Change in Projected Benefit Obligation (Detail) (CAD) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Pension benefits
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation at January 1	7,336		6,646
Current service cost	181		160		122
Interest cost	281		288		314
Actuarial loss/(gain)	(504)		616
Amendments
Benefits paid	(424)	[1]	(374)	[1]
Projected benefit obligation at December 31	6,870		7,336		6,646
Accumulated benefit obligation at December 31	6,263		6,560
Other post-retirement benefits
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation at January 1	547		508
Current service cost	11		8		6
Interest cost	21		21		23
Actuarial loss/(gain)	(50)		40
Amendments
Benefits paid	(26)	[1]	(30)	[1]
Projected benefit obligation at December 31	503		547		508

[1] Benefit payments for funded and unfunded plans.