Employee benefit plans - Weighted average asset allocations (Details) |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Defined Benefit Plan | ||
| Percentage of plan assets | 100.00% | 100.00% |
| Canadian equity | ||
| Defined Benefit Plan | ||
| Percentage of plan assets | 30.00% | 29.00% |
| U.S. equity | ||
| Defined Benefit Plan | ||
| Percentage of plan assets | 14.00% | 14.00% |
| International equity | ||
| Defined Benefit Plan | ||
| Percentage of plan assets | 14.00% | 13.00% |
| Canadian fixed income | ||
| Defined Benefit Plan | ||
| Percentage of plan assets | 39.00% | 41.00% |
| Real estate equities | ||
| Defined Benefit Plan | ||
| Percentage of plan assets | 3.00% | 3.00% |