Pension Plan and Employee Benefits - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discretionary contribution	$ 12,300,000
Pension contributions required through 2024						$ 66,500,000
Defined benefit plan contributions by employer		$ 6,080,000	$ 3,136,000	$ 10,950,000	$ 6,088,000
Pension Plan | Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected contributions in 2020						$ 15,500,000
Pension Plan | Other Subsidiaries
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		1,300,000	600,000	1,700,000	1,100,000
Other Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		1,258,000	645,000	2,515,000	1,288,000
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	700,000	2,500,000	1,500,000
SERP
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		1,607,000	1,225,000	3,151,000	2,520,000
SERP | CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan contributions by employer		$ 200,000	$ 100,000	$ 500,000	$ 400,000