Intangible Assets, Intangible Liabilities, and Goodwill - Schedule of Amortization of Intangible Assets and Liabilities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Impairments for intangibles	$ 0	$ 0	$ 0
Power supply agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible liabilities	3,528,000	3,194,000	0
LTSA
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible liabilities	3,484,000	3,234,000	0
Cleco Katrina/Rita right to bill and collect storm recover charges
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	517,000	20,576,000	20,608,000
Cleco Katrina/Rita right to bill and collect storm recover charges | Cleco Power
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	517,000	20,576,000	20,608,000
Trade name
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	255,000	255,000	255,000
Power supply agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 25,600,000	$ 24,273,000	$ 9,680,000