Fair Value Accounting Instruments - Short-term Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 164,047	$ 113,207
CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Cash and cash equivalents	49,444	40,240
Current restricted cash and cash equivalents
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	7,684	15,818
Current restricted cash and cash equivalents | CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	7,684	15,818
Non-current restricted cash and cash equivalents
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	114,976	113,571
Non-current restricted cash and cash equivalents | CLECO POWER
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Restricted cash and cash equivalents	$ 114,952	$ 113,548