Debt - Components of Long-term Debt - B (Narrative) (Detail) - Secured Equipment Loan [Member] - CAD CAD in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Floating interest rate		1.74%	1.89%	1.93%
Floating interest rate, margin rate		53.00%
Final repayment of principal amount	CAD 53
Maturity		2015-08