Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended				6 Months Ended		12 Months Ended
	Apr. 12, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2016	Apr. 12, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017
Operating activities [Abstract]
Net (loss) income						$ 31,736
Financing activities [Abstract]
Cash and cash equivalents at beginning of period						23,077
Cash and cash equivalents at end of period		$ 10,512				10,512		$ 10,512
Predecessor
Operating activities [Abstract]
Net (loss) income	$ (23,328)				$ (3,960)
Adjustments to reconcile net income (loss) to net cash provided by operating activities [Abstract]
Depreciation and amortization					45,869
Gain on sale of asset					(1,095)
Provision for doubtful accounts					1,212
Unearned compensation expense					3,276
Allowance for equity funds used during construction					(724)
Deferred income taxes					2,219
Deferred fuel costs					977
Cash surrender value of company-/trust-owned life insurance					(840)
Changes in assets and liabilities [Abstract]
Accounts receivable					(1,865)
Accounts and notes receivable, affiliate					0
Unbilled revenue					563
Fuel inventory and materials and supplies					19,312
Prepayments					2,395
Accounts payable					8,348
Customer deposits					3,342
Provision for merger commitments					0
Postretirement benefit obligations					9,746
Regulatory assets and liabilities, net					5,178
Other deferred accounts					6,878
Taxes accrued					10,820
Interest accrued					17,909
Deferred Compensation					(793)
Other operating					1,012
Net cash provided by operating activities					129,779
Investing activities [Abstract]
Additions to property, plant, and equipment					(42,392)
Allowance for equity funds used during construction					724
Proceeds from sale of property					1,932
Contributions to equity investment in investee					(2,450)
Transfer of cash (to) from restricted accounts, net					4,847
Other investing					529
Net cash used in investing activities					(36,810)
Financing activities [Abstract]
Draws on credit facilities					3,000
Payments on credit facilities					(10,000)
Issuance of Long-term Debt					0
Repayment of long-term debt					(8,546)
Payment of Financing Costs					(43)
Dividends paid on common stock					(24,579)
Contributions from Parent					0
Distributions to parent					0
Other financing					(717)
Net cash provided by (used in) financing activities					(40,885)
Net (decrease) increase in cash and cash equivalents					52,084
Cash and cash equivalents at beginning of period				$ 120,330	68,246		$ 68,246
Cash and cash equivalents at end of period	120,330				120,330
Supplementary cash flow information [Abstract]
Interest paid, net of amount capitalized					2,478
Income taxes paid (refunded), net					(481)
Supplementary non-cash investing and financing activities [Abstract]
Accrued additions to property, plant, and equipment					10,619
Non-cash additions to property, plant, and equipment					0
Successor
Operating activities [Abstract]
Net (loss) income		25,444		(81,914)		31,736
Adjustments to reconcile net income (loss) to net cash provided by operating activities [Abstract]
Depreciation and amortization				57,718		93,943
Gain on sale of asset				0		0
Provision for doubtful accounts				926		2,587
Unearned compensation expense				361		1,909
Allowance for equity funds used during construction				(748)		(2,350)
Deferred income taxes				(47,264)		16,881
Deferred fuel costs				(7,717)		(305)
Cash surrender value of company-/trust-owned life insurance				(1,761)		(2,393)
Changes in assets and liabilities [Abstract]
Accounts receivable				(5,360)		(30,205)
Accounts and notes receivable, affiliate				(3,786)		12
Unbilled revenue				(12,988)		(5,677)
Fuel inventory and materials and supplies				12,765		(9,652)
Prepayments				(2,425)		(896)
Accounts payable				(19,143)		(23,828)
Customer deposits				2,787		5,646
Provision for merger commitments				150,840		(6,761)
Postretirement benefit obligations				936		2,696
Regulatory assets and liabilities, net				4,104		4,896
Other deferred accounts				(7,109)		(8,631)
Taxes accrued				(8,161)		15,000
Interest accrued				(11,760)		965
Deferred Compensation				(1,436)		(581)
Other operating				1,925		2,073
Net cash provided by operating activities				20,790		87,065
