Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 287,625		$ 551,233
Revenue unrelated to contracts with customers
Affiliate revenue	0	$ 0	0	$ 0
Other	11,636		24,788
Total revenue unrelated to contracts with customers	11,636		24,788
Operating revenue, net	299,261	308,661	576,021	559,162
Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	230,335		434,845
Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	107,805		199,195
Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	71,865		138,560
Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	40,679		78,065
Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,793		7,594
Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,193		11,431
Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	52,242		96,791
Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11,943		26,448
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(6,895)		(6,851)
CLECO POWER | Other
Revenue unrelated to contracts with customers
Other fee revenue	4,100		8,600
Reserve for capital expenditures	300		2,200
Operating Segments | CLECO POWER
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	290,045		556,072
Revenue unrelated to contracts with customers
Affiliate revenue	220	221	428	440
Other	11,636		24,788
Total revenue unrelated to contracts with customers	11,856		25,216
Operating revenue, net	301,901	310,787	581,288	564,489
Operating Segments | CLECO POWER | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	230,335		434,845
Operating Segments | CLECO POWER | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	107,805		199,195
Operating Segments | CLECO POWER | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	71,865		138,560
Operating Segments | CLECO POWER | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	40,679		78,065
Operating Segments | CLECO POWER | Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,793		7,594
Operating Segments | CLECO POWER | Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,193		11,431
Operating Segments | CLECO POWER | Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	54,662		101,631
Operating Segments | CLECO POWER | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	11,943		26,448
Operating Segments | CLECO POWER | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(6,895)		(6,852)
Operating Segments | OTHER
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(2,420)		(4,839)
Revenue unrelated to contracts with customers
Affiliate revenue	17,273	13,631	32,942	28,365
Other	0		0
Total revenue unrelated to contracts with customers	17,273		32,942
Operating revenue, net	14,853	11,726	28,103	23,478
Operating Segments | OTHER | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Operating Segments | OTHER | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Operating Segments | OTHER | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Operating Segments | OTHER | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Operating Segments | OTHER | Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Operating Segments | OTHER | Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Operating Segments | OTHER | Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(2,420)		(4,840)
Operating Segments | OTHER | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Operating Segments | OTHER | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		1
ELIMINATIONS
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
Revenue unrelated to contracts with customers
Affiliate revenue	(17,493)	(13,852)	(33,370)	(28,805)
Other	0		0
Total revenue unrelated to contracts with customers	(17,493)		(33,370)
Operating revenue, net	(17,493)	(13,852)	(33,370)	(28,805)
ELIMINATIONS | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
ELIMINATIONS | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0		0
CLECO POWER
Revenue unrelated to contracts with customers
Affiliate revenue	220	221	428	440
Operating revenue, net	301,901	$ 310,787	581,288	$ 564,489
CLECO POWER | Electric Customer Credits
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	13,600		21,300
SSR | CLECO POWER | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 2,600		$ 5,800