Pensions and other postretirement benefits (Details 4) (CAD) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Amounts Recognized In Consolidated Balance Sheet [Line Items]
Noncurrent assets (Note 6)	0	442
Current liabilities (Note 7)	(18)	(18)
Noncurrent liabilities	(1,095)	(510)
Pensions [Member]
Amounts Recognized In Consolidated Balance Sheet [Line Items]
Noncurrent assets (Note 6)	0	442
Noncurrent liabilities	(829)	(245)
Total amount recognized	(829)	197
Other Postretirement Benefit Plans Defined Benefit [Member]
Amounts Recognized In Consolidated Balance Sheet [Line Items]
Current liabilities (Note 7)	(18)	(18)
Noncurrent liabilities	(266)	(265)
Total amount recognized	(284)	(283)

The amount for overfunded plans recognized in the balance sheet as a noncurrent asset associated with a defined benefit pension plan or other postretirement defined benefit plan.

+ References+ Details

For a classified balance sheet, the amount recognized in balance sheet as a current liability associated with an underfunded defined benefit plan.

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- Definition

This represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans.

+ References

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

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

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

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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+ Details