|
Variable Interest Entities and Unconsolidated Investments (Unconsolidated Investements) (Details) (USD $)
|
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2012
|
Mar. 31, 2011
|
|
| Income Loss from Unconsolidated Investments in Power Plants and Distributions [Line Items] | ||
| (Income) loss from unconsolidated investments in power plants | $ (9,000,000) | $ (9,000,000) |
|
Greenfield [Member]
|
||
| Income Loss from Unconsolidated Investments in Power Plants and Distributions [Line Items] | ||
| (Income) loss from unconsolidated investments in power plants | (6,000,000) | (5,000,000) |
| Return on investment in unconsolidated subsidiaries | 0 | 0 |
|
Whitby [Member]
|
||
| Income Loss from Unconsolidated Investments in Power Plants and Distributions [Line Items] | ||
| (Income) loss from unconsolidated investments in power plants | (3,000,000) | (4,000,000) |
| Return on investment in unconsolidated subsidiaries | $ 0 | $ 0 |