v2.4.0.8

Shareholder Transaction (Details) (USD $)	Sep. 30, 2014
Shareholder Transaction [Abstract]
Shareholder Ownership Percentage	10.00%
Common Stock Purchased from Shareholder	13,213,372
Purchase Price of Common Stock Purchased from Shareholder	$ 311,464,283

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- Definition

Common Stock Purchased from Shareholder

+ References

No definition available.

+ Details

Name:	cpn_CommonStockPurchasedfromShareholder
Namespace Prefix:	cpn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

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- Definition

Purchase Price of Common Stock Purchased from Shareholder

+ References

No definition available.

+ Details

Name:	cpn_PurchasePriceofCommonStockPurchasedfromShareholder
Namespace Prefix:	cpn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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- Definition

Shareholder Ownership Percentage

+ References

No definition available.

+ Details

Name:	cpn_ShareholderOwnershipPercentage
Namespace Prefix:	cpn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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- Details

Name:	cpn_ShareholderTransactionAbstract
Namespace Prefix:	cpn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration