Amounts Reclassified Out of Accumulated Other Comprehensive Income (Detail) (Reclassification Adjustment out of Accumulated Other Comprehensive Income, CAD) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of post-retirement benefits liability adjustment included in net periodic benefit cost	(276)	[1]	(266)	[1]	(186)	[1]

[1] This accumulated other comprehensive income component is included in the computation of net periodic benefit cost (note 4).