leases (Details) - CAD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Income from subleasing right-of-use lease assets | ||||
| Portion of real estate right-of-use assets that are subleased, as a percent | 20.00% | |||
| Co-location sublet revenue included in operating service revenues | $ 4 | $ 4 | $ 9 | $ 9 |
| Lease payments | $ 81 | $ 68 | $ 184 | $ 136 |