Employee Future Benefits - Schedule of Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2023 CAD ($)
Defined Benefit Pension Payments
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2024	$ 184
2025	188
2026	195
2027	200
2028	206
2029-2033	1,113
OPEB Payments
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2024	30
2025	31
2026	32
2027	33
2028	34
2029-2033	$ 187

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- Definition

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

+ Details

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- Definition

Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

+ References

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- Definition

Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

+ References

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Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

+ References

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