Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation, Policy	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 Presentation, Policy	Cleco Holdings accounted for the merger transaction by applying the acquisition method of accounting. The objective of the acquisition method is to establish a new accounting basis for the acquiree, Cleco Holdings and its subsidiaries, and requires the acquirer, Cleco Group, to recognize and measure the acquiree’s assets and liabilities at fair value as of the acquisition date. Cleco Power’s assets and liabilities were recorded at historical cost since Cleco did not elect pushdown accounting at the Cleco Power level. The financial statements and accompanying footnotes for Cleco have been segregated to present pre-merger activity as the “Predecessor” and post-merger activity as the “Successor.” The predecessor period is not comparable to the successor period.
Restricted Cash and Cash Equivalents, Policy	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. Cleco Katrina/Rita has the right to bill and collect storm restoration costs from Cleco Power’s customers. As cash is collected, it is restricted for payment of administration fees, interest, and principal on storm recovery bonds.
Fair Value Measurements and Disclosures, Policy	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 disclose the fair value of certain assets and liabilities by one of three levels when required for recognition purposes. Cleco utilizes different valuation techniques for fair value calculations. In order to measure the fair value for Level 1 assets and liabilities, Cleco obtains the closing price from published indices in active markets for the various instruments and multiplies this price by the appropriate number of instruments held. Level 2 fair values are determined by obtaining the closing price of similar assets and liabilities from published indices in active markets and then discounting the price to the current period using a U.S. Treasury published interest rate as a proxy for a risk-free rate of return. Cleco has consistently applied the Level 2 fair value technique from fiscal period to fiscal period. Level 3 fair values occur in situations in which there is little, if any, market activity for the asset or liability at the measurement date and therefore RTO auction prices are used. Significant increases or decreases in any of those inputs in isolation would result in a significantly different fair value measurement. The assets and liabilities reported at fair value are grouped into classes based on the underlying nature and risks associated with the individual asset or liability.
Risk Management, Policy	Cleco Power purchases the majority of its FTRs in annual auctions facilitated by MISO during the second quarter of each year and may also purchase additional FTRs in monthly auctions facilitated by MISO. FTRs are derivative instruments which represent economic hedges of future congestion charges that will be incurred in serving Cleco Power’s customer load. FTRs are not designated as hedging instruments for accounting purposes. Cleco Power initially records FTRs at their estimated fair value and subsequently adjusts the carrying value to their estimated fair value at the end of each accounting period based on the most recent MISO FTR auction prices. Unrealized gains or losses on FTRs held by Cleco Power are included in Accumulated deferred fuel on Cleco Power’s Condensed Consolidated Balance Sheets. Realized gains or losses on settled FTRs are recorded in Fuel used for electric generation on Cleco Power’s Condensed Consolidated Statements of Income. Cleco and Cleco Power maintain a master netting agreement policy and monitor credit risk exposure through review of counterparty credit quality, aggregate counterparty credit exposure, and aggregate counterparty concentration levels. Cleco manages these risks by establishing appropriate credit and concentration limits on transactions with counterparties and 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 and Cleco Power may enter into contracts to mitigate the volatility in interest rate risk. These contracts include, but are not limited to, interest rate swaps and treasury rate locks. Market risk inherent in Cleco’s market risk-sensitive instruments and positions includes potential changes in value arising from changes in interest rates and the commodity market prices of power, FTRs, and natural gas in the industry 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, FTRs, and natural gas. Cleco evaluates derivatives and hedging activities to determine whether the market risk-sensitive instruments and positions are required to be marked-to-market. Cleco Power may also enter into risk mitigating positions that would not meet the requirements of a normal-purchase, normal-sale transaction in order to attempt to mitigate the volatility in customer fuel costs. These positions would be marked-to-market with the resulting gain or loss recorded on Cleco and Cleco Power’s Condensed Consolidated Balance Sheets as a component of energy risk management assets or liabilities. Such gain or loss would be deferred as a component of deferred fuel assets or liabilities in accordance with regulatory policy. When these positions close, actual gains or losses would be included in the FAC and reflected on customers’ bills as a component of the fuel charge. In June 2015, the LPSC approved a long-term natural gas hedging pilot program that requires Cleco Power to establish a proposal for a program that will be designed to provide gas price stability for a minimum of five years. This proposal is currently scheduled to be submitted to the LPSC by June 30, 2017
Stock-Based Compensation, Policy	Prior to the completion of the Merger, Cleco had two stock-based compensation plans: the ESPP and the LTIP. As a result of the completion of the Merger, the ESPP and the LTIP were terminated. Pursuant to the terms of the LTIP, certain officers, key employees, and directors of Cleco were eligible to be granted stock options, restricted stock, also known as non-vested stock, common stock equivalents, and stock appreciation rights. As a result of the Merger on April 13, 2016, all unvested shares outstanding under the LTIP that were granted prior to January 1, 2015, vested at target and were paid out in cash to plan participants. Unvested shares that were granted during 2015 were prorated to the target amount and paid out in cash to plan participants in accordance with the terms of the Merger Agreement.
