Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2012
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements of Cleco include the accounts of Cleco and its majority-owned subsidiaries after elimination of intercompany accounts and transactions.
Basis of Accounting, Policy	Basis of Presentation The condensed consolidated financial statements of Cleco Corporation and Cleco Power have been prepared pursuant to the rules and regulations of the SEC. Accordingly, certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted; however, Cleco believes that the disclosures are adequate to make the information presented not misleading. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The unaudited financial information included in the condensed consolidated financial statements of Cleco Corporation and Cleco Power reflects all adjustments of a normal recurring nature which are, in the opinion of the management of Cleco Corporation and Cleco Power, necessary for a fair statement of the financial position and the results of operations for the interim periods. Information for interim periods is affected by seasonal variations in sales, rate changes, timing of fuel expense recovery, and other factors, and is not indicative necessarily of the results that may be expected for the full fiscal year. For more information on recent authoritative guidance and its effect on financial results, see Note 2 — “Recent Authoritative Guidance.”
Property, Plant and Equipment	Property, Plant, and Equipment Property, plant, and equipment consist primarily of regulated utility generation and energy transmission assets. Regulated assets, utilized primarily for retail operations and electric transmission and distribution, are stated at the cost of construction, which includes certain materials, labor, payroll taxes and benefits, administrative and general costs, and the estimated cost of funds used during construction. Jointly owned assets are reflected in property, plant, and equipment at Cleco Power’s share of the cost to construct or purchase the assets.
Restricted Cash	Restricted Cash and Cash Equivalents Various agreements to which Cleco is subject contain covenants that restrict its use of cash. As certain provisions under these agreements are met, cash is transferred out of related escrow accounts and becomes available for its intended purposes and/or general corporate purposes.
Fair Value Measurements and Disclosures	Fair Value Measurements and Disclosures Various accounting pronouncements require certain assets and liabilities to be measured at their fair values. Some assets and liabilities are required to be measured at their fair value each reporting period, while others are required to be measured only one time, generally the date of acquisition or debt issuance. Cleco and Cleco Power are required to disclose the fair value of certain assets and liabilities by one of three levels when required for recognition purposes under GAAP. Other financial assets and liabilities, such as long-term debt, are reported at their carrying values at their date of issuance on the condensed consolidated balance sheets with their fair values as of the balance sheet date disclosed within the three levels. For more information about fair value levels, see Note 4 — “Fair Value Accounting.”
Risk Management	Risk Management Market risk inherent in Cleco Power’s market risk-sensitive instruments and positions includes potential changes arising from changes in interest rates and the commodity market prices of power and natural gas on different energy exchanges. Cleco’s Energy Market Risk Management Policy authorizes the use of various derivative instruments, including exchange traded futures and option contracts, forward purchase and sales contracts, and swap transactions to reduce exposure to fluctuations in the price of power and natural gas. Cleco applies the authoritative guidance as it relates to derivatives and hedging to determine whether the market risk-sensitive instruments and positions are required to be marked-to-market. Generally, Cleco Power’s market risk-sensitive instruments and positions qualify for the normal-purchase, normal-sale exception to mark-to-market accounting because Cleco Power takes physical delivery and the instruments and positions are used to satisfy customer requirements. Cleco Power may enter into positions to mitigate the volatility in customer fuel costs. These positions are marked-to-market with the resulting gain or loss recorded on the balance sheet as a component of energy risk management assets or liabilities. Such gain or loss is deferred as a component of deferred fuel assets or liabilities. When these positions close, actual gains or losses will be included in the fuel adjustment clause and reflected on customers’ bills as a component of the fuel cost adjustment. Cleco Power maintains margin accounts with commodity brokers used to partially fund the acquisition of natural gas futures, options, and swap contracts. These contracts/positions are used to mitigate the risks associated with the volatility in customer fuel costs noted above. The current and long-term portions of collateral are reported as a component of energy risk management assets or liabilities and other deferred credits, respectively. Cleco and Cleco Power maintain a master netting agreement policy and monitor credit risk exposure through review of counterparty credit quality, counterparty credit exposure, and counterparty concentration levels. Cleco manages these risks by establishing appropriate credit and concentration limits on transactions with counterparties and by requiring contractual guarantees, cash deposits, or letters of credit from counterparties or their affiliates, as deemed necessary. Cleco Power has agreements in place with various counterparties that authorize the netting of financial buys and sells and contract payments to mitigate credit risk for transactions entered into for risk management purposes. Cleco has entered into various contracts to mitigate the volatility in interest rate risk. These contracts include, but are not limited to, interest rate swaps and treasury rate locks. For these contracts in which Cleco is hedging the variability of cash flows related to forecasted transactions that qualify as cash flow hedges, the changes in the fair value of such derivative instruments are reported in other comprehensive income. To qualify for hedge accounting, the relationship between the hedging instrument and the hedged item must be documented to include the risk management objective and strategy, and, at inception and on an ongoing basis, the effectiveness of the hedge in offsetting the changes in the cash flows of the item being hedged. Gains or losses accumulated in other comprehensive income are reclassified as earnings in the periods in which earnings are affected by the variability of the cash flows of the hedged item. The ineffective portions of hedges will be recognized in current period earnings unless management determines that it is probable that the costs will be recovered through the rate-making process. If management determines that it is probable that the costs will be recovered, then they will be recognized as a regulatory asset or liability and amortized to earnings over the life of the related debt. For those contracts in which Cleco is hedging the variability of cash flows related to forecasted transactions that do not qualify as cash flow hedges, the changes in the fair value of such derivative instruments will be recognized in current period earnings unless management determines that it is probable that the costs will be recovered through the rate-making process. If management determines that it is probable that the costs will be recovered, then such costs will be recognized as a regulatory asset or liability and amortized to earnings over the life of the related debt. For more information on the interest rate risk contracts, see Note 4 — “Fair Value Accounting — Interest Rate Derivatives.”
Reclassification	Reclassifications Certain reclassifications have been made to the 2011 financial statements to conform them to the presentation used in the 2012 financial statements. These reclassifications had no effect on Cleco Corporation’s net income applicable to common stock or total common shareholders’ equity or Cleco Power’s net income or total member’s equity.
Earnings Per Share	Stock option grants are excluded from the computation of diluted earnings per share if the exercise price is higher than the average market price.
Stock-Based Compensation	Stock-Based Compensation At September 30, 2012, Cleco had two stock-based compensation plans, the ESPP and the LTICP. Substantially all employees, excluding officers and general managers, may choose to participate in the ESPP and purchase a limited amount of common stock at a discount through a stock option agreement. Options or restricted shares of stock, known as non-vested stock as defined by the authoritative guidance on stock-based compensation, common stock equivalents, and stock appreciation rights may be granted to certain officers, key employees, or directors of Cleco Corporation and its subsidiaries pursuant to the LTICP.