Schedule I Financial Statements of Cleco Holdings (Parent Company Only) - Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended									9 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	Apr. 12, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)	$ 10,377	$ 47,360	$ 25,839	$ 10,861	$ 61,040	$ 45,304	$ 25,444	$ 6,292
SUCCESSOR
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)										$ (24,113)	$ (24,113)	$ 94,437	$ 138,080
Other comprehensive income (loss), net of tax
Postretirement benefits gain (loss), net of tax expense (benefit)											1,500	5,296	(4,421)
Amortization of interest rate derivatives to earnings (net of tax expense)											0	0	0
Total other comprehensive income (loss), net of tax										$ 1,500	1,500	5,296	(4,421)
Comprehensive income (loss), net of tax											(22,613)	99,733	133,659
SUCCESSOR | Cleco Holdings
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)											(24,113)	94,437	138,080
Other comprehensive income (loss), net of tax
Postretirement benefits gain (loss), net of tax expense (benefit)											1,500	5,296	(4,421)
Amortization of interest rate derivatives to earnings (net of tax expense)											0	0	0
Total other comprehensive income (loss), net of tax											1,500	5,296	(4,421)
Comprehensive income (loss), net of tax											$ (22,613)	$ 99,733	$ 133,659
PREDECESSOR
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)									$ (3,960)
Other comprehensive income (loss), net of tax
Postretirement benefits gain (loss), net of tax expense (benefit)									587
Amortization of interest rate derivatives to earnings (net of tax expense)									60
Total other comprehensive income (loss), net of tax									647
Comprehensive income (loss), net of tax									(3,313)
PREDECESSOR | Cleco Holdings
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)									(3,960)
Other comprehensive income (loss), net of tax
Postretirement benefits gain (loss), net of tax expense (benefit)									587
Amortization of interest rate derivatives to earnings (net of tax expense)									60
Total other comprehensive income (loss), net of tax									647
Comprehensive income (loss), net of tax									$ (3,313)