Business Combinations, Policy	Most of the carrying values of Cleco’s assets and liabilities were determined to be stated at fair value at the Merger date, considering that most of these assets are subject to regulation by the LPSC and FERC. Under such regulation, rates charged to customers are established by a regulator to provide for recovery of costs and a fair return on rate base and are generally measured at historical cost. As such, a market participant would not expect to recover any more or less than the carrying value of the assets. Prior to the Merger, the Coughlin step-up value was not recorded on Cleco’s Condensed Consolidated Balance Sheet due to the accounting treatment for the transfer of that asset in March 2014. However, the recovery of the step-up value of the Coughlin asset was approved by the LPSC for recovery in base rates, including a return on rate base. On the date of the Merger, the step-up value for the Coughlin asset was recognized on Cleco’s Condensed Consolidated Balance Sheet since Cleco Power is able to earn a return on and recover these costs from its customers. The beginning balance of fixed depreciable assets was shown net at the date of the Merger, as no accumulated depreciation existed on the date of the Merger. The excess of the purchase price over the estimated fair value of assets acquired and the liabilities assumed was $1.49 billion, which was recognized as goodwill by Cleco Holdings at the Merger date. The goodwill represents the potential long-term return of Cleco to its member. Management has assigned goodwill to Cleco’s reportable segment, Cleco Power. A fair value adjustment was recorded on Cleco’s Condensed Consolidated Balance Sheet to reflect the valuation of the Cleco trade name. This adjustment is included in Intangible assets on Cleco’s Condensed Consolidated Balance Sheet. The valuation of the trade name was estimated by applying the relief-from-royalty method under the income approach. This valuation method is based on the premise that, in lieu of ownership of the asset, a company would be willing to pay a royalty to a third-party for the use of that asset. The owner of the asset is spared this cost, and the value of the asset is estimated by the cost savings. The projected revenue attributed to the trade name was based on projections of the value of Cleco’s wholesale contracts. The trade name is being amortized over 20 years. The amortization of the Cleco trade name is included in Depreciation and amortization on Cleco’s Condensed Consolidated Statement of Income. On the date of the Merger, fair value adjustments were recorded on Cleco’s Condensed Consolidated Balance Sheet for the difference between the contract price and the market price of long-term wholesale power supply agreements. These adjustments are classified as Intangible assets on Cleco’s Condensed Consolidated Balance Sheet. The valuation of the power supply agreements was estimated using the income approach. The income approach is based upon discounted projected future cash flows associated with the underlying contracts. The intangible assets for the power supply agreements are being amortized over the remaining term of each applicable contract. The amortization of the power supply agreements is included in Electric operations on Cleco’s Condensed Consolidated Statement of Income. The net increase in deferred tax liabilities on Cleco’s Condensed Consolidated Balance Sheet represents the differences between the assigned fair values of assets acquired and their related income tax basis, net of a deferred tax asset representing the net operating loss carryforward that will be utilized in future periods. As the underlying asset assigned fair values are amortized, the related deferred tax liabilities will be included in income tax expense. Goodwill is not deductible for income tax purposes; therefore, no deferred income tax assets or liabilities were recognized for goodwill. Other fair value adjustments were recorded for long-term debt, postretirement benefit remeasurements and deferred losses, and interest rate derivative settlement gains/losses. These fair value adjustments are subject to rate regulation, but do not earn a return. In these instances, a corresponding regulatory asset was established, as the underlying utility asset or liability amounts are recoverable from or refundable to customers at historical cost through the rate setting process. These regulatory assets established to offset fair value adjustments are amortized in amounts and over time frames consistent with the realization or settlement of the fair value adjustments. In November and December 2016, Cleco Power redeemed $60.0 million and $250.0 million in long-term debt, respectively. As a result, the fair value adjustments for the redeemed long-term debt and the related unamortized debt issuance cost of $19.8 million on Cleco’s Consolidated Balance Sheet were derecognized. The offset was to the respective regulatory assets. The valuations performed in the second quarter of 2016 to estimate the fair value of assets acquired and liabilities assumed were considered preliminary as a result of the short time period between the closing of the Merger and the end of the second quarter of 2016. During the third quarter of 2016, valuations were performed for the valuation and assessment of the postretirement benefit plans as of April 13, 2016, and the economic useful life of the Cleco trade name. Cleco completed its evaluation and determination of the fair value of certain assets and liabilities acquired as of December 31, 2016. There were no adjustments to those amounts during the first quarter of 2017. While management believes the positions reflected on the income tax returns are reasonable, the returns have not been audited by the applicable taxing authorities. As a result of the Merger, Cleco implemented acquisition accounting, which eliminated AOCI at the Cleco consolidated level on the date of the Merger. Cleco will continue to recover expenses related to certain postretirement costs; therefore, Cleco recognized a regulatory asset based on its determination that these costs can continue to be collected from customers. These costs will be amortized to Other operations expense over the average remaining service period of participating employees. Cleco will also continue to recover financing costs associated with the settlement of two treasury rate locks and a forward starting swap contract that were previously recognized in AOCI. Additionally, as a result of the Merger, a regulatory asset was recorded for debt issuance costs that were eliminated at Cleco and a regulatory asset was recorded for the difference between the carrying value and the fair value of long-term debt. These regulatory assets will be amortized over the terms of the related debt issuances.
