Change in Plan Assets and Plan Assets in Excess of Less Than Projected Benefit Obligation (Detail) (CAD) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value at December 31	5,872		5,114
Pension benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value at January 1	5,114		4,461
Actual return/(loss) on plan assets	491		374
Company contributions	600		594
Benefits paid	(333)	[1]	(315)	[1]
Fair value at December 31	5,872		5,114
Funded plans	(424)		(1,602)
Unfunded plans	(574)		(620)
Total	(998)	[2]	(2,222)	[2]
Other post-retirement benefits
Defined Benefit Plan Disclosure [Line Items]
Unfunded plans	(503)		(547)
Total	(503)	[2]	(547)	[2]

[1] Benefit payments for funded plans only.

[2] Fair value of assets less projected benefit obligation shown above.