| 8. | Intangible assets |
| Costs: | | | |
| Balance as of January 1, 2015 | | 10,987 | |
| Additions | | - | |
| Disposals | | (211) | |
| Balance as of December 31, 2015 | | 10,776 | |
| Additions | | 3,111 | |
| Disposals | | (4) | |
| Balance as of December 31, 2016 | | 13,883 | |
| Additions | | 3,370 | |
| Disposals | | (81) | |
| Balance as of December 31, 2017 | | 17,172 | |
| | | | |
| Accumulated amortization: | | | |
| Balance as of January 1, 2015 | | 9,963 | |
| Disposals | | (210) | |
| Amortization expense of the year | | 596 | |
| Balance as of December 31, 2015 | | 10,349 | |
| Disposals | | (4) | |
| Amortization expense of the year | | 629 | |
| Balance as of December 31, 2016 | | 10,974 | |
| Disposals | | (65) | |
| Amortization expense of the year | | 838 | |
| Balance as of December 31, 2017 | | 11,747 | |
| | | | |
| Carrying amounts as of: | | | |
| December 31, 2017 | | 5,425 | |
| December 31, 2016 | | 2,909 | |
| December 31, 2015 | | 427 | |