Fair Value Accounting Instruments - Carrying Value and Estimated Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred debt issuance costs not included in the carrying value of long-term debt	$ 14,200	$ 16,200
CARRYING VALUE
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,400,293	3,482,556
FAIR VALUE
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,177,654	3,180,208
CLECO POWER
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred debt issuance costs not included in the carrying value of long-term debt	11,500	12,300
CLECO POWER | CARRYING VALUE
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	1,886,248	1,895,508
CLECO POWER | FAIR VALUE
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 1,867,559	$ 1,825,192