Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees - Risks and Uncertainties (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2021
Loss Contingencies [Line Items]
Revisions and adjustments			$ 48,641
CLECO POWER
Loss Contingencies [Line Items]
Revisions and adjustments		$ 13,100	13,101
CLECO POWER | Dolet Hills Power Station
Loss Contingencies [Line Items]
Revisions and adjustments	$ 3,300
Investment balance		38,600	38,600
CLECO POWER | Dolet Hills Power Station | DHLC
Loss Contingencies [Line Items]
Costs to be billed		10,100	10,100
CLECO POWER | Oxbow | Oxbow
Loss Contingencies [Line Items]
Costs to be billed		$ 1,800	$ 1,800