Summary of Significant Accounting Policies Summary of Significant Accounting Policies, Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Non-vested Stock [Member]	Sep. 30, 2011 Non-vested Stock [Member]	Sep. 30, 2012 Non-vested Stock [Member]	Sep. 30, 2011 Non-vested Stock [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2011 Stock Options [Member]	Sep. 30, 2012 Stock Options [Member]	Sep. 30, 2011 Stock Options [Member]	Sep. 30, 2012 Equity Classification [Member]	Sep. 30, 2011 Equity Classification [Member]	Sep. 30, 2012 Equity Classification [Member]	Sep. 30, 2011 Equity Classification [Member]	Sep. 30, 2012 Cleco Power [Member]	Sep. 30, 2011 Cleco Power [Member]	Sep. 30, 2012 Cleco Power [Member]	Sep. 30, 2011 Cleco Power [Member]	Sep. 30, 2012 Cleco Power [Member] Non-vested Stock [Member]	Sep. 30, 2011 Cleco Power [Member] Non-vested Stock [Member]	Sep. 30, 2012 Cleco Power [Member] Non-vested Stock [Member]	Sep. 30, 2011 Cleco Power [Member] Non-vested Stock [Member]	Sep. 30, 2012 Cleco Power [Member] Stock Options [Member]	Sep. 30, 2011 Cleco Power [Member] Stock Options [Member]	Sep. 30, 2012 Cleco Power [Member] Stock Options [Member]	Sep. 30, 2011 Cleco Power [Member] Stock Options [Member]	Sep. 30, 2012 Cleco Power [Member] Equity Classification [Member]	Sep. 30, 2011 Cleco Power [Member] Equity Classification [Member]	Sep. 30, 2012 Cleco Power [Member] Equity Classification [Member]	Sep. 30, 2011 Cleco Power [Member] Equity Classification [Member]	Mar. 31, 2012 Certain Officers, Key Employees, and Directors [Member] Non-vested Stock [Member]
Stock-Based Compensation [Line Items]
Number of shares granted																																	140,186
Share-based compensation expense	$ 1,988	$ 2,188	$ 4,834	$ 5,730	$ 1,139	$ 1,095	$ 3,271	$ 3,042	$ 2	$ 69	$ 11	$ 105	$ 1,141	$ 1,164	$ 3,282	$ 3,147	$ 639	$ 660	$ 1,423	$ 1,768	$ 301	$ 225	$ 792	$ 748	$ 0	$ 0	$ 0	$ 0	$ 301	$ 225	$ 792	$ 748
Common stock equivalent units	847	1,024	1,552	2,583													338	435	631	1,020
Tax benefit (excluding income tax gross-up)	$ 765	$ 842	$ 1,860	$ 2,205													$ 246	$ 254	$ 548	$ 680