Regulatory Assets and Liabilities - Schedule of Regulatory Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Regulatory Assets [Line Items]
Total regulatory assets, net	$ 300,087	$ 311,525
Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory assets	125,105	127,977
Postretirement costs
Regulatory Assets [Line Items]
Regulatory assets	16,902	17,399
Financing costs
Regulatory Assets [Line Items]
Regulatory assets	7,849	7,935
Debt issuance costs
Regulatory Assets [Line Items]
Regulatory assets	5,504	5,665
CLECO POWER
Regulatory Assets [Line Items]
Total regulatory assets, net	144,727	152,549
CLECO POWER | Interest costs
Regulatory Assets [Line Items]
Regulatory assets	3,896	3,958
CLECO POWER | AROs
Regulatory Assets [Line Items]
Regulatory assets	3,815	3,668
CLECO POWER | Postretirement costs
Regulatory Assets [Line Items]
Regulatory assets	147,889	151,543
CLECO POWER | Tree trimming costs
Regulatory Assets [Line Items]
Regulatory assets	11,384	11,341
CLECO POWER | Training costs
Regulatory Assets [Line Items]
Regulatory assets	6,202	6,241
CLECO POWER | Surcredits, net
Regulatory Assets [Line Items]
Regulatory assets	72	145
CLECO POWER | AMI deferred revenue requirement
Regulatory Assets [Line Items]
Regulatory assets	3,000	3,136
CLECO POWER | Emergency declarations
Regulatory Assets [Line Items]
Regulatory assets	948	1,349
CLECO POWER | Production operations and maintenance expenses
Regulatory Assets [Line Items]
Regulatory assets	6,756	7,985
CLECO POWER | AFUDC equity gross-up
Regulatory Assets [Line Items]
Regulatory assets	71,992	72,766
CLECO POWER | Acquisition/ transaction costs
Regulatory Assets [Line Items]
Regulatory assets	2,098	2,124
CLECO POWER | Acquisition/ transaction costs | Coughlin transaction costs
Regulatory Assets [Line Items]
Regulatory assets	899	906
CLECO POWER | Financing costs
Regulatory Assets [Line Items]
Regulatory assets	7,461	7,554
CLECO POWER | Non-service cost of postretirement benefits
Regulatory Assets [Line Items]
Regulatory assets	7,551	6,739
CLECO POWER | Energy efficiency
Regulatory Assets [Line Items]
Regulatory assets	2,820	2,820
CLECO POWER | Accumulated deferred fuel
Regulatory Assets [Line Items]
Regulatory assets	$ 16,353	$ 22,910