Derivative financial instruments, Breakdown of fair value amounts (Details) - Cash Flow Hedge [Member] - USD ($) $ in Thousands |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Breakdown of fair value amount of derivative financial instruments [Abstract] | ||
| Assets | $ 1,559 | $ 5,230 |
| Liabilities | 328,184 | 298,744 |
| Interest Rate Derivatives [Member] | ||
| Breakdown of fair value amount of derivative financial instruments [Abstract] | ||
| Assets | 898 | 1,619 |
| Liabilities | 302,302 | 298,744 |
| Foreign Exchange Derivative Instruments [Member] | ||
| Breakdown of fair value amount of derivative financial instruments [Abstract] | ||
| Assets | 661 | 3,610 |
| Liabilities | 0 | 0 |
| Notes Conversion Option [Member] | ||
| Breakdown of fair value amount of derivative financial instruments [Abstract] | ||
| Assets | 0 | 0 |
| Liabilities | $ 25,882 | $ 0 |