Pension Plan and Employee Benefits, Pension Plan and Other Benefits Plan (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
General information			Benefits under the plan reflect an employee’s years of service, age at retirement, and highest total average compensation for any consecutive five calendar years during the last 10 years of employment with Cleco.
Components of periodic benefit costs
Service cost	$ 2,078,000	$ 2,097,000	$ 6,234,000	$ 6,292,000
Interest cost	4,563,000	4,407,000	13,690,000	13,222,000
Expected return on plan assets	(5,201,000)	(6,161,000)	(15,604,000)	(18,484,000)
Transition obligation	0	0	0	0
Prior period service cost	(18,000)	(18,000)	(53,000)	(54,000)
Net loss	2,087,000	1,389,000	6,259,000	4,167,000
Net periodic benefit cost	3,509,000	1,714,000	10,526,000	5,143,000
Discretionary contributions to the pension plan			0		60,000,000
Pension Benefits [Member] | Other Subsidiaries [Member]
Components of periodic benefit costs
Net periodic benefit cost	500,000	500,000	1,600,000	1,600,000
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
General information			Cleco’s retirees and their dependents are eligible to receive medical, dental, vision, and life insurance benefits (other benefits).
Current portion of other benefits liability	3,100,000		3,100,000		3,100,000
Components of periodic benefit costs
Service cost	303,000	390,000	1,096,000	1,149,000
Interest cost	334,000	443,000	1,287,000	1,364,000
Expected return on plan assets	0	0	0	0
Transition obligation	5,000	5,000	15,000	15,000
Prior period service cost	0	(51,000)	0	(154,000)
Net loss	112,000	246,000	512,000	758,000
Net periodic benefit cost	754,000	1,033,000	2,910,000	3,132,000
Other Benefits [Member] | Cleco Power [Member]
Defined Benefit Plan Disclosure [Line Items]
Current portion of other benefits liability	2,900,000		2,900,000		2,900,000
Components of periodic benefit costs
Net periodic benefit cost	700,000	900,000	2,500,000	2,700,000
Prior Plan Year [Member] | Pension Benefits [Member]
Components of periodic benefit costs
Contributions designated for prior plan year					40,100,000
Current Plan Year [Member] | Pension Benefits [Member]
Components of periodic benefit costs
Contributions designated for current plan year					$ 19,900,000