Stockholders' Equity Stockholders' Equity - Summary of Noncontrolling Interest Balances By Projects (Details) - USD ($) $ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
Sep. 30, 2015 |
Dec. 31, 2014 |
|---|---|---|---|---|
| Noncontrolling Interest [Line Items] | ||||
| Noncontrolling interest | $ 906,685 | $ 944,262 | $ 810,712 | $ 530,586 |
| El Arrayan [Member] | ||||
| Noncontrolling Interest [Line Items] | ||||
| Noncontrolling interest | 32,125 | 34,224 | ||
| Logan's Gap [Member] | ||||
| Noncontrolling Interest [Line Items] | ||||
| Noncontrolling interest | 183,681 | 190,397 | ||
| Panhandle One [Member] | ||||
| Noncontrolling Interest [Line Items] | ||||
| Noncontrolling interest | 192,117 | 195,791 | ||
| Panhandle Two [Member] | ||||
| Noncontrolling Interest [Line Items] | ||||
| Noncontrolling interest | 173,841 | 184,773 | ||
| Post Rock [Member] | ||||
| Noncontrolling Interest [Line Items] | ||||
| Noncontrolling interest | 185,636 | 196,346 | ||
| Amazon Wind Farm Flower Ridge [Member] | ||||
| Noncontrolling Interest [Line Items] | ||||
| Noncontrolling interest | $ 139,285 | $ 142,731 |