Project debt, Movement in project debt and Significant foreign currency denominated debts (Details) - USD ($) $ in Thousands |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|---|
| Project debt [Abstract] | |||
| Project debt | $ 5,237,614 | $ 4,852,348 | $ 5,091,114 |
| Euro [Member] | |||
| Project debt [Abstract] | |||
| Project debt | 2,240,811 | 1,882,618 | |
| South African Rand [Member] | |||
| Project debt [Abstract] | |||
| Project debt | 355,414 | 384,313 | |
| Algerian Dinar [Member] | |||
| Project debt [Abstract] | |||
| Project debt | 115,606 | 24,331 | |
| All Foreign Currencies [Member] | |||
| Project debt [Abstract] | |||
| Project debt | $ 2,711,830 | $ 2,291,262 |