Call Option Exercise Period

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- Definition

Equity Method Investment, Summarized Financial Information, Debt

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- Definition

Equity Method Investment, Summarized Financial Information, Term Loan

+ References

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- Definition

Equity Method Investment, Summarized Financial Information, Term Loan Period

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- Definition

Power generation capacity

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- Definition

Project financing interest rate spread - Canadian LIBOR

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- Definition

Project financing interest rate spread - Canadian Prime Rate

+ References

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- Definition

Prorata Share of Equity Method Investment, Summarized Financial Information, Debt

+ References

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- Definition

Put Option Exercise Period

+ References

No definition available.

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- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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-Number 210

-Section 03

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-Article 7

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-Publisher FASB

-Name Statement of Financial Accounting Concepts (CON)

-Number 6

-Paragraph 25

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-Name Regulation S-X (SX)

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-Publisher FASB

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- Definition

This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities.

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Article 5

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-Name Statement of Financial Accounting Standard (FAS)

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

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-Name Statement of Financial Accounting Standard (FAS)

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-Topic 323

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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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- Definition

The cash inflow from the sale of property, plant and equipment (capital expenditures), software, and other intangible assets.

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-Name Statement of Financial Accounting Standard (FAS)

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The amount of financial or other support the reporting entity has provided (explicitly or implicitly) to the Variable Interest Entity (VIE) that it was not previously contractually required to provide or that the reporting entity intends to provide, including, for example, situations in which the reporting entity assisted the VIE in obtaining another type of support.

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Variable Interest Entities and Unconsolidated Investments (VIE Textuals) (Details) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended						3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended
	Jun. 30, 2012 USD ($) MW	Jun. 30, 2011 USD ($)	Jun. 30, 2012 USD ($) MW	Jun. 30, 2011 USD ($)	Dec. 31, 2011 USD ($) MW	Jun. 30, 2012 Inland Empire Energy Center [Member] MW	Jun. 30, 2012 Inland Empire Energy Center [Member] Minimum [Member]	Jun. 30, 2012 Inland Empire Energy Center [Member] Maximum [Member]	Jun. 30, 2012 Greenfield [Member] USD ($)	Jun. 30, 2011 Greenfield [Member] USD ($)	Jun. 30, 2012 Greenfield [Member] USD ($)	Jun. 30, 2011 Greenfield [Member] USD ($)	Jun. 30, 2012 Greenfield [Member] CAD MW	Jun. 30, 2012 Whitby [Member] USD ($) MW	Jun. 30, 2011 Whitby [Member] USD ($)	Jun. 30, 2012 Whitby [Member] USD ($) MW	Jun. 30, 2011 Whitby [Member] USD ($)	Jun. 30, 2012 Riverside Energy Center [Member] USD ($) MW
Variable Interest Entity [Line Items]
Power generation capacity	10,500		10,500		11,391	775							1,038	50		50		603
Proceeds from Sale of Productive Assets																		$ 392
Assets	16,887		16,887		17,371													422
Liabilities	13,184		13,184		13,007													5
Variable Interest Entity, Financial or Other Support, Amount	0	0	0	72
Equity Method Investment, Ownership Percentage													50.00%	50.00%		50.00%
Equity Method Investment, Summarized Financial Information, Debt	448		448		462
Prorata Share of Equity Method Investment, Summarized Financial Information, Debt	224		224		231
Equity Method Investment, Summarized Financial Information, Term Loan Period													18
Equity Method Investment, Summarized Financial Information, Term Loan													648
Project financing interest rate spread - Canadian LIBOR													1.125%
Project financing interest rate spread - Canadian Prime Rate													0.125%
Return on investment in unconsolidated subsidiaries									$ 9	$ 2	$ 9	$ 2		$ 7	$ 4	$ 7	$ 4
Call Option Exercise Period							2,017	2,024
Put Option Exercise Period						2,025