XML 188 R87.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Accounting Changes - Disclosure of comparative information prepared under previous GAAP (Details) - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Jan. 01, 2019
Disclosure of comparative information prepared under previous GAAP [line items]        
Non-cancellable operating leases $ 77 $ 80   $ 83
Profit (loss) [abstract]        
Revenue from contracts with customers 2,347 2,249 $ 2,307  
Fuel and purchased power (1,086) (1,100) (1,016)  
Interest expense (179) (250) (247)  
Net earnings (loss) 176 (90) $ (118)  
Statement of financial position [abstract]        
Deferred income tax liabilities (Note 11) 472 501    
Contract liabilities 14 80    
Deficit $ (1,455) $ (1,496)