Income Taxes - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance [Line Items]
Interest payable related to uncertain tax positions	$ 0	$ 0	$ 0
Interest expense related to uncertain tax positions		0	0	$ 0
Liability for uncertain tax positions	0	0	0
Penalties recognized		0	0
Decreased ADIT liability	(421,200,000)
Accumulated deferred federal and state income taxes, net	(608,030,000)	(657,058,000)	(608,030,000)
Taxes payable, net	43,674,000	8,931,000	43,674,000
Other deferred charges	20,846,000	27,222,000	20,846,000
Scenario, Adjustment
Valuation Allowance [Line Items]
Accrued Income Taxes, Current And Other Liabilities, Noncurrent		2,800,000
Accumulated deferred federal and state income taxes, net	7,600,000		7,600,000
Taxes payable, net	3,800,000	1,400,000	3,800,000
Other deferred charges	3,800,000	1,400,000	3,800,000
NMTC
Valuation Allowance [Line Items]
NMTC carryforwards		92,400,000
Net operating loss carryforwards	86,900,000		86,900,000
Valuation allowance		0
CLECO POWER
Valuation Allowance [Line Items]
Valuation allowance		0
Interest payable related to uncertain tax positions	0	0	0
Interest expense related to uncertain tax positions		0	0	$ 0
Liability for uncertain tax positions	0	0	0
Decreased ADIT liability	(389,300,000)
Accumulated deferred federal and state income taxes, net	(630,765,000)	(657,834,000)	(630,765,000)
Taxes payable, net	48,177,000	38,888,000	48,177,000
Other deferred charges	$ 18,345,000	20,187,000	$ 18,345,000
Federal | Scenario, Adjustment
Valuation Allowance [Line Items]
Net operating loss carryforwards		536,500,000
State | Scenario, Adjustment
Valuation Allowance [Line Items]
Net operating loss carryforwards		$ 68,700,000