Regulation and Rates - Provision for Rate Refund (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jul. 31, 2019
Regulation and Rates [Line Items]
Provision for rate refund	$ 7,251	$ 9,444
FRP
Regulation and Rates [Line Items]
Provision for rate refund	2,392	1,786
TCJA
Regulation and Rates [Line Items]
Provision for rate refund	2,057	2,057
Cleco Katrina/Rita storm recovery charges
Regulation and Rates [Line Items]
Provision for rate refund	1,610	1,617
Site-specific industrial customer
Regulation and Rates [Line Items]
Provision for rate refund	990	710
Transmission ROE
Regulation and Rates [Line Items]
Provision for rate refund	250	595
FERC audit
Regulation and Rates [Line Items]
Provision for rate refund	0	1,912
CLECO POWER
Regulation and Rates [Line Items]
Provision for rate refund	7,251	8,630	$ 79,200
CLECO POWER | FRP
Regulation and Rates [Line Items]
Provision for rate refund	2,392	1,786
CLECO POWER | TCJA
Regulation and Rates [Line Items]
Provision for rate refund	2,057	2,057
CLECO POWER | Cleco Katrina/Rita storm recovery charges
Regulation and Rates [Line Items]
Provision for rate refund	1,610	1,617
CLECO POWER | Site-specific industrial customer
Regulation and Rates [Line Items]
Provision for rate refund	990	710
CLECO POWER | Transmission ROE
Regulation and Rates [Line Items]
Provision for rate refund	250	595
CLECO POWER | FERC audit
Regulation and Rates [Line Items]
Provision for rate refund	$ 0	$ 1,912