| $000 | | Dec 31, 2017 | | Dec 31, 2016 | | Dec 31, 2015 | | |||
| Total employee benefit cost was as follows: | | | | | | | | | | |
| Short term benefits | | | 75,507 | | | 71,453 | | | 50,199 | |
| Pension contributions | | | 13,665 | | | 11,460 | | | 5,104 | |
| Share-based payments | | | 21,993 | | | 23,891 | | | 22,943 | |
| Total | | | 111,165 | | | 106,804 | | | 78,246 | |