Schedule of Unconditional Purchase Obligations (Detail) (CAD) In Millions, unless otherwise specified	Dec. 31, 2013
Unrecorded Unconditional Purchase Obligation [Line Items]
Unconditional purchase obligations payments due 2014	91	[1]
Unconditional purchase obligations payments due 2015	80	[1]
Unconditional purchase obligations payments due 2016	82	[1]
Unconditional purchase obligations payments due 2017	83	[1]
Unconditional purchase obligations payments due 2018	84	[1]
Unconditional purchase obligations payments due after 2018	237	[1]
Unconditional Purchase Obligation, Total	657	[1]

[1] Undiscounted obligations of $657 million mainly pertain to pipeline throughput agreements. Total payments under unconditional purchase obligations were $95 million (2012 - $86 million, 2011 - $73 million). The present value of these commitments, excluding imputed interest of $178 million, totalled $479 million.