Segment Reporting - Summary of Operating Revenues, Net (Details) - USD ($)
$ in Thousands |
3 Months Ended |
12 Months Ended |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
| Revenue, Major Customer [Line Items] |
|
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| Operating revenues, net |
$ 51,256
|
$ 29,373
|
$ 25,681
|
$ 17,806
|
$ 13,899
|
$ 7,446
|
$ 9,278
|
$ 8,826
|
$ 124,116
|
$ 39,449
|
$ 22,196
|
| Eskom Holdings SOC Limited |
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| Revenue, Major Customer [Line Items] |
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| Operating revenues, net |
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|
44,006
|
7,152
|
|
| Camara de Comercializacao de Energia Eletrica |
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| Revenue, Major Customer [Line Items] |
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| Operating revenues, net |
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18,910
|
|
|
| Gujarat Urja Vikas Nigam Limited |
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| Revenue, Major Customer [Line Items] |
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| Operating revenues, net |
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|
|
|
|
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17,593
|
4,535
|
4,419
|
| Inner Mongolia Power (group) Co., LTD. |
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| Revenue, Major Customer [Line Items] |
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| Operating revenues, net |
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$ 12,298
|
|
|
| NTPC Vidyut Vyapar Nigam Limited |
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| Revenue, Major Customer [Line Items] |
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| Operating revenues, net |
|
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|
|
|
|
|
|
|
9,657
|
$ 10,187
|
| Malaysia Airports (Sepang) Sdn Bhd |
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| Revenue, Major Customer [Line Items] |
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| Operating revenues, net |
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$ 5,034
|
|
| Customer concentration risk | Operating revenue, net | Eskom Holdings SOC Limited |
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| Revenue, Major Customer [Line Items] |
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| Concentration risk |
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35.00%
|
18.00%
|
|
| Customer concentration risk | Operating revenue, net | Camara de Comercializacao de Energia Eletrica |
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| Revenue, Major Customer [Line Items] |
|
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| Concentration risk |
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|
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|
15.00%
|
|
|
| Customer concentration risk | Operating revenue, net | Gujarat Urja Vikas Nigam Limited |
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| Revenue, Major Customer [Line Items] |
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| Concentration risk |
|
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|
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|
14.00%
|
11.00%
|
20.00%
|
| Customer concentration risk | Operating revenue, net | Inner Mongolia Power (group) Co., LTD. |
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| Revenue, Major Customer [Line Items] |
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| Concentration risk |
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10.00%
|
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| Customer concentration risk | Operating revenue, net | NTPC Vidyut Vyapar Nigam Limited |
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| Revenue, Major Customer [Line Items] |
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| Concentration risk |
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|
24.00%
|
46.00%
|
| Customer concentration risk | Operating revenue, net | Malaysia Airports (Sepang) Sdn Bhd |
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| Revenue, Major Customer [Line Items] |
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| Concentration risk |
|
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|
|
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13.00%
|
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