Schedule I Financial Statements of Cleco Corporation, Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended									9 Months Ended		12 Months Ended
	Apr. 12, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Apr. 12, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2015
Successor [Member]
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)		$ 61,040	$ 45,304	$ 25,444	$ 6,292	$ 18,180	$ 39,621	$ (81,914)			$ (24,113)	$ (24,113)	$ 138,080
Other comprehensive income (loss), net of tax:
Postretirement benefits gain (loss), net of tax												1,500	(4,421)
Amortization of interest rate derivatives to earnings (net of tax expense)												0	0
Total other comprehensive income (loss), net of tax											$ 1,500	1,500	(4,421)
Comprehensive income (loss), net of tax												(22,613)	133,659
Successor [Member] | Cleco Holdings [Member]
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)												(24,113)	138,080
Other comprehensive income (loss), net of tax:
Postretirement benefits gain (loss), net of tax												1,500	(4,421)
Amortization of interest rate derivatives to earnings (net of tax expense)												0	0
Total other comprehensive income (loss), net of tax												1,500	(4,421)
Comprehensive income (loss), net of tax												$ (22,613)	$ 133,659
Predecessor [Member]
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)	$ (23,328)								$ (3,960)	$ 19,368				$ 133,669
Other comprehensive income (loss), net of tax:
Postretirement benefits gain (loss), net of tax									587					5,869
Amortization of interest rate derivatives to earnings (net of tax expense)									60					211
Total other comprehensive income (loss), net of tax									647					6,080
Comprehensive income (loss), net of tax									(3,313)					139,749
Predecessor [Member] | Cleco Holdings [Member]
Condensed Statements of Comprehensive Income [Abstract]
Net income (loss)									(3,960)					133,669
Other comprehensive income (loss), net of tax:
Postretirement benefits gain (loss), net of tax									587					5,869
Amortization of interest rate derivatives to earnings (net of tax expense)									60					211
Total other comprehensive income (loss), net of tax									647					6,080
Comprehensive income (loss), net of tax									$ (3,313)					$ 139,749