The details of intangible assets are as follows:
| Classes of intangible assets | Classes of intangible assets | |||||||||||||||
| (net) | (gross) | |||||||||||||||
| As of | As of | As of | As of | |||||||||||||
| December 31, | December 31, | December 31, | December 31, | |||||||||||||
| 2017 | 2016 | 2017 | 2016 | |||||||||||||
| ThUS$ | ThUS$ | ThUS$ | ThUS$ | |||||||||||||
| Airport slots | 964,513 | 978,849 | 964,513 | 978,849 | ||||||||||||
| Loyalty program | 321,440 | 326,262 | 321,440 | 326,262 | ||||||||||||
| Computer software | 160,970 | 157,016 | 509,377 | 419,652 | ||||||||||||
| Developing software | 123,415 | 91,053 | 123,415 | 91,053 | ||||||||||||
| Trademarks (1) | 46,909 | 57,133 | 62,539 | 63,730 | ||||||||||||
| Other assets | - | - | - | 808 | ||||||||||||
| Total | 1,617,247 | 1,610,313 | 1,981,284 | 1,880,354 | ||||||||||||