Fair Value Accounting - Narrative (Details) MWh in Millions, MMBTU in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) MMBTU	Dec. 31, 2019 USD ($) MWh	Dec. 31, 2018 USD ($) MWh
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 103,400,000	$ 103,400,000	$ 103,800,000
Fair value transfers, amount	$ 0	$ 0	$ 0
Energy of other commodity derivatives held (MWh / MMBtu)	58.5	14.6	8.7
Restricted Cash and Cash Equivalents, Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash and cash equivalents	$ 11,100,000	$ 11,100,000	$ 11,200,000
Restricted Cash and Cash Equivalents, Noncurrent
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash and cash equivalents	15,100,000	15,100,000	18,700,000
CLECO POWER
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	49,500,000	$ 49,500,000	$ 26,100,000
Energy of other commodity derivatives held (MWh / MMBtu) | MWh		9.2	8.7
CLECO POWER | Restricted Cash and Cash Equivalents, Current
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash and cash equivalents	11,100,000	$ 11,100,000	$ 11,200,000
CLECO POWER | Restricted Cash and Cash Equivalents, Noncurrent
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash and cash equivalents	$ 14,300,000	$ 14,300,000	$ 18,600,000