Financial Instruments and Risk Management - Non Designated Derivative Financial Instruments (Details) - Non-Designated Derivative Financial Instruments - At fair value - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Financial Instruments and Risk Management
Fair value outstanding, beginning of year	$ (65)	$ (98)
Changes in fair value recognized in earnings during the year	25	(187)
Cash settlements - paid (received) during the year	20	220
Fair value outstanding, end of year	$ (20)	$ (65)

The amount of assets less the amount of liabilities.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 1
-IssueDate 2023-01-01
-Paragraph IG63
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=1&code=ifrs-tx-2023-en-r&anchor=para_IG63&doctype=Implementation%20Guidance
-URIDate 2023-03-23

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2023-03-23

Name:	ifrs-full_NetAssetsLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant