v2.4.0.8

Assets and Liabilities with Recurring Fair Value Measurements Quantitative Info on Level 3 (Details) (USD $) | Jun. 30, 2014 | Dec. 31, 2013
--- | --- | ---
Power Contracts [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information Power | $ (22,000,000) | $ 7,000,000
Power Contracts [Member] | Minimum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information Power | 21.41 | 28.92
Power Contracts [Member] | Maximum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information Power | 169.45 | 53.15
Power Congestion Products [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information Power | 7,000,000 | 7,000,000
Power Congestion Products [Member] | Minimum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information Power | (24.07) | (8.79)
Power Congestion Products [Member] | Maximum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair Value Inputs Quantitative Information Power | $ 77.80 | $ 11.53

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- Definition Fair Value Inputs Quantitative Information Power + References No definition available. + Details
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Namespace Prefix: | cpn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration