Call Option Exercise Period

No definition available.

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- Definition

Equity Method Investment, Summarized Financial Information, Debt

+ References

No definition available.

+ Details

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- Definition

Minority Interest Ownership Percentage By Noncontrolling Third Party Owners

+ References

No definition available.

+ Details

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- Definition

Power generation capacity

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Put Option Exercise Period

+ References

No definition available.

+ Details

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64801991&loc=SL6759159-111685

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Variable Interest Entities and Unconsolidated Investments (VIE Textuals) (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) yr MW	Dec. 31, 2015 USD ($) MW	Dec. 31, 2014 USD ($)
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity, Financial or Other Support, Amount \| $	$ 115,000,000	$ 4,000,000	$ 47,000,000
Equity Method Investment, Summarized Financial Information, Debt \| $	259,000,000	269,000,000
Prorata Share of Equity Method Investment, Summarized Financial Information, Debt \| $	$ 130,000,000	$ 135,000,000
Greenfield [Member]
Schedule of Equity Method Investments [Line Items]
Minority Interest Ownership Percentage By Noncontrolling Third Party Owners	50.00%
Whitby [Member]
Schedule of Equity Method Investments [Line Items]
Minority Interest Ownership Percentage By Noncontrolling Third Party Owners	50.00%
Russell City Energy [Member]
Schedule of Equity Method Investments [Line Items]
Minority Interest Ownership Percentage By Noncontrolling Third Party Owners	25.00%
Equity Method Investment, Ownership Percentage	75.00%
Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Equity Method Investments [Line Items]
Power generation capacity	9,491	10,266
Inland Empire Energy Center [Member]
Schedule of Equity Method Investments [Line Items]
Power generation capacity	775
Put Option Exercise Period \| yr	2,025
Minimum [Member] \| Inland Empire Energy Center [Member]
Schedule of Equity Method Investments [Line Items]
Call Option Exercise Period \| yr	2,017
Maximum [Member] \| Inland Empire Energy Center [Member]
Schedule of Equity Method Investments [Line Items]
Call Option Exercise Period \| yr	2,024
Greenfield [Member]
Schedule of Equity Method Investments [Line Items]
Power generation capacity	1,038
Equity Method Investment, Ownership Percentage	50.00%
Whitby [Member]
Schedule of Equity Method Investments [Line Items]
Power generation capacity	50
Equity Method Investment, Ownership Percentage	50.00%