Litigation, Other Commitments and Contingencies, and Disclosures about Guarantees, Litigation (Details) (USD $)	1 Months Ended		12 Months Ended				3 Months Ended		12 Months Ended
	Sep. 30, 2011 Discrimiation Complaint [Member] claim plaintiff	Apr. 30, 2011 Discrimiation Complaint [Member] claim	Dec. 31, 2010 Discrimiation Complaint [Member]	Jul. 29, 2010 Discrimiation Complaint [Member] plaintiff	Jul. 31, 2012 Retaliation complaint [Member] plaintiff	Sep. 30, 2012 Other Litigation Matters [Member]	Sep. 30, 2012 Cleco Power [Member]	Mar. 09, 2010 Cleco Power [Member] City of Opelousas Litigation [Member] resident claim	Dec. 31, 2009 Minimum [Member] Discrimiation Complaint [Member]	Mar. 09, 2010 Minimum [Member] Cleco Power [Member] City of Opelousas Litigation [Member]	Jul. 29, 2010 Current Employee [Member] Discrimiation Complaint [Member] employee	Dec. 11, 2009 Current Employee [Member] Discrimiation Complaint [Member] employee	Jul. 31, 2012 Current Employee [Member] Retaliation complaint [Member] employee	Dec. 11, 2009 Former Employee [Member] Discrimiation Complaint [Member] employee	Jul. 31, 2012 Former Employee [Member] Retaliation complaint [Member] employee	Mar. 09, 2010 Customer [Member] Cleco Power [Member] City of Opelousas Litigation [Member] customer
Litigation [Abstract]
Number of plaintiffs											1	8	6	4	3	3
Minimum amount sought by plaintiffs									$ 35,000,000
Minimum amount sought by additional plaintiff			2,500,000
Total number of plaintiffs				13	9
Number of claims settled and dismissed	1	1
Number of plaintiffs remaining	11
Amount owed as a result of alleged overcharges						2,500,000				30,000,000
Number of residents in second class action lawsuit								249
Number of class action law suits								2
Fuel expenses included in audit							3,260,000,000
Cost disallowance in audit, excluding interest							400,000
Customer fuel credit refund							400,000
Environmental expenses included in audit							$ 11,300,000