Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
	Apr. 12, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2016	Apr. 12, 2016	Jun. 30, 2017	Jun. 30, 2016	Apr. 13, 2016
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period						$ 2,046,763
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax						(2,131)
Balances, end of period		$ 2,020,713				2,020,713
Balances		2,020,713				2,046,763
Total AOCI [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period						1,500
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax						(2,131)
Balances, end of period		(631)				(631)
Balances		(631)				1,500
Cleco Power
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period						1,535,202
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax		246	$ 234			(121)	$ 487
Balances, end of period		1,528,668				1,528,668
Balances		1,528,668				1,535,202
Cleco Power | Total AOCI [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period	$ (16,839)	(13,789)	(16,839)		$ (17,092)	(13,422)	(17,092)
Net current-period other comprehensive income [Abstract]
Postretirement benefit adjustments during the period		0				(584)
Amounts reclassified from accumulated other comprehensive income, net of tax		193	181			357	381
Total other comprehensive (loss) income, net of tax		246	234			(121)	487
Balances, end of period		(13,543)	(16,605)	$ (16,605)		(13,543)	(16,605)
Balances	(16,839)	(13,789)	(16,839)	(16,605)	(17,092)	(13,422)	(17,092)
Cleco Power | Total AOCI [Member] | Interest Expense [Member]
Net current-period other comprehensive income [Abstract]
Amounts reclassified from accumulated other comprehensive income, net of tax		53	53			106	106
Cleco Power | Postretirement Benefit Net Loss [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period	(11,164)	(8,325)	(11,164)		(11,364)	(7,905)	(11,364)
Net current-period other comprehensive income [Abstract]
Postretirement benefit adjustments during the period		0				(584)
Amounts reclassified from accumulated other comprehensive income, net of tax		193	181			357	381
Total other comprehensive (loss) income, net of tax		193	181			(227)	381
Balances, end of period		(8,132)	(10,983)	(10,983)		(8,132)	(10,983)
Balances	(11,164)	(8,325)	(11,164)	(10,983)	(11,364)	(7,905)	(11,364)
Cleco Power | Net Loss on Cash Flow Hedges [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period	(5,675)	(5,464)	(5,675)		(5,728)	(5,517)	(5,728)
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax		53	53			106	106
Balances, end of period		(5,411)	(5,622)	(5,622)		(5,411)	(5,622)
Balances	(5,675)	(5,464)	(5,675)	(5,622)	(5,728)	(5,517)	(5,728)
Cleco Power | Net Loss on Cash Flow Hedges [Member] | Interest Expense [Member]
Net current-period other comprehensive income [Abstract]
Amounts reclassified from accumulated other comprehensive income, net of tax		53	53			106	106
Predecessor
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax	66				647
Predecessor | Total AOCI [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period	(26,004)		(26,004)	(25,938)	(26,585)		(26,585)
Net current-period other comprehensive income [Abstract]
Amounts reclassified from accumulated other comprehensive income, net of tax	59				587
Total other comprehensive (loss) income, net of tax	66				647
Balances, end of period	(25,938)				(25,938)
Predecessor | Total AOCI [Member] | Interest Expense [Member]
Net current-period other comprehensive income [Abstract]
Amounts reclassified from accumulated other comprehensive income, net of tax	7				60
Predecessor | Postretirement Benefit Net Loss [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period	(20,329)		(20,329)	(20,270)	(20,857)		(20,857)
Net current-period other comprehensive income [Abstract]
Amounts reclassified from accumulated other comprehensive income, net of tax	59				587
Total other comprehensive (loss) income, net of tax	59				587
Balances, end of period	(20,270)				(20,270)
Predecessor | Net Loss on Cash Flow Hedges [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period	(5,675)		(5,675)	(5,668)	(5,728)		(5,728)
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax	7				60
Balances, end of period	(5,668)				(5,668)
Predecessor | Net Loss on Cash Flow Hedges [Member] | Interest Expense [Member]
Net current-period other comprehensive income [Abstract]
Amounts reclassified from accumulated other comprehensive income, net of tax	$ 7				$ 60
Successor
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax		60		0		(2,131)
Successor | Total AOCI [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period		(691)				1,500
Net current-period other comprehensive income [Abstract]
Postretirement benefit adjustments during the period		0				(2,065)
Amounts reclassified from accumulated other comprehensive income, net of tax		60				(66)
Total other comprehensive (loss) income, net of tax		60				(2,131)
Balances, end of period		(631)	0	0		(631)	0
Balances		(691)	0	0		1,500	0	$ 0
Successor | Postretirement Benefit Net Loss [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period		(691)				1,500
Net current-period other comprehensive income [Abstract]
Postretirement benefit adjustments during the period		0				(2,065)
Amounts reclassified from accumulated other comprehensive income, net of tax		60				(66)
Total other comprehensive (loss) income, net of tax		60				(2,131)
Balances, end of period		(631)	0	0		(631)	0
Balances		(691)	0	0		1,500	0	0
Successor | Net Loss on Cash Flow Hedges [Member]
Accumulated other comprehensive loss [Roll Forward]
Balances, beginning of period		0				0
Net current-period other comprehensive income [Abstract]
Total other comprehensive (loss) income, net of tax		0				0
Balances, end of period		0	0	0		0	0
Balances		$ 0	$ 0	$ 0		$ 0	$ 0	$ 0