Investing activities [Abstract]
Additions to property, plant, and equipment				(43,623)		(128,693)
Allowance for equity funds used during construction				748		2,350
Proceeds from sale of property				159		458
Contributions to equity investment in investee				0		0
Transfer of cash (to) from restricted accounts, net				(147,830)		6,003
Other investing				579		816
Net cash used in investing activities				(189,967)		(119,066)
Financing activities [Abstract]
Draws on credit facilities				15,000		114,000
Payments on credit facilities				(15,000)		(29,000)
Issuance of Long-term Debt				1,350,000		0
Repayment of long-term debt				(1,350,000)		(9,060)
Payment of Financing Costs				(5,830)		(301)
Dividends paid on common stock				(572)		0
Contributions from Parent				100,720		0
Distributions to parent				(28,000)		(55,655)
Other financing				(559)		(548)
Net cash provided by (used in) financing activities				65,759		19,436
Net (decrease) increase in cash and cash equivalents				(103,418)		(12,565)
Cash and cash equivalents at beginning of period				120,330		23,077		16,912
Cash and cash equivalents at end of period	$ 120,330	10,512	$ 16,912	16,912	120,330	10,512	16,912	10,512
Supplementary cash flow information [Abstract]
Interest paid, net of amount capitalized				37,466		57,937
Income taxes paid (refunded), net				256		1
Supplementary non-cash investing and financing activities [Abstract]
Accrued additions to property, plant, and equipment				19,668		13,125
Non-cash additions to property, plant, and equipment				0		3,009
Cleco Power
Operating activities [Abstract]
Net (loss) income		35,733	(61,229)			53,587	(40,350)
Adjustments to reconcile net income (loss) to net cash provided by operating activities [Abstract]
Depreciation and amortization						82,292	79,059
Gain on sale of asset						0	(1,095)
Provision for doubtful accounts						2,500	2,051
Unearned compensation expense						1,023	1,186
Allowance for equity funds used during construction						(2,350)	(1,472)
Deferred income taxes						3,916	(22,438)
Deferred fuel costs						(305)	(6,740)
Changes in assets and liabilities [Abstract]
Accounts receivable						(30,240)	(6,914)
Accounts and notes receivable, affiliate						1,560	(680)
Unbilled revenue						(5,677)	(12,425)
Fuel inventory and materials and supplies						(9,652)	32,077
Prepayments						(1,438)	(512)
Accounts payable						(21,455)	(13,238)
Accounts and notes payable, affiliate						(58)	(4,129)
Customer deposits						5,646	6,129
Provision for merger commitments						(6,761)	150,840
Postretirement benefit obligations						2,472	2,426
Regulatory assets and liabilities, net						3,902	8,854
Other deferred accounts						(8,665)	(231)
Taxes accrued						21,753	(11,129)
Interest accrued						1,037	1,102
Other operating						1,436	1,819
Net cash provided by operating activities						94,523	164,190
Investing activities [Abstract]
Additions to property, plant, and equipment						(127,297)	(85,936)
Allowance for equity funds used during construction						2,350	1,472
Proceeds from sale of property						458	2,091
Contributions to equity investment in investee						0	(2,450)
Transfer of cash (to) from restricted accounts, net						6,003	(142,983)
Other investing						605	157
Net cash used in investing activities						(117,881)	(227,649)
Financing activities [Abstract]
Draws on credit facilities						90,000	15,000
Payments on credit facilities						(15,000)	(15,000)
Repayment of long-term debt						(9,060)	(8,546)
Contributions from Parent						0	50,000
Distributions to parent						(60,000)	(35,000)
Other financing						(595)	(1,390)
Net cash provided by (used in) financing activities						5,345	5,064
Net (decrease) increase in cash and cash equivalents						(18,013)	(58,395)
Cash and cash equivalents at beginning of period					$ 65,705	21,482	65,705	7,310
Cash and cash equivalents at end of period		$ 3,469	$ 7,310	$ 7,310		3,469	7,310	$ 3,469
Supplementary cash flow information [Abstract]
Interest paid, net of amount capitalized						31,907	35,746
Income taxes paid (refunded), net						0	(485)
Supplementary non-cash investing and financing activities [Abstract]
Accrued additions to property, plant, and equipment						13,081	19,571
Non-cash additions to property, plant, and equipment						$ 3,009	$ 0