Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 351,015		$ 902,248
Revenue unrelated to contracts with customers
Affiliate revenue	0	$ 0	0	$ 0
Other	7,241		32,029
Total revenue unrelated to contracts with customers	7,241		32,029
Operating revenue, net	358,256	338,499	934,277	897,662
Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	272,616		707,461
Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	139,162		338,357
Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	79,829		218,389
Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	43,380		121,445
Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,039		11,633
Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,206		17,637
Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	61,204		157,995
Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	14,718		41,166
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,477		(4,374)
CLECO POWER | Other
Revenue unrelated to contracts with customers
Other miscellaneous fee revenue	4,900		13,400
Reserve for capital expenditures	200		2,400
Operating Segments | CLECO POWER
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	353,435		909,507
Revenue unrelated to contracts with customers
Affiliate revenue	223	209	651	649
Other	7,241		32,029
Total revenue unrelated to contracts with customers	7,464		32,680
Operating revenue, net	360,899	340,614	942,187	905,104
Operating Segments | CLECO POWER | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	272,616		707,461
Operating Segments | CLECO POWER | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	139,162		338,357
Operating Segments | CLECO POWER | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	79,829		218,389
Operating Segments | CLECO POWER | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	43,380		121,445
Operating Segments | CLECO POWER | Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,039		11,633
Operating Segments | CLECO POWER | Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,206		17,637
Operating Segments | CLECO POWER | Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	63,624		165,255
Operating Segments | CLECO POWER | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	14,718		41,166
Operating Segments | CLECO POWER | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,477		(4,375)
Operating Segments | OTHER
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(2,420)		(7,259)
Revenue unrelated to contracts with customers
Affiliate revenue	22,765		55,707
Other	0		0
Total revenue unrelated to contracts with customers	22,765		55,707
Operating revenue, net	20,345		48,448
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)		(7,260)
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	(22,988)	(13,726)	(56,358)	(42,531)
Other	0		0
Total revenue unrelated to contracts with customers	(22,988)		(56,358)
Operating revenue, net	(22,988)	(13,726)	(56,358)	(42,531)
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	223	209	651	649
Operating revenue, net	360,899	$ 340,614	942,187	$ 905,104
CLECO POWER | Electric customer credits
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,000		24,300
SSR | CLECO POWER | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 600		$ 6,500