Debt - Total Indebtedness (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (10,300)	$ (11,600)
Total long-term debt and capital leases, net	2,874,485	2,836,105
CLECO POWER
Debt Instrument [Line Items]
Total bonds	1,406,625	1,375,819
Barge lease obligations	16,418	0
Gross amount of long-term debt	1,423,043	1,375,819
Less: long-term debt due within one year	20,571	19,193
Less: capital lease obligations classified as long-term debt due within one year	557	0
Unamortized debt discount	(5,695)	(6,010)
Unamortized debt issuance costs	(8,446)	(9,141)
Unamortized debt issuance costs	(8,300)	(9,100)
Total long-term debt and capital leases, net	$ 1,387,774	1,341,475
CLECO POWER | Senior notes, 2.94%, due 2022
Debt Instrument [Line Items]
Interest rate	2.94%
Total bonds	$ 25,000	25,000
CLECO POWER | Senior notes, 3.08%, due 2023
Debt Instrument [Line Items]
Interest rate	3.08%
Total bonds	$ 100,000	100,000
CLECO POWER | Senior notes, 3.17%, due 2024
Debt Instrument [Line Items]
Interest rate	3.17%
Total bonds	$ 50,000	0
CLECO POWER | Senior notes, 3.68%, due 2025
Debt Instrument [Line Items]
Interest rate	3.68%
Total bonds	$ 75,000	75,000
CLECO POWER | Senior notes, 3.47%, due 2026
Debt Instrument [Line Items]
Interest rate	3.47%
Total bonds	$ 130,000	130,000
CLECO POWER | Senior notes, 4.33%, due 2027
Debt Instrument [Line Items]
Interest rate	4.33%
Total bonds	$ 50,000	50,000
CLECO POWER | Senior notes, 3.57%, due 2028
Debt Instrument [Line Items]
Interest rate	3.57%
Total bonds	$ 200,000	200,000
CLECO POWER | Senior notes, 6.50%, due 2035
Debt Instrument [Line Items]
Interest rate	6.50%
Total bonds	$ 295,000	295,000
CLECO POWER | Senior notes, 6.00%, due 2040
Debt Instrument [Line Items]
Interest rate	6.00%
Total bonds	$ 250,000	250,000
CLECO POWER | Senior notes, 5.12%, due 2041
Debt Instrument [Line Items]
Interest rate	5.12%
Total bonds	$ 100,000	100,000
CLECO POWER | Series A GO Zone bonds, 2.00%, due 2038, mandatory tender in 2020
Debt Instrument [Line Items]
Interest rate	2.00%
Total bonds	$ 50,000	50,000
CLECO POWER | Series B GO Zone bonds, 4.25%, due 2038
Debt Instrument [Line Items]
Interest rate	4.25%
Total bonds	$ 50,000	50,000
CLECO POWER | Solid waste disposal facility bonds, 4.70%, due 2036, callable November 1, 2016
Debt Instrument [Line Items]
Interest rate	4.70%
CLECO POWER | Cleco Katrina/Rita’s storm recovery bonds, 4.41%, due 2020
Debt Instrument [Line Items]
Interest rate	4.41%
CLECO POWER | Cleco Katrina/Rita’s storm recovery bonds, 5.61%, due 2023
Debt Instrument [Line Items]
Interest rate	5.61%
Total bonds	$ 31,625	50,819
Cleco Holdings
Debt Instrument [Line Items]
Unamortized debt issuance costs	(8,200)	(9,200)
Unamortized debt issuance costs	(1,989)	(2,516)
Fair value adjustment	138,700	147,146
Deferred debt issuance costs eliminated as a result of the 2016 Merger	$ 6,300	6,700
Cleco Holdings | Senior notes, 3.250%, due 2023
Debt Instrument [Line Items]
Interest rate	3.25%
Total bonds	$ 165,000	165,000
Cleco Holdings | Senior notes, 3.743%, due 2026
Debt Instrument [Line Items]
Interest rate	3.743%
Total bonds	$ 535,000	535,000
Cleco Holdings | Senior notes, 4.973%, due 2046
Debt Instrument [Line Items]
Interest rate	4.973%
Total bonds	$ 350,000	350,000
Cleco Holdings | Senior notes, 4.973%, due 2046
Debt Instrument [Line Items]
Bank term loan, variable rate, due 2021	$ 300,000	$ 300,000