Regulation and Rates - Provision for Rate Refund (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jul. 31, 2019
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	$ 9,444	$ 38,903
Cleco Power
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	8,630	38,241	$ 79,200
TCJA | Cleco Power
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	2,057	28,700
FERC audit | Cleco Power
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	1,912	3,482
FRP | Cleco Power
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	1,786	1,851
Cleco Katrina/Rita storm recovery charges | Cleco Power
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	1,617	0
Site-specific industrial customer | Cleco Power
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	710	844
Transmission ROE | Cleco Power
Public Utilities, General Disclosures [Line Items]
Provision for rate refund	$ 595	$ 1,020