Fair Value Accounting - Fair Value Measurement Inputs and Valuation Techniques (Details) $ in Thousands	Dec. 31, 2018 USD ($) $ / MW	Dec. 31, 2017 USD ($) $ / MW
MINIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FORWARD PRICE RANGE (usd per MWh) | $ / MW	(4.40)	(2.95)
MAXIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FORWARD PRICE RANGE (usd per MWh) | $ / MW	15.10	6.33
Measured On A Recurring Basis
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets	$ 23,355	$ 7,396
Liabilities	468	352
Measured On A Recurring Basis | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets	23,355	7,396
Liabilities	$ 468	$ 352
CLECO POWER | MINIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FORWARD PRICE RANGE (usd per MWh) | $ / MW	(4.40)	(2.95)
CLECO POWER | MAXIMUM
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
FORWARD PRICE RANGE (usd per MWh) | $ / MW	15.10	6.33
CLECO POWER | Measured On A Recurring Basis
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets	$ 23,355	$ 7,396
Liabilities	468	352
CLECO POWER | Measured On A Recurring Basis | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets	23,355	7,396
Liabilities	$ 468	$ 352