Pension Plan and Employee Benefits, Pension Plan and Other Benefits Plan (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
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	$ 2,484,000	$ 2,149,000
Interest cost	4,437,000	4,430,000
Expected return on plan assets	(5,764,000)	(5,194,000)
Transition obligation	0	0
Prior period service cost	(18,000)	(18,000)
Net loss	3,373,000	1,783,000
Net periodic benefit cost	4,512,000	3,150,000
Discretionary contributions to the pension plan			0
Pension Benefits [Member] | Cleco Power [Member]
Components of periodic benefit costs
Discretionary contributions to the pension plan	34,000,000
Pension Benefits [Member] | Other Subsidiaries [Member]
Components of periodic benefit costs
Net periodic benefit cost	600,000	500,000
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
Components of periodic benefit costs
Service cost	314,000	397,000
Interest cost	481,000	476,000
Expected return on plan assets	0	0
Transition obligation	4,000	5,000
Prior period service cost	0	0
Net loss	318,000	200,000
Net periodic benefit cost	1,117,000	1,078,000
Other Benefits [Member] | Cleco Power [Member]
Defined Benefit Plan Disclosure [Line Items]
Current portion of other benefits liability	2,900,000		2,900,000
Components of periodic benefit costs
Net periodic benefit cost	$ 1,000,000	$ 900,000