Regulatory Assets and Liabilities, Summary of Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Total regulatory assets, net	$ 720,017	$ 739,683
Cleco Power [Member]
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	271,925	285,737
Total regulatory assets, net	533,413	543,973
Cleco Power [Member] | Regulatory assets – deferred taxes, net
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	240,431	237,449
Cleco Power [Member] | Mining costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	4,461	6,372
Cleco Power [Member] | Interest costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	4,590	4,860
Cleco Power [Member] | AROs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,590	2,096
Cleco Power [Member] | Postretirement costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	137,815	145,268
Cleco Power [Member] | Tree trimming costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	6,801	5,549
Cleco Power [Member] | Training costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	6,591	6,708
Cleco Power [Member] | Surcredits, net
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	3,084	5,876
Cleco Power [Member] | AMI deferred revenue requirement
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	4,363	4,772
Cleco Power [Member] | Emergency declarations
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	3,976	0
Cleco Power [Member] | Production operations and maintenance expenses
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	9,656	13,999
Cleco Power [Member] | AFUDC equity gross-up
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	70,046	70,423
Cleco Power [Member] | Acquisition/ transaction costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,362	2,442
Cleco Power [Member] | Acquisition/ transaction costs | Coughlin transaction costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	976	999
Cleco Power [Member] | Financing costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	8,385	8,663
Cleco Power [Member] | Biomass costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	0	18
Cleco Power [Member] | MISO integration costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	702	1,404
Cleco Power [Member] | Corporate franchise tax
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	968	1,308
Cleco Power [Member] | MATS costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	3,846	4,270
Cleco Power [Member] | Other
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	713	710
Cleco Power [Member] | Accumulated deferred fuel
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	21,057	20,787
Cleco Holdings [Member] | Postretirement costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	21,872	23,362
Cleco Holdings [Member] | Financing costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	8,708	8,966
Cleco Holdings [Member] | Fair value of long-term debt
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	149,256	155,776
Cleco Holdings [Member] | Debt issuance costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	$ 6,768	$ 7,606