XML 153 R101.htm IDEA: XBRL DOCUMENT v3.8.0.1
Financial instruments - Derivatives (Details) - CAD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Disclosure of detailed information about financial instruments [line items]    
Net $ 17,390 $ (48,273)
Gain (loss) 56,250 34,407
Current portion of other liabilities [member]    
Disclosure of detailed information about financial instruments [line items]    
Net (11,249) (24,966)
Other liabilities [Member]    
Disclosure of detailed information about financial instruments [line items]    
Net (12,165) (33,919)
Current portion of long-term receivables, investments and other [member]    
Disclosure of detailed information about financial instruments [line items]    
Net 25,948 4,119
Long-term receivables, investments and other [Member]    
Disclosure of detailed information about financial instruments [line items]    
Net 14,856 6,493
Foreign currency contracts [Member]    
Disclosure of detailed information about financial instruments [line items]    
Net 34,360 (25,166)
Gain (loss) 58,983 59,398
Interest rate swap contracts [member]    
Disclosure of detailed information about financial instruments [line items]    
Net (150) 6,547
Gain (loss) (4,014) (1,016)
Uranium contracts [Member]    
Disclosure of detailed information about financial instruments [line items]    
Net (16,820) (29,654)
Gain (loss) $ 1,281 $ (23,975)