Income Taxes - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
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	0
Decreased deferred income tax expense			46,300,000
Decreased ADIT liability	26,400,000		394,900,000
Accumulated deferred federal and state income taxes, net	(608,030,000)	(608,030,000)	(614,812,000)
Taxes payable, net	43,674,000	43,674,000	22,698,000
Other deferred charges	25,874,000	25,874,000	31,635,000
Scenario, Adjustment
Valuation Allowance [Line Items]
Accumulated deferred federal and state income taxes, net	7,600,000	7,600,000
Taxes payable, net and Other deferred charges	7,600,000	7,600,000
Taxes payable, net	3,800,000	3,800,000
Other deferred charges	3,800,000	3,800,000
NMTC
Valuation Allowance [Line Items]
NMTC carryforwards	86,900,000	86,900,000
Net operating loss carryforwards			97,500,000
Valuation allowance	0	0
CLECO POWER
Valuation Allowance [Line Items]
Valuation allowance	0	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 deferred income tax expense			14,300,000
Decreased ADIT liability	26,400,000		362,900,000
Accumulated deferred federal and state income taxes, net	(630,765,000)	(630,765,000)	(656,362,000)
Taxes payable, net	48,177,000	48,177,000	31,611,000
Other deferred charges	23,373,000	23,373,000	$ 29,576,000
Federal
Valuation Allowance [Line Items]
Net operating loss carryforwards	0	0
State
Valuation Allowance [Line Items]
Net operating loss carryforwards	$ 0	$ 0