XML 171 R143.htm IDEA: XBRL DOCUMENT v3.20.4
Goodwill (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2020
CAD ($)
cADPerMegawattHour
Dec. 31, 2019
CAD ($)
cADPerMegawattHour
Disclosure of detailed information about intangible assets [line items]    
Goodwill $ 463 $ 464
Hydro generation    
Disclosure of detailed information about intangible assets [line items]    
Goodwill 258 258
Wind and Solar    
Disclosure of detailed information about intangible assets [line items]    
Goodwill 175 176
Energy Marketing    
Disclosure of detailed information about intangible assets [line items]    
Goodwill $ 30 $ 30
Minimum    
Disclosure of detailed information about intangible assets [line items]    
Electricity prices | cADPerMegawattHour 6 5
Discount rate used to calculate goodwill impairment 4.80% 3.60%
Maximum    
Disclosure of detailed information about intangible assets [line items]    
Electricity prices | cADPerMegawattHour 160 183
Discount rate used to calculate goodwill impairment 6.30% 7.00%