Fair Value Accounting - Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) - Price Risk Derivative - Derivatives Not Designated as Hedging Instrument - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
FTRs:
Commodity-related contracts, net	$ 22,887	$ 7,044
Energy risk management assets
FTRs:
Energy risk management assets	23,355	7,396
Energy risk management liabilities
FTRs:
Energy risk management liabilities	468	352
CLECO POWER
FTRs:
Commodity-related contracts, net	22,887	7,044
CLECO POWER | Energy risk management assets
FTRs:
Energy risk management assets	23,355	7,396
CLECO POWER | Energy risk management liabilities
FTRs:
Energy risk management liabilities	$ 468	$ 352