Fair Value Accounting Instruments - Short-term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 172,601	$ 46,279
CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Cash and cash equivalents	99,034	6,813
Current restricted cash and cash equivalents
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	6,356	23,548
Current restricted cash and cash equivalents | CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	6,356	23,548
Non-current restricted cash and cash equivalents
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	112,017	109,414
Non-current restricted cash and cash equivalents | CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	$ 111,994	$ 109,391