Debt - Total Indebtedness (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total Long-term debt and finance Leases, net	$ 3,064,679	$ 2,874,485
Finance lease, current liabilities	617
Unamortized debt issuance costs	(13,700)	(10,300)
CLECO POWER
Debt Instrument [Line Items]
Total Long-term debt and finance Leases, net	1,327,372	1,387,774
Total bonds	1,386,055	1,406,625
Barge lease obligations	15,861
Barge lease obligations		16,418
Gross amount of long-term debt and finance leases	1,401,916	1,423,043
Less: long-term debt due within one year	60,970	20,571
Finance lease, current liabilities	617
Less: finance leases classified as long-term debt due within one year		557
Unamortized debt discount	(5,368)	(5,695)
Unamortized debt issuance costs	(7,589)	(8,446)
Unamortized debt issuance costs	$ (7,400)	(8,300)
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	50,000
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 | Cleco Katrina/Rita’s storm recovery bonds, 5.61%, due 2023
Debt Instrument [Line Items]
Interest rate	5.61%
Total bonds	$ 11,055	31,625
Cleco Holdings
Debt Instrument [Line Items]
Unamortized debt issuance costs	(11,900)	(8,200)
Long-term debt due within one year	(64,398)	0
Unamortized debt issuance costs	(6,271)	(1,989)
Fair value adjustment	127,976	138,700
Deferred debt issuance costs eliminated as a result of the 2016 Merger	$ 5,600	6,300
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, 3.375%, due 2029
Debt Instrument [Line Items]
Interest rate	3.375%
Total bonds	$ 300,000	0
Cleco Holdings | Senior notes, 4.973%, due 2046
Debt Instrument [Line Items]
Interest rate	4.973%
Total bonds	$ 350,000	350,000
Cleco Holdings | Bank term loan, due 2021
Debt Instrument [Line Items]
Bank term loan, variable rate, due 2021	300,000	300,000
Cleco Holdings | Bank term loan, due 2021
Debt Instrument [Line Items]
Bank term loan, variable rate, due 2021	$ 30,000	$ 0