Debt, Long-Term Debt (Details) (USD $)	12 Months Ended								0 Months Ended		1 Months Ended																																															12 Months Ended										12 Months Ended				1 Months Ended	12 Months Ended						12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Cleco Power [Member]	Dec. 31, 2011 Cleco Power [Member]	Dec. 31, 2010 Cleco Power [Member]	Dec. 31, 2012 Cleco Powers Senior Notes 4.33% due 2027 [Member]	Dec. 31, 2012 Capital Lease Obligations [Member]	Oct. 07, 2011 Line of Credit [Member] Cleco Power [Member]	Dec. 31, 2012 Line of Credit [Member] Cleco Power [Member]	Nov. 30, 2010 Line of Credit [Member] Cleco Corporation [Member]	Dec. 31, 2012 Line of Credit [Member] Cleco Corporation's credit facility draws [Member]	Dec. 31, 2011 Line of Credit [Member] Cleco Corporation's credit facility draws [Member]	Dec. 31, 2012 Bonds [Member]	Dec. 31, 2011 Bonds [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 5.375%, due 2013 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 5.375%, due 2013 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 5.375%, due 2013 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 5.375%, due 2013 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 4.95%, due 2015 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 4.95%, due 2015 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 4.95%, due 2015 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 4.95%, due 2015 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 6.65%, due 2018 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 6.65%, due 2018 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 6.65%, due 2018 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 6.65%, due 2018 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Powers Senior Notes 4.33% due 2027 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Powers Senior Notes 4.33% due 2027 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Powers Senior Notes 4.33% due 2027 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Powers Senior Notes 4.33% due 2027 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 6.50%, due 2035 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 6.50%, due 2035 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 6.50%, due 2035 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 6.50%, due 2035 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 5.942%, due 2040 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 5.942%, due 2040 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes, 5.942%, due 2040 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes, 5.942%, due 2040 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes 5.988% due 2041 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes 5.988% due 2041 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's senior notes 5.988% due 2041 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's senior notes 5.988% due 2041 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's pollution control revenue bonds, 5.875%, due 2029, callable after September 1, 2009 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's pollution control revenue bonds, 5.875%, due 2029, callable after September 1, 2009 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's pollution control revenue bonds, 5.875%, due 2029, callable after September 1, 2009 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's pollution control revenue bonds, 5.875%, due 2029, callable after September 1, 2009 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 4.70%, due 2036, callable after November 1, 2016 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 4.70%, due 2036, callable after November 1, 2016 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 4.70%, due 2036, callable after November 1, 2016 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 4.70%, due 2036, callable after November 1, 2016 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 5.25%, due 2037, mandatory tender on March 1, 2013 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 5.25%, due 2037, mandatory tender on March 1, 2013 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 5.25%, due 2037, mandatory tender on March 1, 2013 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's solid waste disposal facility bonds, 5.25%, due 2037, mandatory tender on March 1, 2013 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Katrina/Ritas Storm Recovery Bonds [Member]	Dec. 31, 2012 Bonds [Member] Cleco Katrina/Ritas Storm Recovery Bonds [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 4.41%, due 2020 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 4.41%, due 2020 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 4.41%, due 2020 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 4.41%, due 2020 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 