Trade and other receivables (Details) - USD ($) $ in Thousands |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Trade and other receivables [Abstract] | ||
| Trade receivables | $ 227,343 | $ 258,087 |
| Tax receivables | 59,350 | 50,663 |
| Prepayments | 9,342 | 12,074 |
| Other accounts receivable | 11,108 | 10,911 |
| Trade and other receivables | 307,143 | 331,735 |
| Euros [Member] | ||
| Trade and other receivables [Abstract] | ||
| Trade receivables | 65,854 | 105,826 |
| South African Rand [Member] | ||
| Trade and other receivables [Abstract] | ||
| Trade receivables | 24,513 | 24,121 |
| Other [Member] | ||
| Trade and other receivables [Abstract] | ||
| Trade receivables | 13,330 | 6,929 |
| All Foreign Currencies [Member] | ||
| Trade and other receivables [Abstract] | ||
| Trade receivables | $ 103,697 | $ 136,876 |