Electric Customer Credits (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Electric Customer Credits [Abstract]
Target return on equity allowed by FRP (in hundredths)	10.70%
Percentage of retail earnings due to customers (in hundredths)	60.00%
Return on equity for customer credit, low range (in hundredths)	11.30%
Return on equity for customer credit, high range (in hundredths)	12.30%
Provision of rate refund	$ 14,854	$ 9,598	$ 9,000

- Definition

The target return on equity allowed by the current Formula Rate Plan as established by the Louisiana Public Service Commission.

+ Details

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- Definition

The percentage of retail earnings to be returned to retail customers, as per the Formula Rate Plan, when the return on equity falls between a certain range.

+ Details

Name:	cnl_PercentageOfRetailEarningsDueToCustomers
Namespace Prefix:	cnl
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- Definition

The high range of the return on equity which triggers a retail customer partial refund obligation. All retail earnings must be returned to customers when the return on equity exceeds this high range.

+ Details

Name:	cnl_ReturnOnEquityForCustomerCreditHighRange
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- Definition

The low range of the return on equity which triggers a retail customer partial refund obligation.

+ Details

Name:	cnl_ReturnOnEquityForCustomerCreditLowRange
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- Definition

Current regulatory liabilities generally represent obligations to make refunds to customers for various reasons including overpayment.

+ Details

Name:	us-gaap_CustomerRefundLiabilityCurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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