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Change in Plan Assets and Plan Assets in Excess of Less Than Projected Benefit Obligation (Detail) - CAD ($)
$ in Millions

12 Months Ended

Dec. 31, 2019

Dec. 31, 2018

Schedule Of Defined Benefit Plans Disclosures [Line Items]

Fair value at January 1

$ 7,691

Fair value at December 31

8,599

$ 7,691

Pension benefits

Schedule Of Defined Benefit Plans Disclosures [Line Items]

Fair value at January 1

7,691

7,870

Actual return (loss) on plan assets

1,114

20

Company contributions

211

203

Benefits paid

^[1]

(417)

(402)

Fair value at December 31

8,599

7,691

Funded plans

(590)

(180)

Unfunded plans

(597)

(488)

Total

^[2]

(1,187)

(668)

Other postretirement benefits

Schedule Of Defined Benefit Plans Disclosures [Line Items]

Unfunded plans

(693)

(582)

Total

^[2]

$ (693)

$ (582)

[1]	Benefit payments for funded plans only.
[2]	Fair value of assets less projected benefit obligation shown above.

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