Pension Plan and Employee Benefits - Narrative (Details) - USD ($)		3 Months Ended		6 Months Ended
	Mar. 11, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Pension contributions required through 2025	$ 0
Expected contributions in current year		$ 67,000,000.0		$ 67,000,000.0
Defined benefit plan contributions by employer		7,358,000	$ 6,080,000	13,561,000	$ 10,950,000
Pension Plan | Other Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		900,000	1,300,000	1,800,000	1,700,000
Other Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		1,302,000	1,258,000	2,605,000	2,515,000
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	1,200,000	2,400,000	2,500,000
SERP
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		249,000	1,607,000	1,891,000	3,151,000
SERP | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		$ 100,000	$ 200,000	$ 300,000	$ 500,000