XML 138 R123.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
POST-EMPLOYMENT BENEFITS - Benefit Plan Costs (Details) - Domestic defined benefit plans - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [line items]    
Current service cost $ 121 $ 143
Past service recovery (21) (43)
Net interest cost 8 12
Net pension expense 108 112
Administrative expense 4 4
Total pension cost recognized in net income 112 116
Plan assets    
Disclosure of net defined benefit liability (asset) [line items]    
Net interest cost (81) (73)
Administrative expense 3 3
Accrued benefit obligation    
Disclosure of net defined benefit liability (asset) [line items]    
Current service cost 121 143
Past service recovery (21) (43)
Net interest cost $ 89 $ 85