Net Income Per Share (Detail) (CAD) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income per common share - basic
Net income (millions of dollars)	2,828	3,766	3,371
Weighted average number of common shares outstanding (millions of shares)	847.6	847.7	847.7
Net income per common share (dollars)	3.34	4.44	3.98
Net income per common share - diluted
Net income (millions of dollars)	2,828	3,766	3,371
Weighted average number of common shares outstanding (millions of shares)	847.6	847.7	847.7
Effect of employee share-based awards (millions of shares)	3.0	3.4	5.9
Weighted average number of common shares outstanding, assuming dilution (millions of shares)	850.6	851.1	853.6
Net income per common share (dollars)	3.32	4.42	3.95