XML 88 R47.htm IDEA: XBRL DOCUMENT v3.10.0.1
Post-employee benefit plans - Interest cost (Details) - CAD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Disclosure of net defined benefit liability (asset) [line items]        
Total interest on post-employment benefit obligations $ (17) $ (18) $ (34) $ (36)
DB pension        
Disclosure of net defined benefit liability (asset) [line items]        
Total interest on post-employment benefit obligations (5) (5) (11) (9)
OPEBs        
Disclosure of net defined benefit liability (asset) [line items]        
Total interest on post-employment benefit obligations $ (12) $ (13) $ (23) $ (27)