Fair Value Accounting and Financial Instruments - Carrying Value and Estimated Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred debt issuance costs not included in the carrying value of long-term debt	$ 13,200	$ 13,400
CARRYING VALUE*
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,482,405	3,230,500
FAIR VALUE
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,752,220	3,541,349
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	7,900	7,000
CLECO POWER | CARRYING VALUE*
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	1,820,254	1,494,947
CLECO POWER | FAIR VALUE
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 2,085,944	$ 1,794,799