Pension Plan and Employee Benefits - Narrative (Details) - USD ($)		3 Months Ended
	Mar. 30, 2017	Mar. 31, 2018	Mar. 31, 2017	Mar. 29, 2017
PENSION BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		$ 4,580,000	$ 3,840,000
OTHER BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		700,000	785,000
Assets held-in-trust, noncurrent		0
SERP Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		1,415,000	1,622,000
Defined benefit plan, assumptions used calculating benefit obligation, discount rate	4.08%			4.22%
Defined benefit plan, net periodic benefit cost (credit), gain (loss) due to settlement	$ (300,000)	0	(315,000)
Cleco Power | OTHER BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		800,000	900,000
Cleco Power | SERP Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		300,000	300,000
Other Subsidiaries | PENSION BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		$ 500,000	$ 400,000