Regulation and Rates - Provision for Rate Refund (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Jul. 31, 2019
Regulation and Rates [Line Items]
Provision for rate refund	$ 9,852,000	$ 38,903,000
FERC audit
Regulation and Rates [Line Items]
Provision for rate refund	2,724,000	3,482,000
TCJA tax-related benefits
Regulation and Rates [Line Items]
Provision for rate refund	2,057,000	28,700,000
Cleco Katrina/Rita storm recovery charges
Regulation and Rates [Line Items]
Provision for rate refund	1,630,000	0
Cost of service savings
Regulation and Rates [Line Items]
Provision for rate refund	1,483,000	1,851,000
Site-specific industrial customer
Regulation and Rates [Line Items]
Provision for rate refund	596,000	844,000
Change in transmission ROE
Regulation and Rates [Line Items]
Provision for rate refund	595,000	1,020,000
CLECO POWER
Regulation and Rates [Line Items]
Provision for rate refund	9,038,000	38,241,000	$ 79,200,000
CLECO POWER | FERC audit
Regulation and Rates [Line Items]
Provision for rate refund	2,724,000	3,482,000
CLECO POWER | TCJA tax-related benefits
Regulation and Rates [Line Items]
Provision for rate refund	2,057,000	28,700,000
CLECO POWER | Cleco Katrina/Rita storm recovery charges
Regulation and Rates [Line Items]
Provision for rate refund	1,630,000	0
CLECO POWER | Cost of service savings
Regulation and Rates [Line Items]
Provision for rate refund	1,483,000	1,851,000
CLECO POWER | Site-specific industrial customer
Regulation and Rates [Line Items]
Provision for rate refund	596,000	844,000
CLECO POWER | Change in transmission ROE
Regulation and Rates [Line Items]
Provision for rate refund	$ 595,000	$ 1,020,000