Pensions and other postretirement benefits (Details 5) (CAD) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Pensions [Member]
Amounts recognized in Accumulated Other Comprehensive Loss Before Tax [Line Items]
Net actuarial gain (loss)	(1,515)	(3,264)
Prior service cost	(22)	(26)
Other postretirement benefits [Member]
Amounts recognized in Accumulated Other Comprehensive Loss Before Tax [Line Items]
Net actuarial gain (loss)	27	6
Prior service cost	(5)	(6)

Amount related to the pretax cost of benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as components of net periodic benefit cost.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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