Public Utilities, Number Of Complaints

No definition available.

Name:	cnl_PublicUtilitiesNumberOfComplaints
Namespace Prefix:	cnl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	cnl_PublicUtilitiesReturnOnEquityForCustomerRefundLowRange
Namespace Prefix:	cnl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of retail earnings to be returned to retail customers as ordered by the regulatory agency when the return on equity falls within a certain range.

+ References

No definition available.

+ Details

Name:	cnl_PublicUtilitiesReturnonEquityPercentageofretailearningsduetocustomerswithinrange
Namespace Prefix:	cnl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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.

+ References

No definition available.

+ Details

Name:	cnl_PublicUtilitiesReturnonequityforcustomerrefundhighrange
Namespace Prefix:	cnl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Tax Cuts And Jobs Act Of 2017, Bill Credit

+ References

No definition available.

+ Details

Name:	cnl_TaxCutsAndJobsActOf2017BillCredit
Namespace Prefix:	cnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Tax Cuts And Jobs Act Of 2017, Bill Credit, Change In Tax Rate

+ References

No definition available.

+ Details

Name:	cnl_TaxCutsAndJobsActOf2017BillCreditChangeInTaxRate
Namespace Prefix:	cnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Tax Cuts And Jobs Act Of 2017, Bill Credit, Unprotected Excess ADIT

+ References

No definition available.

+ Details

Name:	cnl_TaxCutsAndJobsActOf2017BillCreditUnprotectedExcessADIT
Namespace Prefix:	cnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Tax Cuts And Jobs Act Of 2017, Customer Refund Liability, Current

+ References

No definition available.

+ Details

Name:	cnl_TaxCutsAndJobsActOf2017CustomerRefundLiabilityCurrent
Namespace Prefix:	cnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Percentage of public utility's approved return on equity.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 405
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6500807&loc=d3e48068-110394

+ Details

Name:	us-gaap_RegulatoryLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amortization period for the recovery of regulatory liability, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_RegulatoryLiabilityAmortizationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period.

+ References

+ Details

Name:	us-gaap_RegulatoryLiabilityCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cnl_CostOfServiceSavingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cnl_ClecoKatrinaRitaStormRecoveryChargesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=cnl_FederalEnergyRegulatoryCommissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=cnl_ClecoPowerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cnl_CostOfServiceSavingsRefundExpectedSeptember2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cnl_CostOfServiceSavingsRefundExpectedSeptember2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryAgencyAxis=cnl_LouisianaPublicServiceCommissionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsAxis=cnl_MergerCommitmentscostsavingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=cnl_FRPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RegulatoryLiabilityAxis=cnl_ExcessADITMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilitiesRegulatoryProceedingAxis=cnl_TransmissionreturnonequityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Regulation and Rates - Narrative (Details) $ in Thousands			6 Months Ended
Regulation and Rates - Narrative (Details) $ in Thousands	Jul. 01, 2021	Jun. 16, 2021 USD ($)	Jun. 30, 2021 USD ($) complaint	Dec. 31, 2020 USD ($)	Nov. 13, 2020 USD ($)	Jul. 31, 2019 USD ($)
Regulation and Rates [Line Items]
Refund due to customers			$ 7,251	$ 9,444
Current regulatory liabilities			44,862	23,509
FRP
Regulation and Rates [Line Items]
Refund due to customers			2,392	1,786
Cleco Katrina/Rita storm recovery charges
Regulation and Rates [Line Items]
Refund due to customers			$ 1,610	1,617
FERC
Regulation and Rates [Line Items]
Number of complaints filed \| complaint			2
CLECO POWER
Regulation and Rates [Line Items]
Refund due to customers			$ 7,251	8,630		$ 79,200
Regulatory liabilities			153,770	180,565
Current regulatory liabilities			44,862	23,509
CLECO POWER \| FRP
Regulation and Rates [Line Items]
Refund due to customers			2,392	1,786
CLECO POWER \| FRP, expected to refund September 2021
Regulation and Rates [Line Items]
Refund due to customers			1,200
CLECO POWER \| FRP, expected to refund September 2022
Regulation and Rates [Line Items]
Refund due to customers			1,200
CLECO POWER \| Cleco Katrina/Rita storm recovery charges
Regulation and Rates [Line Items]
Refund due to customers			1,610	$ 1,617
CLECO POWER \| LPSC
Regulation and Rates [Line Items]
TCJA, bill credit per month					$ 7,000
Bill credit related to unprotected excess ADIT					4,400
Bill credit per month related to change in federal statutory tax rate					$ 2,600
Estimated refund for the tax-related benefits from the TCJA			2,100
CLECO POWER \| LPSC \| Merger Commitments, cost savings
Regulation and Rates [Line Items]
Regulatory liabilities			$ 4,300
CLECO POWER \| LPSC \| FRP
Regulation and Rates [Line Items]
Target ROE allowed by FRP			10.00%
Percentage of retail earnings within range to be returned to customers			60.00%
ROE for customer credit, low range			10.90%
ROE for customer credit, high range			11.75%
CLECO POWER \| LPSC \| FRP \| Subsequent event
Regulation and Rates [Line Items]
Target ROE allowed by FRP	9.50%
Percentage of retail earnings within range to be returned to customers	60.00%
ROE for customer credit, low range	10.00%
ROE for customer credit, high range	10.50%
CLECO POWER \| LPSC \| FRP \| Maximum
Regulation and Rates [Line Items]
Target ROE allowed by FRP			10.90%
CLECO POWER \| LPSC \| FRP \| Maximum \| Subsequent event
Regulation and Rates [Line Items]
Target ROE allowed by FRP	10.00%
CLECO POWER \| LPSC \| Excess ADIT
Regulation and Rates [Line Items]
Bill credit related to unprotected excess ADIT		$ 2,500
Regulatory liability, amortization period		3 years
Regulatory liabilities			$ 324,600
Current regulatory liabilities			39,500
CLECO POWER \| FERC \| Transmission return on equity
Regulation and Rates [Line Items]
Refund due to customers			$ 300