As of December 31, | |||||||||
2017 | 2016 | 2015 | |||||||
Balance at beginning of year | 1,945 | 650 | 794 | ||||||
Additions | 527 | 1,343 | 490 | ||||||
Additions related to business combinations (note 23) | — | 817 | — | ||||||
Recovery | — | (344 | ) | (253 | ) | ||||
Utilization of provision for contingencies | (1,320 | ) | (400 | ) | (91 | ) | |||
Foreign exchange | 27 | (121 | ) | (290 | ) | ||||
Balance at end of year | 1,179 | 1,945 | 650 |