Other Long-Term Obligations (Detail) (CAD) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Schedule of Other Liabilities [Line Items]
Employee retirement benefits	2,593	[1]	2,717	[1]
Asset retirement obligations and other environmental liabilities	1,248	[2]	957	[2]
Share-based incentive compensation liabilities	144		117
Other obligations	211		192
Total other long-term obligations	4,196		3,983

[1] Total recorded employee retirement benefits obligations also included $52 million in current liabilities (December 31, 2012 - $52 million).

[2] Total asset retirement obligations and other environmental liabilities also included $168 million in current liabilities (December 31, 2012 - $168 million).