Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate [Line Items]
Income before tax	$ 158,018	$ 195,830	$ 123,819
Statutory rate	21.00%	21.00%	21.00%
Tax expense at federal statutory rate	$ 33,184	$ 41,124	$ 26,002
Increase (decrease)
Plant differences, including AFUDC flowthrough	5,100	(4,687)	(401)
State income taxes, net of federal benefit	7,190	9,565	6,288
Return to accrual adjustment	7,218	(3,963)	(193)
NMTC	0	0	(1,578)
Amortization of excess ADIT	(16,667)	0	0
Other, net	(307)	1,126	(736)
Total tax expense	$ 35,718	$ 43,165	$ 29,382
Effective rate	22.60%	22.00%	23.70%
CLECO POWER
Effective Income Tax Rate [Line Items]
Income before tax	$ 123,454	$ 193,714	$ 218,181
Statutory rate	21.00%	21.00%	21.00%
Tax expense at federal statutory rate	$ 25,925	$ 40,680	$ 45,818
Increase (decrease)
Plant differences, including AFUDC flowthrough	5,100	(4,687)	(401)
State income taxes, net of federal benefit	6,303	11,683	11,080
Return to accrual adjustment	7,082	(2,008)	483
Amortization of excess ADIT	(16,667)	0	0
Other, net	(944)	(216)	(1,056)
Total tax expense	$ 26,799	$ 45,452	$ 55,924
Effective rate	21.70%	23.50%	25.60%