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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Contingencies - Legal Proceedings (Details) $ in Millions, $ in Millions							3 Months Ended
	Jan. 05, 2024 USD ($)	Oct. 20, 2023 CAD ($)	Aug. 30, 2023 CAD ($)	Jan. 13, 2023 plaintiff	Oct. 20, 2022 CAD ($)	Jan. 24, 2022 procedural_ground	Mar. 31, 2025 CAD ($) claim plaintiff	Mar. 31, 2025 USD ($) claim plaintiff
Damaged rail cars and lost crude recovery
Other Commitments [Line Items]
Damages awarded	$ 3.9
Lac-Megantic Rail Accident
Other Commitments [Line Items]
Number of plaintiffs \| plaintiff				3
Lac-Megantic Rail Accident \| Claimed derailment damages
Other Commitments [Line Items]
Amount of fund to be distributed							$ 440
Lac-Megantic Rail Accident \| Quebec Minister of Sustainable Development, Environment, Wildlife and Parks
Other Commitments [Line Items]
Value of damages sought							95
Lac-Megantic Rail Accident \| Attorney General of Quebec
Other Commitments [Line Items]
Value of damages sought							231
Initial value of damages sought							409
Lac-Megantic Rail Accident \| Initial Subrogated Insurers \| Subrogated insurance claim
Other Commitments [Line Items]
Value of damages sought							14
Initial value of damages sought							$ 16
Number of subrogated insurer claims \| claim							8	8
Lac-Megantic Rail Accident \| Additional Subrogated Insurers \| Subrogated insurance claim
Other Commitments [Line Items]
Value of damages sought							$ 3
Number of subrogated insurer claims \| claim							2	2
Lac-Megantic Rail Accident \| Class Action Plaintiffs
Other Commitments [Line Items]
Value of damages sought							$ 5
Number of plaintiffs \| plaintiff							48	48
Number of plaintiffs who opted out \| plaintiff							2	2
Number of appeals from bankruptcy procedural grounds \| procedural_ground						2
Lac-Megantic Rail Accident \| MMAR Estate Representative \| Damages for loss in business value
Other Commitments [Line Items]
Value of damages sought								$ 30.0
Lac-Megantic Rail Accident \| WD Trustee \| Damaged rail cars and lost crude recovery
Other Commitments [Line Items]
Value of damages sought								6.0
Lac-Megantic Rail Accident \| WD Trustee \| Reimbursement for settlement paid by consignor
Other Commitments [Line Items]
Value of damages sought								110.0
Lac-Megantic Rail Accident \| WD Trustee \| Reimbursement for settlement paid by consignee
Other Commitments [Line Items]
Value of damages sought								$ 60.0
Remington Development Corporation legal claim \| Remington Development Corporation \| Breach of contract
Other Commitments [Line Items]
Damages awarded			$ 165		$ 164
Total estimated damage		$ 230