Fair Value Accounting and Financial Instruments - Significant Unobservable Inputs Used in Developing Fair Value of Level 3 Positions (Details) - Measured on a Recurring Basis - Level 3 $ in Thousands	Sep. 30, 2021 USD ($) $ / MW	Dec. 31, 2020 USD ($) $ / MW
FAIR VALUE
ASSETS | $	$ 9,338	$ 4,805
LIABILITIES | $	1,589	1,625
CLECO POWER
FAIR VALUE
ASSETS | $	6,028	4,337
LIABILITIES | $	$ 1,330	$ 1,121
Minimum
FAIR VALUE
FORWARD PRICE RANGE (usd per mwh) | $ / MW	(8.18)	(3.49)
Minimum | CLECO POWER
FAIR VALUE
FORWARD PRICE RANGE (usd per mwh) | $ / MW	(3.26)	(3.34)
Maximum
FAIR VALUE
FORWARD PRICE RANGE (usd per mwh) | $ / MW	9.16	4.36
Maximum | CLECO POWER
FAIR VALUE
FORWARD PRICE RANGE (usd per mwh) | $ / MW	9.16	4.36