Amount of transfers of assets and liabilities measured on a recurring basis of fair value hierarchy Levels.

No definition available.

Name:	cnl_FairValueAssetsandLiabilitiesTransfersbetweenLevelsAmount
Namespace Prefix:	cnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Deferred Fuel

+ References

No definition available.

+ Details

Name:	cnl_FairValueNetDerivativeAssetLiabilityMeasuredonRecurringBasisUnobservableInputsReconciliationGainLossIncludedinDeferredFuel
Namespace Prefix:	cnl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

The forward price on the price risk forward or futures contract, such as a gas futures contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeForwardPrice
Namespace Prefix:	us-gaap_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19279-110258

+ Details

Name:	us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisUnobservableInputsReconciliationPurchasesSalesIssuesSettlements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair value of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19279-110258

+ Details

Name:	us-gaap_FairValueNetDerivativeAssetLiabilityMeasuredOnRecurringBasisWithUnobservableInputs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7

+ Details

Name:	us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value of financial and nonfinancial obligations.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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

- Definition

Fair value as of the balance sheet date of price risk derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets on the balance sheet.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611

+ Details

Name:	us-gaap_PriceRiskDerivativeAssetsAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value as of the balance sheet date of price risk derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities on the balance sheet.

+ References

+ Details

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

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=cnl_RestrictedCashAndCashEquivalentsCurrentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=cnl_RestrictedCashAndCashEquivalentsNoncurrentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=us-gaap_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_PriceRiskDerivativeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Fair Value Accounting, Fair Value Measurements and Disclosures(Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) $ / MW	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) $ / MW	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) $ / MW
Asset Description
Institutional money market funds	$ 40,715		$ 40,715		$ 63,701
FTR assets	22,480		22,480		10,776
Total Assets	63,195		63,195		74,477
Liability Description
Long-term debt	1,446,931		1,446,931		1,601,816
FTR liabilities	506		506		827
Total Liabilities	1,447,437		1,447,437		1,602,643
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Transfers between fair value levels	0		0		0
Cash and Cash Equivalents [Member]
Asset Description
Institutional money market funds	16,600		16,600
Restricted Cash and Cash Equivalents, Current [Member]
Asset Description
Institutional money market funds	8,300		8,300
Restricted Cash and Cash Equivalents, Noncurrent [Member]
Asset Description
Institutional money market funds	15,800		15,800
Cleco Power [Member]
Asset Description
Institutional money market funds	38,894		38,894		58,680
FTR assets	22,480		22,480		10,776
Total Assets	61,374		61,374		69,456
Liability Description
Long-term debt	1,394,931		1,394,931		1,544,816
FTR liabilities	506		506		827
Total Liabilities	1,395,437		1,395,437		$ 1,545,643
Cleco Power [Member] \| Cash and Cash Equivalents [Member]
Asset Description
Institutional money market funds	14,800		14,800
Cleco Power [Member] \| Restricted Cash and Cash Equivalents, Current [Member]
Asset Description
Institutional money market funds	8,300		8,300
Cleco Power [Member] \| Restricted Cash and Cash Equivalents, Noncurrent [Member]
Asset Description
Institutional money market funds	15,800		15,800
FTRs [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning fair value of FTR assets (liabilities), net	1,813	$ 3,908	9,949	$ 8,638
Unrealized gains (losses)	3,780	(3,420)	2,070	(3,420)
Net purchases and settlements	16,381	42,484	9,955	37,754
Ending fair value of FTR assets (liabilities), net	$ 21,974	$ 42,972	$ 21,974	$ 42,972
FTRs [Member] \| Low [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
FTRs Forward Price Range \| $ / MW	(3.18)		(3.18)		(4.12)
FTRs [Member] \| High [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
FTRs Forward Price Range \| $ / MW	5.44		5.44		7.76
Measured On A Recurring Basis [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Asset Description
Institutional money market funds	$ 0		$ 0		$ 0
FTR assets	0		0		0
Total Assets	0		0		0
Liability Description
Long-term debt	0		0		0
FTR liabilities	0		0		0
Total Liabilities	0		0		0
Measured On A Recurring Basis [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Asset Description
Institutional money market funds	40,715		40,715		63,701
FTR assets	0		0		0
Total Assets	40,715		40,715		63,701
Liability Description
Long-term debt	1,446,931		1,446,931		1,601,816
FTR liabilities	0		0		0
Total Liabilities	1,446,931		1,446,931		1,601,816
Measured On A Recurring Basis [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Asset Description
Institutional money market funds	0		0		0
FTR assets	22,480		22,480		10,776
Total Assets	22,480		22,480		10,776
Liability Description
Long-term debt	0		0		0
FTR liabilities	506		506		827
Total Liabilities	506		506		827
Measured On A Recurring Basis [Member] \| Cleco Power [Member] \| Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Asset Description
Institutional money market funds	0		0		0
FTR assets	0		0		0
Total Assets	0		0		0
Liability Description
Long-term debt	0		0		0
FTR liabilities	0		0		0
Total Liabilities	0		0		0
Measured On A Recurring Basis [Member] \| Cleco Power [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Asset Description
Institutional money market funds	38,894		38,894		58,680
FTR assets	0		0		0
Total Assets	38,894		38,894		58,680
Liability Description
Long-term debt	1,394,931		1,394,931		1,544,816
FTR liabilities	0		0		0
Total Liabilities	1,394,931		1,394,931		1,544,816
Measured On A Recurring Basis [Member] \| Cleco Power [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Asset Description
Institutional money market funds	0		0		0
FTR assets	22,480		22,480		10,776
Total Assets	22,480		22,480		10,776
Liability Description
Long-term debt	0		0		0
FTR liabilities	506		506		827
Total Liabilities	$ 506		$ 506		$ 827