Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Total regulatory assets, net	$ 339,549	$ 330,582
CLECO POWER
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	260,998	273,220
Total regulatory assets, net	161,337	146,774
CLECO POWER | Mining costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,549	3,823
CLECO POWER | Interest costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	4,340	4,499
CLECO POWER | AROs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,824	2,762
CLECO POWER | Postretirement costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	136,644	142,764
CLECO POWER | Tree trimming costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	8,015	7,193
CLECO POWER | Training costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	6,474	6,552
CLECO POWER | Surcredits, net
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	289	2,173
CLECO POWER | AMI deferred revenue requirement
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	3,954	4,227
CLECO POWER | Emergency declarations
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	3,781	4,131
CLECO POWER | Production operations and maintenance expenses
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	5,827	8,625
CLECO POWER | AFUDC equity gross-up
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	71,295	71,205
CLECO POWER | Acquisition/ transaction costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,283	2,336
CLECO POWER | Acquisition/ transaction costs | Coughlin transaction costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	953	968
CLECO POWER | Financing costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	8,108	8,293
CLECO POWER | MISO integration costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	0	468
CLECO POWER | Corporate franchise tax, net
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	1,500	153
CLECO POWER | MATS costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	0	2,564
CLECO POWER | Non-service cost of postretirement benefits
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	2,136	0
CLECO POWER | Other
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	26	484
CLECO POWER | Accumulated deferred fuel
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	36,786	13,980
Cleco Holdings | Postretirement costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	20,381	21,375
Cleco Holdings | Financing costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	8,450	8,623
Cleco Holdings | Fair value of long-term debt
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	142,922	147,145
Cleco Holdings | Debt issuance costs
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory assets	6,459	6,665
Regulatory liabilities - deferred taxes, net | CLECO POWER
Schedule of Regulatory Assets and Liabilities, Net [Line Items]
Regulatory liabilities	$ (136,447)	$ (140,426)