| Year ended December 31, | ||||||||||||
| 2017 | 2016 | 2015 | ||||||||||
| U.S. dollars in thousands | ||||||||||||
| Salaries, management and consulting fees and other short-term benefits | 373 | 407 | 487 | |||||||||
| Pension, post retirement and other benefits | 12 | 17 | 16 | |||||||||
| Share-based payments, net | 39 | 127 | 143 | |||||||||
| 424 | 551 | 646 | ||||||||||
| Number of persons | 9 | 10 | 11 | |||||||||