Pushdown Accounting, Policy	Pushdown accounting was applied to Cleco, and accordingly, the Cleco consolidated assets acquired and liabilities assumed were recorded on April 13, 2016, at their fair values
Recent Authoritative Guidance, Policy	In May 2014, FASB amended the accounting guidance for revenue recognition. The amended guidance affects entities that enter into contracts for the transfer of non-financial assets unless those contracts are within the scope of other standards. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Under the new guidance, an entity must identify the performance obligations in a contract and the transaction price, and allocate the price to specific performance obligations to recognize the revenue when the obligation is completed. The amendments in this update also require extensive disclosure of sufficient information to allow users to understand the nature, amount, timing, and uncertainty of revenue and cash flow arising from contracts. Additional disclosure requirements include disaggregated revenue, reconciliation of contract balances, the entity’s performance obligations, significant judgments used, costs to obtain or fulfill a contract and the use of practical expedients. The standard will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Reporting entities have the option of using either a full retrospective or a modified retrospective approach. Under the full retrospective approach, companies will apply rules to contracts in all reporting periods presented, subject to certain allowable exceptions. Under the modified retrospective approach, companies will apply the rules to all contracts existing as of January 1, 2018, recognizing in beginning retained earnings an adjustment for the cumulative effect of the change and providing additional disclosures comparing results to previous rules. Cleco intends to implement the amended guidance in January 2018 using the modified retrospective approach. Upon initial evaluation, key changes in the standard that management is assessing for potential areas of impact include accounting for contract modifications, contracts with pricing provisions that may require it to recognize revenue at prices other than the contract price (e.g., straight-line or estimated future market prices), and the ability to recognize revenue in situations where collectability is in question. Management will continue to evaluate the impact of this guidance, including additional clarifying amendments issued following the date of initial issuance. The amended guidance could have a material impact on the results of operations, financial condition, or cash flows of the Registrants. In February 2016, FASB amended the guidance to account for leases. This guidance is intended to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The adoption of this guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those years. Early adoption is permitted. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes practical expedients that may be elected by entities. Management will continue to evaluate the impact of this guidance. The amended guidance could have a material impact on the results of operations, financial condition, or cash flows of the Registrants. In November 2016, FASB amended guidance for certain cash flow issues. The amended guidance requires that a statement of cash flow explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash. Therefore, amounts generally described as restricted cash and cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The adoption of this guidance is effective for fiscal years beginning after December 15, 2017, including interim reporting periods within those fiscal years. Early adoption is permitted. This amendment should be applied using a retrospective transition method to each period presented. This guidance will impact the presentation of the cash flow statement, but will not have an impact on the results of operations or financial condition of the Registrants. In January 2017, FASB amended the accounting guidance to simplify the measurement of a goodwill impairment loss. The amended guidance eliminates step two of the goodwill impairment test, which requires a hypothetical purchase price allocation to measure goodwill impairment. Under the new guidance, a goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The adoption of this guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those years. Early adoption is permitted. Management is evaluating the impact that the adoption of this guidance will have on the results of operations, financial condition, or cash flows of the Registrants. In March 2017, FASB amended guidance related to defined benefit pension and other postretirement benefit plans. The new amendment requires an entity to present service cost in the same line item as other current employee compensation costs and to present the remaining components of net benefit cost in a separate line item outside of operating items. The amendment also allows only the service cost component of net benefit cost to be eligible for capitalization. The adoption of this guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those years. This amendment should be applied retrospectively for the presentation of the service cost in the income statement while the capitalization of the service cost should be applied prospectively. Management is currently evaluating the impact of this standard, including coordinating with its industry group as well as its advisors. The adoption of this guidance could have a material impact on the results of operations, financial condition, or cash flows of the Registrants.
