Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Apr. 12, 2016	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net (loss) income	$ 45,304	$ 39,621			$ 77,041
Other comprehensive (loss) income, net of tax [Abstract]
Postretirement benefits (loss) gain, net of tax	(44)	(2,305)
Total other comprehensive (loss) income, net of tax	(44)	(2,305)			(2,175)
Comprehensive (loss) income, net of tax	45,260	37,316
Successor
Net (loss) income				$ (42,294)	77,041
Other comprehensive (loss) income, net of tax [Abstract]
Postretirement benefits (loss) gain, net of tax				(2,305)	(2,175)
Amortization of interest rate derivatives to earnings, net of tax				0	0
Total other comprehensive (loss) income, net of tax				(2,305)	(2,175)
Comprehensive (loss) income, net of tax				$ (44,599)	74,866
Predecessor
Net (loss) income			$ (3,960)
Other comprehensive (loss) income, net of tax [Abstract]
Postretirement benefits (loss) gain, net of tax			587
Amortization of interest rate derivatives to earnings, net of tax			60
Total other comprehensive (loss) income, net of tax			647
Comprehensive (loss) income, net of tax			$ (3,313)
Cleco Power [Member]
Net (loss) income	54,852	52,572			108,439	$ 12,222
Other comprehensive (loss) income, net of tax [Abstract]
Postretirement benefits (loss) gain, net of tax	167	2,180			(60)	2,561
Amortization of interest rate derivatives to earnings, net of tax	53	53			159	159
Total other comprehensive (loss) income, net of tax	220	2,233			99	2,720
Comprehensive (loss) income, net of tax	$ 55,072	$ 54,805			$ 108,538	$ 14,942