|
Variable Interest Entities and Unconsolidated Investments (Consolidation of VIE) (Details)
|
Mar. 31, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Schedule of Equity Method Investments [Line Items] | ||
| Power generation capacity | 11,392 | 11,391 |
| Power generation capacity under construction | 773 | 584 |
|
Whitby [Member]
|
||
| Schedule of Equity Method Investments [Line Items] | ||
| Power generation capacity | 50 | |
| Equity Method Investment, Ownership Percentage | 50.00% | |
|
Russell City Project [Member]
|
||
| Schedule of Equity Method Investments [Line Items] | ||
| Power generation capacity | 619 | |
| Equity Method Investment, Ownership Percentage | 75.00% | |
| Minority Interest Ownership Percentage By Noncontrolling Third Party Owners | 25.00% | |
|
Los Esteros Project [Member]
|
||
| Schedule of Equity Method Investments [Line Items] | ||
| Power generation capacity | 188 | |
| Power generation capacity after upgrade | 309 |