v2.3.0.11

Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified | 6 Months Ended |  |
--- | --- | --- | ---
Jun. 30, 2011 | Dec. 31, 2010 | Jul. 02, 2010
Commitments and Contingencies [Abstract] |  |  |
Environmental remediation liabilities related to Acquisition |  |  | $ 10
Amount of expenditures over which PHI is responsible for related to the Conectiv Acquisition |  |  | $ 10
Deepwater Unit 1 amount of MWs under full capacity | 8 |  |
Limitation on Full Capacity of Deepwater Unit 1 | 78 |  |
Amount of shares distributed to holders of allowed unsecured claims | 464 |  |
Amount of shares remaining in reserve for distribution to holders of disputed claims | 21 |  |
Amount of shares authorized to settle unsecured claims | 485 |  |
Commitments and Contingencies [Line Items] |  |  |
Power generation capacity (in Megawatts) | 11,064 | 13,553 |
Deepwater Unit 1 |  |  |
Commitments and Contingencies [Line Items] |  |  |
Power generation capacity (in Megawatts) | 86 |  |

X
- Definition Amount Of Expenditures Third Party Is Responsible For Related To Acquisition + Details
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Namespace Prefix: | cpn
Data Type: | xbrli:monetaryItemType
Balance Type: | na
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X
- Definition Amount Of Megawatts Under Full Capacity + Details
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Namespace Prefix: | cpn
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of shares authorized to settle unsecured claims + Details
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Namespace Prefix: | cpn
Data Type: | xbrli:sharesItemType
Balance Type: | na
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X
- Definition Amount Of Shares Distributed To Holders Of Allowed Unsecured Claims + Details
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X
- Definition Amount of shares remaining in reserve for distribution to holders of disputed claims + Details
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Balance Type: | na
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X
- Definition Commitments and Contingencies Line Items + Details
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Namespace Prefix: | cpn
Data Type: | xbrli:stringItemType
Balance Type: | na
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X
- Definition Environmental remediation liabilities related to Acquisition + Details
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Namespace Prefix: | cpn
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Power generation capacity + Details
Name: | cpn_PowerGenerationCapacity
Namespace Prefix: | cpn
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Power generation capacity limitation + Details
Name: | cpn_PowerGenerationCapacityLimitation
Namespace Prefix: | cpn
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
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