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Financial assets and other receivables - Other financial assets (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2018
Disclosure of financial assets [line items] |  |
Other non-current financial assets held with third parties | $ 89,315 | $ 70,343
Other current financial assets held with third parties | 2,469 | 2,523
Other total financial assets held with third parties | 91,784 | 72,866
Impairment on non-recoverable loans and receivables | 4,462 |
Investment in subordinated loan notes | 82,638 |
Other financial assets |  |
Disclosure of financial assets [line items] |  |
Other non-current financial assets held with third parties | 86,234 |
Other current financial assets held with third parties | 2,469 |
Other total financial assets held with third parties | 88,703 |
Amortised cost | Other financial assets |  |
Disclosure of financial assets [line items] |  |
Other non-current financial assets held with third parties |  | 3,264
Other total financial assets held with third parties |  | 3,264
Fair value through other comprehensive income - designated | Equity securities |  |
Disclosure of financial assets [line items] |  |
Other current financial assets held with third parties |  | 2,523
Other total financial assets held with third parties |  | 2,523
Fair value through profit or loss - mandatorily measured | Debt investments |  |
Disclosure of financial assets [line items] |  |
Other non-current financial assets held with third parties |  | 67,079
Other total financial assets held with third parties |  | $ 67,079
Loans and receivables |  |
Disclosure of financial assets [line items] |  |
Other non-current financial assets held with third parties | 3,081 |
Other total financial assets held with third parties | $ 3,081 |

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