Pension Plan and Employee Benefits, Components of Periodic Benefit Costs and Weighted-Average Assumptions (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Benefits [Member]
Components of periodic benefit costs
Service cost	$ 8,390,000	$ 7,451,000	$ 7,010,000
Interest cost	17,629,000	17,145,000	16,454,000
Expected return on plan assets	(24,646,000)	(20,229,000)	(19,464,000)
Transition obligation	0	0	0
Prior period service cost	(71,000)	(71,000)	(71,000)
Net loss	5,556,000	3,156,000	1,930,000
Net periodic benefit cost	6,858,000	7,452,000	5,859,000
Minimum period of required contributions deferral if funding relief is elected (in years)	2 years
Weighted-average assumptions used to determine the benefit obligation as of December 31:
Discount rate (in hundredths)	5.08%	5.43%
Rate of compensation increase (in hundredths)	3.415%	4.265%
Weighted-average assumptions used to determine the net benefit cost (income) for the year ended December 31:
Discount rate (in hundredths)	5.43%	5.91%	6.01%
Rate of compensation increase (in hundredths)	4.119%	4.265%	4.447%
Expected return on plan assets (in hundredths)	7.80%	7.80%	7.80%
Decrease expected return on plan assets	6.61%
Expected increase in expense due to change in investment policies	3,700,000
Pension Benefits [Member] | Other Subsidiaries [Member]
Components of periodic benefit costs
Net periodic benefit cost	2,100,000	1,900,000	1,800,000
Other Benefits [Member]
Components of periodic benefit costs
Service cost	1,532,000	1,511,000	1,414,000
Interest cost	1,818,000	1,965,000	2,140,000
Expected return on plan assets	0	0	0
Transition obligation	20,000	20,000	20,000
Prior period service cost	(206,000)	(2,021,000)	(2,065,000)
Net loss	1,011,000	972,000	897,000
Net periodic benefit cost	4,175,000	2,447,000	2,406,000
Current portion of other benefits liability	3,100,000	3,000,000
Medicare Part D subsidy on postretirement benefit cost	(221,000)	(574,000)
Weighted-average assumptions used to determine the benefit obligation as of December 31:
Discount rate (in hundredths)	4.51%	4.61%
Weighted-average assumptions used to determine the net benefit cost (income) for the year ended December 31:
Discount rate (in hundredths)	4.61%	5.29%	6.27%
Other Benefits [Member] | Cleco Power [Member]
Components of periodic benefit costs
Net periodic benefit cost	3,600,000	2,100,000	2,400,000
Current portion of other benefits liability	2,900,000	2,800,000
Medicare Part D subsidy on postretirement benefit cost			300,000
Allocated amount of other benefits liability	33,200,000	32,300,000
SERP Benefits [Member]
Components of periodic benefit costs
Service cost	1,566,000	1,531,000	1,608,000
Interest cost	2,105,000	2,122,000	2,015,000
Prior period service cost	54,000	54,000	54,000
Net loss	940,000	925,000	777,000
Net periodic benefit cost	4,665,000	4,632,000	4,454,000
Weighted-average assumptions used to determine the benefit obligation as of December 31:
Discount rate (in hundredths)	4.99%	5.26%
Rate of compensation increase (in hundredths)	5.00%	5.00%
Weighted-average assumptions used to determine the net benefit cost (income) for the year ended December 31:
Discount rate (in hundredths)	5.26%	5.78%	6.15%
Rate of compensation increase (in hundredths)	5.00%	5.00%	5.00%
SERP Benefits [Member] | Cleco Power [Member]
Components of periodic benefit costs
Net periodic benefit cost	$ 1,100,000	$ 1,200,000	$ 1,100,000