Summary of Significant Accounting Policies, Property, Plant and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Abstract]
Capitalized Computer Software, Gross	$ 5,300,000	$ 3,300,000
Amortization of capitalized computer software costs	1,200,000	1,500,000	1,700,000
Useful lives of property, plant and equipment [Abstract]
Utility plant (in years)	5-58
Other (in years)	5-44
Property, plant, and equipment, net [Abstract]
Regulated utility plants	3,871,940,000	3,759,541,000
Other	268,254,000	264,114,000
Property, plant and equipment	4,140,194,000	4,023,655,000
Accumulated depreciation	(1,311,273,000)	(1,230,783,000)
Net property, plant, and equipment	2,828,921,000	2,792,872,000
Cleco Power [Member]
Property, Plant and Equipment [Abstract]
Annual depreciation provisions expressed as a percentage of average depreciable property (in hundredths)	2.68%	2.80%	2.55%
Property, plant, and equipment, net [Abstract]
Property, plant and equipment	3,871,940,000	3,759,541,000
Accumulated depreciation	(1,227,078,000)	(1,153,004,000)
Net property, plant, and equipment	$ 2,644,862,000	$ 2,606,537,000