granted in period (in shares)		0.1
Units vested during the year (in shares)		(0.2)
Units forfeited in period (in shares)		0.0
Units nonvested at end of period (in shares)		0.2	0.3
Weighted-average grant date fair value
Weighted-average grant date fair value at beginning of period (in dollars per share)	$ 150.59	$ 150.59
Weighted-average grant date fair value of units granted in period (in dollars per share)		180.18
Weighted-average grant date fair value of units vested in period (in dollars per share)		153.00
Weighted-average grant date fair value of units forfeited in period (in dollars per share)		160.82
Weighted-average grant date fair value at end of period (in dollars per share)		$ 164.20	$ 150.59
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Grant date fair value		$ 23
Valuation method used in calculating the fair value of PSUs		Monte Carlo
Unrecognized compensation costs, awards other than options		$ 16
Unrecognized compensation cost, period of recognition		1 year 10 months 24 days
Share Units Plan [Member] \| Equity Settled Awards [Member] \| PSU-TSR [Member] \| 2019 Grant Year [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Performance vesting factor		72.00%
Share Units Plan [Member] \| Equity Settled Awards [Member] \| PSU-ROIC and PSU-TSR [Member] \| 2019 Grant Year [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]
Remittance of stock-based award participants' withholding tax obligation	$ 23
Settlement from the Share Trusts in next fiscal year (in shares)	0.2