Regulatory Assets and Liabilities, Summary of Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Total regulatory assets, net	$ 331,803	$ 330,582
Cleco Power
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	266,239	273,220
Total regulatory assets, net	150,794	146,774
Cleco Power | Mining costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	3,186	3,823
Cleco Power | Interest costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	4,410	4,499
Cleco Power | AROs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,689	2,762
Cleco Power | Postretirement costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	139,822	142,764
Cleco Power | Tree trimming costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	7,579	7,193
Cleco Power | Training costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	6,513	6,552
Cleco Power | Surcredits, net
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	1,195	2,173
Cleco Power | AMI deferred revenue requirement
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	4,090	4,227
Cleco Power | Emergency declarations
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	4,004	4,131
Cleco Power | Production operations and maintenance expenses
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	7,226	8,625
Cleco Power | AFUDC equity gross-up
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	71,245	71,205
Cleco Power | Acquisition/ transaction costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,310	2,336
Cleco Power | Acquisition/ transaction costs | Coughlin transaction costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	961	968
Cleco Power | Financing costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	8,201	8,293
Cleco Power | MISO integration costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	234	468
Cleco Power | Corporate franchise tax, net
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	0	153
Cleco Power | MATS costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	1,282	2,564
Cleco Power | Non-service cost of postretirement benefits
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	1,037	0
Cleco Power | Other
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	255	484
Cleco Power | Accumulated deferred fuel
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	23,053	13,980
Cleco Holdings | Postretirement costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	20,878	21,375
Cleco Holdings | Financing costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	8,536	8,623
Cleco Holdings | Fair value of long-term debt
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	145,033	147,145
Cleco Holdings | Debt issuance costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	6,562	6,665
Regulatory liabilities - deferred taxes, net | Cleco Power
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory liabilities	(138,329)	(140,426)
Corporate franchise tax, net | Cleco Power
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory liabilities	$ (169)	$ 0