v3.6.0.2

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Information about Level 3 Fair Value Measurements (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net	$ 162,000,000	$ (196,000,000)
Physical Power [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net	360,000,000	(54,000,000)
Physical Power [Member] | Minimum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	9.60	6.72
Physical Power [Member] | Maximum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	86.34	83.25
Natural Gas [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net	17,000,000
Natural Gas [Member] | Minimum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	1.95
Natural Gas [Member] | Maximum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	11.23
Power Congestion Products [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Derivative, Fair Value, Net	12,000,000	8,000,000
Power Congestion Products [Member] | Minimum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	(7.52)	(11.47)
Power Congestion Products [Member] | Maximum [Member]
Quantitative Information about Level 3 fair Value Measurements [Line Items]
Fair Value Inputs Quantitative Information	$ 13.62	$ 12.19

X

- Definition

Fair Value Inputs Quantitative Information

+ References

No definition available.

+ Details

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Namespace Prefix:	cpn_
Data Type:	xbrli:monetaryItemType
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X

- 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=73719730&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=73719730&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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