Intangible Assets and Liabilities - Schedule of Amortization of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
LTSA
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible liabilities	$ 871	$ 871	$ 2,613	$ 2,613
Power supply agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible liabilities	389	882	1,989	2,646
Cleco Katrina/Rita right to bill and collect storm recovery charges
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	0	0	0	517
Cleco Katrina/Rita right to bill and collect storm recovery charges | CLECO POWER
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	0	0	0	517
Trade name
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	3,770	64	3,897	191
Power supply agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 6,400	$ 6,400	$ 19,200	$ 19,200