v3.19.2
employee future benefits - Defined benefit pension plans expense (Details) - CAD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Defined benefit pension plan expense (recovery)        
Total $ 19 $ 24 $ 39 $ 49
Pension plans | Pension plan        
Defined benefit pension plan expense (recovery)        
Current service cost 18 23 36 45
Past service costs       1
Interest expense arising from defined benefit obligations accrued 83 79 167 158
Return, including interest income, on plan assets (217) (229) (662) (243)
Interest effect on asset ceiling limit 3 1 5 2
Total (131) (149) (490) (83)
Administrative fees 1 1 3 3
Changes in the effect of limiting net defined benefit assets to the asset ceiling 115 9 441 9
Total 3 (116) (10) (25)
Pension plans | Pension plan | Employee benefits expense        
Defined benefit pension plan expense (recovery)        
Current service cost 18 23 36 45
Past service cost       1
Administrative fees 1 1 3 3
Total 19 24 39 49
Pension plans | Pension plan | Financing costs        
Defined benefit pension plan expense (recovery)        
Interest expense arising from defined benefit obligations accrued 83 79 167 158
Return, including interest income, on plan assets (86) (77) (172) (153)
Interest effect on asset ceiling limit 3 1 5 2
Total   3   7
Total   3   7
Pension plans | Pension plan | Other comprehensive income        
Defined benefit pension plan expense (recovery)        
Return, including interest income, on plan assets (131) (152) (490) (90)
Total (131) (152) (490) (90)
Changes in the effect of limiting net defined benefit assets to the asset ceiling 115 9 441 9
Defined benefit pension plan expense (recovery) $ (16) $ (143) $ (49) $ (81)