Fair Value Accounting - Significant Unobservable Inputs Used in Developing Fair Value of Level 3 Positions (Details) $ in Thousands	Dec. 31, 2020 USD ($) $ / MW	Dec. 31, 2019 USD ($) $ / MW
MINIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Forward price range (usd per MWh) | $ / MW	(3.49)	(2.57)
MAXIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Forward price range (usd per MWh) | $ / MW	4.36	2.86
Measured On A Recurring Basis | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets | $	$ 4,805	$ 6,822
Liabilities | $	$ 1,625	$ 1,044
CLECO POWER | MINIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Forward price range (usd per MWh) | $ / MW	(3.34)	(2.04)
CLECO POWER | MAXIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Forward price range (usd per MWh) | $ / MW	4.36	2.86
CLECO POWER | Measured On A Recurring Basis | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets | $	$ 4,337	$ 6,311
Liabilities | $	$ 1,121	$ 586