| | Balance as of January 1, 2016 | | Addition (reversal) | | Balance as of December 31, 2016 | | Additions | | Sales | | Balance as of December 31, 2017 | | ||||||
| | US$(000) | | US$(000) | | US$(000) | | US$(000) | | US$(000) | | US$(000) | | ||||||
| | | | | | | | | | | | | | | | | | | |
Cost | | | 12,103 | | | (92) | | | 12,011 | | | 157 | | | (11,826) | | | 342 | |
Accumulated depreciation | | | (1,384) | | | (538) | | | (1,922) | | | (462) | | | 2,264 | | | (120) | |
| | | | | | | | | | | | | | | | | | | |
Net cost | | | 10,719 | | | | | | 10,089 | | | | | | | | | 222 | |