Regulatory Assets and Liabilities, Policy	Cleco capitalizes or defers certain costs for recovery from customers and recognizes a liability for amounts expected to be returned to customers based on regulatory approval and management’s ongoing assessment that it is probable these items will be recovered or refunded through the ratemaking process. Under the current regulatory environment, Cleco believes these regulatory assets will be fully recoverable; however, if in the future, as a result of regulatory changes or competition, Cleco’s ability to recover these regulatory assets would no longer be probable, then to the extent that such regulatory assets were determined not to be recoverable, Cleco would be required to write-down such assets. In addition, potential deregulation of the industry or possible future changes in the method of rate regulation of Cleco could require discontinuance of the application of the authoritative guidance on regulated operations.
Pension and Other Postretirement Plans, Policy	Cleco’s retirees and their dependents may be eligible to receive medical, dental, vision, and life insurance benefits (other benefits). Cleco recognizes the expected cost of these other benefits during the periods in which the benefits are earned. Employees hired before August 1, 2007, are covered by a non-contributory, defined benefit pension plan. Benefits under the plan reflect an employee’s years of service, age at retirement, and highest total average compensation for any consecutive five calendar years during the last ten years of employment with Cleco. Cleco’s policy is to base its contributions to the employee pension plan upon actuarial computations utilizing the projected unit credit method, subject to the IRS’s full funding limitation. Cleco’s 401(k) Plan is intended to provide active, eligible employees with voluntary, long-term savings and investment opportunities. The 401(k) Plan is a defined contribution plan and is subject to the applicable provisions of the Employee Retirement Income Security Act of 1974. In accordance with the 401(k) Plan, employer contributions can be made in the form of cash. Cash contributions are invested in proportion to the participant’s voluntary contribution investment choices. Prior to the close of the Merger on April 13, 2016, employer contributions could also be in the form of Cleco Corporation common stock. Participation in the 401(k) Plan is voluntary, and all active Cleco employees are eligible to participate. Certain Cleco officers are covered by SERP. SERP is a non-qualified, non-contributory, defined benefit pension plan. Generally, benefits under the plan reflect an employee’s years of service, age at retirement and the sum of (a) the highest base salary paid out over the last five calendar years and (b) the average of the three highest cash bonuses paid during the 60 months prior to retirement. SERP benefits are reduced by retirement benefits received from any other defined benefit pension plan, supplemental executive retirement plan, or Cleco contributions under the enhanced 401(k) Plan to the extent such contributions exceed the limits of the 401(k) Plan. Two executive officers’ SERP benefits will be capped as of December 31, 2017, with regard to final compensation; however, adjustments will continue with regard to age and tenure with Cleco. Additionally, these executive officers had their annual bonuses set at target rather than actual awards for the year 2016 and will have their annual bonuses set at target rather than actual awards for the year 2017 for the average incentive award portion of their SERP benefit calculation. A third executive officer’s SERP calculation will use a fixed salary amount for 2017 and will exclude any compensation exceeding this amount. In 2014, SERP was closed to new participants; however, with regard to current SERP participants, including former employees or their beneficiaries, all terms of SERP will continue, other than as described above. In accordance with the SERP plan document and the Merger Agreement, four executive officers received enhanced benefits, and upon termination of employment, two of these executive officers received accelerated vesting. Another executive officer received enhanced SERP benefits, net of other postretirement benefits, as part of a separation agreement. Management will review current market trends as it evaluates Cleco’s future compensation strategy. Cleco does not fund the SERP liability, but instead pays for current benefits out of the general funds available. Cleco Power has formed a rabbi trust designated as the beneficiary for life insurance policies issued on SERP participants. Market conditions could have a significant impact on the cash surrender value of the life insurance policies. Proceeds from the life insurance policies are expected to be used to pay the SERP participants’ death benefits, as well as future SERP payments. However, because SERP is a non-qualified plan, the assets of the trust could be used to satisfy general creditors of Cleco Power in the event of insolvency. All SERP benefits are paid out of the general cash available of the respective companies that employed the officer. Cleco Power is considered the plan sponsor and Support Group is considered the plan administrator.
Income Tax, Policy	Cleco classifies income tax penalties as a component of other expense. Cleco classifies all interest related to uncertain tax positions as a component of interest payable and interest expense. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized.
Segment Reporting, Policy	The financial results of Cleco’s segment are presented on an accrual basis.
Equity Method Investments, Policy	Cleco and Cleco Power apply the equity method of accounting to report the investment in Oxbow in the consolidated financial statements. Under the equity method, the assets and liabilities of this entity are reported as Equity investment in investee on Cleco and Cleco Power’s Condensed Consolidated Balance Sheets. The revenue and expenses (excluding income taxes) of this entity are netted and reported as equity income or loss from investees on Cleco and Cleco Power’s Condensed Consolidated Statements of Income.
Variable Interest Entity, Policy	Oxbow is owned 50% by Cleco Power and 50% by SWEPCO. Cleco Power is not the primary beneficiary because it shares the power to control Oxbow’s significant activities with SWEPCO.