v3.3.1.900

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Information about Level 3 Fair Value Measurements (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net	$ (196,000,000)	$ 271,000,000
Physical Power [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net	(54,000,000)	74,000,000
Physical Power [Member] | Minimum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	6.72	14.00
Physical Power [Member] | Maximum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	$ 83.25	122.79
Natural Gas [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net		5,000,000
Natural Gas [Member] | Minimum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information		1
Natural Gas [Member] | Maximum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information		10.86
Power Congestion Products [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net	$ 8,000,000	9,000,000
Power Congestion Products [Member] | Minimum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	(11.47)	(19.56)
Power Congestion Products [Member] | Maximum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	$ 12.19	$ 19.56

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- Definition

Fair Value Inputs Quantitative Information

+ References

No definition available.

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- Definition

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13495-108611

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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.

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