| | | 2017 | | 2016 | | 2015 | | |||
| Plan assets at fair value as at January 1 | | $ | 267,535 | | | 286,881 | | | 314,804 | |
| Transfer of assets to fund defined contribution benefit plan | | | (10,664) | | | (25,600) | | | (24,187) | |
| Benefits paid by the plan | | | (17,049) | | | (9,457) | | | (10,894) | |
| Expected return on plan assets | | | 23,342 | | | 25,650 | | | 24,901 | |
| Actuarial losses in other comprehensive income | | | (3,919) | | | (9,939) | | | (17,743) | |
| Fair value of plan assets as at December 31 | | $ | 259,245 | | | 267,535 | | | 286,881 | |