2017 | 2016 | 2015 | ||||
Accounts receivable | 29,547 | 12,392 | (55,458 | ) | ||
Inventory | 15,437 | (9,893 | ) | (6,370 | ) | |
Prepaid expenses and other current assets | 981 | 10,801 | (14,738 | ) | ||
Accounts payable and accrued liabilities | (9,483 | ) | (1,380 | ) | (2,054 | ) |
Provisions | 5,988 | (5,637 | ) | 10,930 | ||
Other liabilities | (30 | ) | (195 | ) | 155 | |
Changes in non-cash working capital | 42,440 | 6,088 | (67,535 | ) | ||