Miscellaneous Financial Information (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating revenue, net	$ 304,643	$ 371,386	$ 309,070	$ 284,387	$ 263,109	$ 328,763	$ 263,894	$ 240,947	$ 1,269,485	$ 1,096,714	$ 993,697
Operating income	54,729	107,242	66,721	57,338	58,314	116,794	74,754	58,467	286,032	308,332	281,651
Net income applicable to common stock	21,347	70,835	36,633	25,924	25,112	66,407	42,032	27,133	154,739	160,685	163,648
Basic net income per average share (in dollars per share)	$ 0.35	$ 1.17	$ 0.61	$ 0.43	$ 0.42	$ 1.10	$ 0.70	$ 0.45	$ 2.56	$ 2.66	$ 2.71
Diluted net income per average common share (in dollars per share)	$ 0.35	$ 1.17	$ 0.60	$ 0.43	$ 0.41	$ 1.09	$ 0.69	$ 0.45	$ 2.55	$ 2.65	$ 2.70
Dividends on common stock (in dollars per share)	$ 0.40	$ 0.40	$ 0.40	$ 0.3625	$ 0.3625	$ 0.3625	$ 0.3625	$ 0.3375	$ 1.5625	$ 1.425	$ 1.30
Closing market price per share
High (in dollars per share)	$ 55.36	$ 59.21	$ 59.13	$ 50.99	$ 47.79	$ 50.42	$ 49.52	$ 47.17
Low (in dollars per share)	$ 46.11	$ 48.06	$ 49.32	$ 45.52	$ 43.69	$ 43.76	$ 43.75	$ 40.39
Cleco Power [Member]
Operating revenue, net	304,432	371,178	308,859	284,180	262,900	328,556	263,725	240,778	1,268,649	1,095,959	993,067
Operating income	66,189	108,303	67,032	58,188	60,678	111,663	72,579	61,765	299,715	306,681	287,194
Net income	29,806	65,544	32,658	26,307	26,268	61,885	34,464	27,793
Contributions from Cleco Corporation	0	0	0	138,080					138,080
Distribution to Cleco Corporation (as sole member)	$ (30,000)	$ (15,000)	$ (35,000)	$ (35,000)	$ (30,000)	$ (50,000)	$ (25,000)	$ 0	$ (115,000)	$ (105,000)	$ (58,000)