Fair Value Accounting - Fair Value of Derivative Instruments as Recorded in Condensed Consolidated Balance Sheets (Details) - DERIVATIVES NOT DESIGNATED AS HEDGING INSTRUMENTS - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Commodity-related contracts
Commodity-related contracts, net	$ 63,335	$ 10,167
Commodity-related contracts | CLECO POWER
Commodity-related contracts
Commodity-related contracts, net	5,990	3,216
Commodity-related contracts | Energy risk management assets
Commodity-related contracts
Derivative asset	8,662	4,805
Commodity-related contracts | Energy risk management assets | CLECO POWER
Commodity-related contracts
Derivative asset	6,867	4,337
Commodity-related contracts | Energy risk management liabilities
Commodity-related contracts
Derivative liability	(1,161)	(1,625)
Commodity-related contracts | Energy risk management liabilities | CLECO POWER
Commodity-related contracts
Derivative liability	(877)	(1,121)
Other commodity derivatives | Energy risk management assets
Commodity-related contracts
Derivative asset	30,063	8,276
Other commodity derivatives | Energy risk management liabilities
Commodity-related contracts
Derivative liability	0	(828)
Other commodity derivatives | Other deferred charges
Commodity-related contracts
Derivative asset	25,771	323
Other commodity derivatives | Other deferred credits
Commodity-related contracts
Derivative liability	$ 0	$ (784)