5.61%, due 2023 [Member]	Dec. 31, 2011 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 5.61%, due 2023 [Member]	Dec. 31, 2012 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 5.61%, due 2023 [Member] Cleco Power [Member]	Dec. 31, 2011 Bonds [Member] Cleco Katrina/Rita's storm recovery bonds, 5.61%, due 2023 [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] DeSoto Parish pollution control revenue bonds [Member]	Dec. 31, 2012 Bonds [Member] DeSoto Parish pollution control revenue bonds [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Corporation's credit facility draws [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's Rapides Parish pollution control revenue bonds [Member]	Dec. 31, 2011 Bonds [Member] Cleco Power's Rapides Parish pollution control revenue bonds [Member] Cleco Power [Member]	Dec. 31, 2012 Bonds [Member] Cleco Power's Rapides Parish pollution control revenue bonds [Member] Cleco Power [Member]	Dec. 31, 2012 Capital Lease Obligations [Member]	Dec. 31, 2012 Capital Lease Obligations [Member] Barge lease obligations, ending December 31, 2017 [Member]	Dec. 31, 2011 Capital Lease Obligations [Member] Barge lease obligations, ending December 31, 2017 [Member]	Dec. 31, 2012 Capital Lease Obligations [Member] Barge lease obligations, ending December 31, 2017 [Member] Cleco Power [Member]	Dec. 31, 2011 Capital Lease Obligations [Member] Barge lease obligations, ending December 31, 2017 [Member] Cleco Power [Member]	Dec. 31, 2012 Capital Lease Obligations [Member] Cleco Power [Member]
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 1,350,000,000	$ 1,360,000,000		$ 1,320,000,000	$ 1,350,000,000
Maturity date									Oct. 07, 2016		Oct. 07, 2016
Gross amount of long-term debt	1,356,548,000	1,372,105,000		1,331,548,000	1,362,105,000													75,000,000	75,000,000	75,000,000	75,000,000	50,000,000	50,000,000	50,000,000	50,000,000	250,000,000	250,000,000	250,000,000	250,000,000	50,000,000	0	50,000,000	0	295,000,000	295,000,000	295,000,000	295,000,000	250,000,000	250,000,000	250,000,000	250,000,000	100,000,000	100,000,000	100,000,000	100,000,000	0	61,260,000	0	61,260,000	60,000,000	60,000,000	60,000,000	60,000,000	60,000,000	60,000,000	60,000,000	60,000,000			62,598,000	75,707,000	62,598,000	75,707,000	67,600,000	67,600,000	67,600,000	67,600,000
Long-term Debt, Gross														1,320,198,000	1,344,567,000	1,320,198,000	1,344,567,000
Capital Lease Obligations																																																																											11,350,000	17,538,000	11,350,000	17,538,000
Line of Credit Facility, Amount Outstanding										0		25,000,000	10,000,000
Less: long-term debt due within one year	88,969,000	24,258,000		88,969,000	24,258,000													75,000,000		75,000,000																										11,200,000												14,000,000	14,000,000
Less: lease obligations classified as long-term debt due within one year	2,171,000	1,841,000		2,171,000	1,841,000																																																																					2,100,000
Debt Instrument, Increase (Decrease) for Period, Net	(14,800,000)			(29,800,000)				6,200,000																																																																							6,200,000
Less: unamortized premium and discount, net	(8,150,000)	(8,950,000)		(8,150,000)	(8,950,000)
Long-term debt, net	1,257,258,000	1,337,056,000		1,232,258,000	1,327,056,000
Interest rate (in hundredths)							4.33%																																					5.12%																								5.875%			5.875%
Debt Instrument, Maturity Date							May 15, 2027																																																													Sep. 01, 2029			Sep. 01, 2029
Long-term Debt and Capital Lease Obligations, Current	91,140,000	26,099,000		91,140,000	26,099,000
Repayments of long-term debt	74,368,000	12,269,000	120,867,000	74,368,000	12,269,000	85,704,000
Interest Paid																																																																				600,000				300,000
Amounts payable under long-term debt agreements [Abstract]
2013	88,969,000	24,258,000		88,969,000	24,258,000													75,000,000		75,000,000																										11,200,000												14,000,000	14,000,000
2014	14,876,000			14,876,000
2015	90,824,000			65,824,000
2016	16,814,000			16,814,000
2017	17,896,000			17,896,000
Thereafter	1,115,819,000			1,115,819,000
Extinguishment of Debt, Amount																																																																				(50,100,000)	(50,100,000)		(11,200,000)		(11,200,000)
Debt Instrument, Face Amount							50,000,000																									50,000,000
Line of Credit Facility, Increase (Decrease) for Period, Net																																																																						15,000,000
Amortization of Debt Discount (Premium)	800,000			800,000
Debt Instrument, Periodic Payment, Principal																																																										$ (13,100,000)	$ (13,100,000)