Disclosures about Segments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) entity	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) entity	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of transmission interconnection facility subsidiaries | entity	2		2
Revenue
Electric operations	$ 294,213	$ 287,435	$ 556,424	$ 521,491
Other operations	18,685	21,465	40,881	38,345
Electric customer credits	(13,637)	(239)	(21,284)	(674)
Affiliate revenue	0	0	0	0
Operating revenue, net	299,261	308,661	576,021	559,162
Depreciation and amortization	41,807	41,552	84,314	82,402
Interest charges	31,909	30,621	63,067	62,339
Interest income	1,427	381	2,211	693
Federal and state income tax expense (benefit)	7,665	16,220	10,528	19,327
Net income (loss)	25,839	25,444	36,700	31,736
Additions to property, plant, and equipment		128,693	135,702	128,693
Equity investment in investee	18,172		18,172		$ 18,172
Goodwill	1,490,797		1,490,797		1,490,797
Total segment assets	6,385,611		6,385,611		6,278,382
Operating Segments | CLECO POWER
Revenue
Electric operations	296,633	289,855	561,264	527,408
Other operations	18,685	20,950	40,880	37,315
Electric customer credits	(13,637)	(239)	(21,284)	(674)
Affiliate revenue	220	221	428	440
Operating revenue, net	301,901	310,787	581,288	564,489
Depreciation and amortization	39,720	39,473	80,109	78,230
Interest charges	18,107	17,411	35,763	35,515
Interest income	1,313	328	1,953	594
Federal and state income tax expense (benefit)	13,710	23,063	21,707	32,918
Net income (loss)	43,020	35,733	69,024	53,587
Additions to property, plant, and equipment		127,297	135,334
Equity investment in investee	18,172		18,172		18,172
Goodwill	1,490,797		1,490,797		1,490,797
Total segment assets	5,807,559		5,807,559		5,679,538
Operating Segments | OTHER
Revenue
Electric operations	(2,420)	(2,420)	(4,840)	(5,917)
Other operations	0	515	1	1,030
Electric customer credits	0	0	0	0
Affiliate revenue	17,273	13,631	32,942	28,365
Operating revenue, net	14,853	11,726	28,103	23,478
Depreciation and amortization	2,086	2,079	4,205	4,172
Interest charges	13,843	13,285	27,392	26,966
Interest income	152	127	342	240
Federal and state income tax expense (benefit)	(6,045)	(6,843)	(11,180)	(13,591)
Net income (loss)	(17,182)	(10,289)	(32,324)	(21,851)
Additions to property, plant, and equipment		1,396	368
Equity investment in investee	0		0		0
Goodwill	0		0		0
Total segment assets	599,216		599,216		619,943
ELIMINATIONS
Revenue
Electric operations	0	0	0	0
Other operations	0	0	0
Electric customer credits	0	0	0	0
Affiliate revenue	(17,493)	(13,852)	(33,370)	(28,805)
Operating revenue, net	(17,493)	(13,852)	(33,370)	(28,805)
Depreciation and amortization	1	0	0	0
Interest charges	(41)	(75)	(88)	(142)
Interest income	(38)	(74)	(84)	(141)
Federal and state income tax expense (benefit)	0	0	1	0
Net income (loss)	1	0	0	$ 0
Additions to property, plant, and equipment		$ 0	0
Equity investment in investee	0		0		0
Goodwill	0		0		0
Total segment assets	$ (21,164)		$ (21,164)		$ (21,099)