Pension Plan and Employee Benefits - Narrative (Details)		1 Months Ended		12 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) bonus	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
401(k) one time benefit, percent of employee's gross pay	30.00%	30.00%
401(k) Plan expense, additional cost	$ 200,000
PENSION BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Consecutive calendar years					5 years
Most recent period of employment					10 years
Employer contributions			$ 15,800,000
Estimated pension contributions required through 2027					$ 74,500,000
Defined benefit plan, interest crediting rate					5.07%	3.06%
Net actuarial gain (loss) occurring during the period					$ 58,124,000	$ 26,925,000
Special/contractual termination benefits, percent increase in benefits	10.00%	10.00%
Special/contractual termination benefits					0	3,270,000	$ 0
Net periodic benefit cost					$ 16,056,000	$ 30,391,000	$ 21,894,000
Discount rate					2.98%	2.74%	3.43%
Expected return on plan assets					5.25%	5.00%	5.91%
Actual return on plan assets					(19.94%)	(7.14%)
SERP net actuarial gain					$ 174,733,000	$ 9,823,000
PENSION BENEFITS | Forecast
Defined Benefit Plan Disclosure [Line Items]
Discount rate				5.44%
Expected return on plan assets				6.60%
Decrease in expected pension costs				$ 14,400,000
PENSION BENEFITS | Other Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost					3,200,000	4,500,000	$ 3,500,000
PENSION BENEFITS | Support Group
Defined Benefit Plan Disclosure [Line Items]
Special/contractual termination benefits		$ 900,000
PENSION BENEFITS | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Special/contractual termination benefits		$ 2,400,000
OTHER BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss) occurring during the period					10,289,000	81,000
Special/contractual termination benefits					0	0	0
Net periodic benefit cost					4,898,000	$ 5,231,000	$ 5,193,000
Assets set aside in a trust					$ 0
Discount rate					2.82%	2.39%	3.25%
Assumed health care cost trend rates for next fiscal year					5.00%
Assumed health care cost trend rates thereafter next fiscal year					5.00%
Ultimate health care trend rate					5.00%
SERP net actuarial gain					$ 10,289,000	$ 81,000
OTHER BENEFITS | MAXIMUM
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss) occurring during the period						100,000
OTHER BENEFITS | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost					$ 4,400,000	4,700,000	$ 4,800,000
SERP BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Consecutive calendar years					5 years
Most recent period of employment					60 months
Net actuarial gain (loss) occurring during the period					$ 22,097,000	1,932,000
Net periodic benefit cost					$ 3,740,000	$ 3,783,000	$ 6,302,000
Discount rate					2.95%	2.64%	3.37%
Number of highest cash bonuses | bonus					5
SERP net actuarial gain					$ 22,097,000	$ 1,932,000
SERP BENEFITS | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost					$ 600,000	$ 600,000	$ 1,000,000