Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									$ 1,189,178
Electric customer credits									(33,195)
Total revenue from contracts with customers
Other									41,866
Total revenue unrelated to contracts with customers									41,866
Operating revenue, net	$ 296,767	$ 358,256	$ 299,261	$ 276,760	$ 277,985	$ 338,499	$ 308,661	$ 250,501	1,231,044
Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									896,927
Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									435,610
Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									288,791
Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									167,001
Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									15,582
Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									23,138
Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									209,918
Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									54,531
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									27,802
Affiliate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
CLECO POWER | Other
Total revenue from contracts with customers
Other miscellaneous fee revenue									18,200
CLECO POWER | Lost contribution to fixed cost
Total revenue from contracts with customers
Other									2,600
CLECO POWER | SSR | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									9,600
Operating Segments | CLECO POWER
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									1,199,730
Total revenue from contracts with customers
Other									41,866
Total revenue unrelated to contracts with customers									41,866
Operating revenue, net									1,241,596
Operating Segments | CLECO POWER | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									896,927
Operating Segments | CLECO POWER | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									435,610
Operating Segments | CLECO POWER | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									288,791
Operating Segments | CLECO POWER | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									167,001
Operating Segments | CLECO POWER | Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									15,582
Operating Segments | CLECO POWER | Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									23,138
Operating Segments | CLECO POWER | Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									219,598
Operating Segments | CLECO POWER | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									54,531
Operating Segments | CLECO POWER | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									27,800
Operating Segments | CLECO POWER | Affiliate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									874
OTHER
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									64,913
Total revenue from contracts with customers
Other									0
Total revenue unrelated to contracts with customers									0
Operating revenue, net									64,913
OTHER | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
OTHER | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
OTHER | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
OTHER | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
OTHER | Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
OTHER | Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
OTHER | Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(9,680)
OTHER | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
OTHER | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									2
OTHER | Affiliate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									74,591
ELIMINATIONS
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(75,465)
Total revenue from contracts with customers
Other									0
Total revenue unrelated to contracts with customers									0
Operating revenue, net									(75,465)
ELIMINATIONS | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Commercial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Other retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Surcharge
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Wholesale, net
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Transmission
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									0
ELIMINATIONS | Affiliate
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers									(75,465)
Price Risk Derivative | CLECO POWER | Other
Total revenue from contracts with customers
Other									$ 39,300