Income Taxes - Narrative (Details) - CAD	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized tax benefits from capital losses	CAD 0	CAD 0
Effect of tax rate increases	0	23,000,000	CAD 0
Income tax operating losses carried forward	48,000,000
Minimum tax credits	1,000,000
Total amount of accrued interest and penalties	(1,000,000)	(4,000,000)	(1,000,000)
The total amount of accrued interest and penalties associated with unrecognized tax benefit	CAD 10,000,000	CAD 9,000,000	CAD 5,000,000