Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation Allowance [Line Items]
Interest payable related to uncertain tax positions	$ 0	$ 0
Interest expense related to uncertain tax positions	0	0	$ 0
Liability for uncertain tax positions	0	0
Penalties recognized	0	0	0
Other deferred charges	28,627,000	27,222,000
Scenario, Adjustment
Valuation Allowance [Line Items]
Other deferred charges		1,400,000
LPSC | Excess A D I T
Valuation Allowance [Line Items]
Regulatory liability	352,400,000	375,000,000.0
NMTC
Valuation Allowance [Line Items]
NMTC carryforwards	92,400,000	92,400,000
Valuation allowance	0
CLECO POWER
Valuation Allowance [Line Items]
Interest payable related to uncertain tax positions	0	0
Interest expense related to uncertain tax positions	0	0	$ 0
Liability for uncertain tax positions	0	0
Regulatory liability	180,565,000	153,623,000
Other deferred charges	18,167,000	20,187,000
CLECO POWER | LPSC | Excess A D I T
Valuation Allowance [Line Items]
Regulatory liability	352,400,000	375,000,000.0
CLECO POWER | NMTC
Valuation Allowance [Line Items]
Valuation allowance	0
Federal
Valuation Allowance [Line Items]
Net operating loss carryforwards	65,000,000.0	$ 433,200,000
Federal | CLECO POWER
Valuation Allowance [Line Items]
Net operating loss carryforwards	136,300,000
State
Valuation Allowance [Line Items]
Net operating loss carryforwards	134,600,000
State | CLECO POWER
Valuation Allowance [Line Items]
Net operating loss carryforwards	$ 134,600,000