XML 144 R116.htm IDEA: XBRL DOCUMENT v3.8.0.1
Risk Management Activities - Net Risk Management Assets and Liabilities (Details)
CAD in Millions, $ in Millions
Dec. 31, 2017
CAD
Mar. 31, 2017
CAD
Mar. 31, 2017
USD ($)
Dec. 31, 2016
CAD
Disclosure of detailed information about financial instruments [line items]        
Derivative hedge, notional amount CAD 690      
Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 762     CAD 920
Not designated as a hedge | Financial Liabilities        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 52      
Not designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       (16)
Commodity risk management        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       744
Commodity risk management | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 728      
Commodity risk management | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 81     70
Commodity risk management | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 647     674
Commodity risk management | Not designated as a hedge        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       (25)
Commodity risk management | Not designated as a hedge | Financial Liabilities        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 18      
Commodity risk management | Not designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 7      
Commodity risk management | Not designated as a hedge | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 11     (9)
Commodity risk management | Not designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       (16)
Other        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       176
Other | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 34      
Other | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 37     113
Other | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic (3)     63
Other | Not designated as a hedge | Financial Liabilities        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       9
Other | Not designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       8
Other | Not designated as a hedge | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       1
Other | Not designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 34      
Other | Not designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 37      
Other | Not designated as a hedge | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic (3)      
Cash flow hedges | Designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 710     933
Cash flow hedges | Commodity risk management | Designated as a hedge        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       769
Cash flow hedges | Commodity risk management | Designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 710      
Cash flow hedges | Commodity risk management | Designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 74     86
Cash flow hedges | Commodity risk management | Designated as a hedge | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 636     683
Cash flow hedges | Other | Designated as a hedge        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       164
Cash flow hedges | Other | Designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0      
Cash flow hedges | Other | Designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0     105
Cash flow hedges | Other | Designated as a hedge | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0     59
Fair value hedges | Designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0     3
Fair value hedges | Commodity risk management | Designated as a hedge        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       0
Fair value hedges | Commodity risk management | Designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0      
Fair value hedges | Commodity risk management | Designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0     0
Fair value hedges | Commodity risk management | Designated as a hedge | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0     0
Fair value hedges | Other | Designated as a hedge        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic       3
Fair value hedges | Other | Designated as a hedge | Financial Assets        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0      
Fair value hedges | Other | Designated as a hedge | Current        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic 0     0
Fair value hedges | Other | Designated as a hedge | Long-term        
Disclosure of detailed information about financial instruments [line items]        
Risk exposure associated with instruments sharing characteristic CAD 0     CAD 3
Long-term debt | Discontinued Cash Flow Hedge Position [Member] | Interest rate risk        
Disclosure of detailed information about financial instruments [line items]        
Derivative hedge, notional amount | $     $ 690  
Long-term debt | Discontinued Hedge Positions [Member] | Interest rate risk        
Disclosure of detailed information about financial instruments [line items]        
Derivative hedge, notional amount   CAD 50