Pension Plan and Employee Benefits - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended
	Mar. 11, 2021	Dec. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discretionary contribution		$ 15,800,000
Pension contributions required through 2025	$ 0
Expected contributions in current year			$ 67,000,000.0
Defined benefit plan contributions by employer			6,203,000	$ 4,870,000
Pension Plan | Other Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer			900,000	400,000
Other Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer			1,302,000	1,257,000
Assets held-in-trust, noncurrent			0
Other Benefits Plan | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer			1,200,000	1,200,000
SERP
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer			1,643,000	1,545,000
SERP | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer			$ 300,000	$ 200,000