Pension Plan and Employee Benefits - Narrative (Details) - USD ($)		3 Months Ended		9 Months Ended
	Mar. 11, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension contributions required through 2025	$ 0
Special/contractual termination benefits, percent increase in benefits		10.00%		10.00%
Special/contractual termination benefits		$ 3,270,000	$ 0	$ 3,270,000	$ 0
Defined benefit plan contributions by employer		10,050,000	5,473,000	23,610,000	16,423,000
Pension Plan | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Special/contractual termination benefits				2,400,000
Pension Plan | Support Group
Defined Benefit Plan Disclosure [Line Items]
Special/contractual termination benefits				900,000
Pension Plan | Other Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		1,800,000	900,000	3,600,000	2,600,000
Other Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Special/contractual termination benefits		0	0	0	0
Defined benefit plan contributions by employer		1,319,000	1,380,000	3,924,000	3,895,000
Assets held-in-trust, noncurrent		0		0
Other Benefits Plan | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		1,200,000	1,100,000	3,600,000	3,600,000
SERP
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		946,000	1,575,000	2,837,000	4,726,000
SERP | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		$ 100,000	$ 200,000	$ 400,000	$ 700,000