Schedule I Financial Statements of Cleco Corporation, Condensed Statements of Income (Details) - USD ($) $ in Thousands		3 Months Ended									9 Months Ended		12 Months Ended
	Apr. 12, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Apr. 12, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2015
Successor [Member]
Operating expenses [Abstract]
Merger transaction costs												$ 174,696	$ 287
Total operating expenses												816,714	921,357
Operating income (loss)		$ 50,130	$ 95,112	$ 70,249	$ 38,798	$ 53,299	$ 93,143	$ (110,148)				36,291	254,289
Other income												3,350	6,474
Other expense												(1,385)	(2,435)
Income (loss) before income taxes												(46,935)	145,159
Federal and state income tax benefit												(22,822)	7,079
Net income (loss)		$ 61,040	$ 45,304	$ 25,444	$ 6,292	$ 18,180	$ 39,621	$ (81,914)			$ (24,113)	(24,113)	138,080
Successor [Member] | Cleco Holdings [Member]
Operating expenses [Abstract]
Administrative and general												375	5,042
Merger transaction costs												23,211	287
Other operating expense												(382)	685
Total operating expenses												23,204	6,014
Operating income (loss)												(23,204)	(6,014)
Equity income from subsidiaries, net of tax												9,357	170,706
Interest, net												(35,151)	(53,684)
Other income												1,948	3,978
Other expense												0	0
Income (loss) before income taxes												(47,050)	114,986
Federal and state income tax benefit												(22,937)	(23,094)
Net income (loss)												$ (24,113)	$ 138,080
Predecessor [Member]
Operating expenses [Abstract]
Merger transaction costs									$ 34,912					$ 4,591
Total operating expenses									279,507					922,063
Operating income (loss)	$ (29,832)								20,363	$ 50,192				287,339
Other income									870					1,443
Other expense									(590)					(3,376)
Income (loss) before income taxes									(492)					211,373
Federal and state income tax benefit									3,468					77,704
Net income (loss)	$ (23,328)								(3,960)	$ 19,368				133,669
Predecessor [Member] | Cleco Holdings [Member]
Operating expenses [Abstract]
Administrative and general									319					1,891
Merger transaction costs									34,912					4,591
Other operating expense									624					490
Total operating expenses									35,855					6,972
Operating income (loss)									(35,855)					(6,972)
Equity income from subsidiaries, net of tax									21,789					141,636
Interest, net									(286)					(1,731)
Other income									702					17
Other expense									0					(1,142)
Income (loss) before income taxes									(13,650)					131,808
Federal and state income tax benefit									(9,690)					(1,861)
Net income (loss)									$ (3,960)					$ 133,669