Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities [Abstract]
Net (loss) income	$ 6,292
Financing activities [Abstract]
Cash and cash equivalents at beginning of period	23,077
Cash and cash equivalents at end of period	21,519
Predecessor [Member]
Operating activities [Abstract]
Net (loss) income		$ 19,368
Adjustments to reconcile net income (loss) to net cash provided by operating activities [Abstract]
Depreciation and amortization		40,285
Gain on sale of asset		(1,095)
Allowance for equity funds used during construction		(652)
Deferred income taxes		8,770
Deferred fuel costs		719
Cash surrender value of company-/trust-owned life insurance		(484)
Changes in assets and liabilities [Abstract]
Accounts receivable		3,129
Unbilled revenue		1,207
Fuel inventory and materials and supplies		17,725
Prepayments		2,076
Accounts payable		(21,379)
Customer deposits		2,877
Provision for merger commitments		0
Postretirement benefit obligations		2,630
Regulatory assets and liabilities, net		4,582
Other deferred accounts		5,529
Taxes accrued		12,651
Interest accrued		16,037
Other operating		2,257
Net cash provided by operating activities		116,232
Investing activities [Abstract]
Additions to property, plant, and equipment		(35,476)
Allowance for equity funds used during construction		652
Proceeds from sale of property		1,909
Contributions to equity investment in investee		(2,450)
Transfer of cash (to) from restricted accounts, net		4,088
Other investing		43
Net cash used in investing activities		(31,234)
Financing activities [Abstract]
Draws on credit facilities		3,000
Payments on credit facilities		(10,000)
Repayment of long-term debt		(8,546)
Dividends paid on common stock		(24,579)
Distributions to parent		0
Other financing		(673)
Net cash provided by (used in) financing activities		(40,798)
Net (decrease) increase in cash and cash equivalents		44,200
Cash and cash equivalents at beginning of period		68,246
Cash and cash equivalents at end of period		112,446
Supplementary cash flow information [Abstract]
Interest paid, net of amount capitalized		2,460
Income taxes paid (refunded), net		(481)
Supplementary non-cash investing and financing activities [Abstract]
Accrued additions to property, plant, and equipment		11,874
Successor [Member]
Operating activities [Abstract]
Net (loss) income	6,292
Adjustments to reconcile net income (loss) to net cash provided by operating activities [Abstract]
Depreciation and amortization	46,727
Gain on sale of asset	0
Allowance for equity funds used during construction	(911)
Deferred income taxes	3,041
Deferred fuel costs	(2,982)
Cash surrender value of company-/trust-owned life insurance	(1,702)
Changes in assets and liabilities [Abstract]
Accounts receivable	8,346
Unbilled revenue	4,765
Fuel inventory and materials and supplies	(7,733)
Prepayments	1,318
Accounts payable	(27,148)
Customer deposits	2,622
Provision for merger commitments	(3,866)
Postretirement benefit obligations	1,213
Regulatory assets and liabilities, net	2,599
Other deferred accounts	1,920
Taxes accrued	12,568
Interest accrued	25,620
Other operating	2,093
Net cash provided by operating activities	74,782
Investing activities [Abstract]
Additions to property, plant, and equipment	(47,890)
Allowance for equity funds used during construction	911
Proceeds from sale of property	242
Contributions to equity investment in investee	0
Transfer of cash (to) from restricted accounts, net	8,790
Other investing	(165)
Net cash used in investing activities	(38,112)
Financing activities [Abstract]
Draws on credit facilities	0
Payments on credit facilities	0
Repayment of long-term debt	(9,060)
Dividends paid on common stock	0
Distributions to parent	(28,955)
Other financing	(213)
Net cash provided by (used in) financing activities	(38,228)
Net (decrease) increase in cash and cash equivalents	(1,558)
Cash and cash equivalents at beginning of period	23,077
Cash and cash equivalents at end of period	21,519
Supplementary cash flow information [Abstract]
Interest paid, net of amount capitalized	4,011
Income taxes paid (refunded), net	1
Supplementary non-cash investing and financing activities [Abstract]
Accrued additions to property, plant, and equipment	27,617
Cleco Power [Member]
Operating activities [Abstract]
Net (loss) income	17,854	20,879
Adjustments to reconcile net income (loss) to net cash provided by operating activities [Abstract]
Depreciation and amortization	40,871	39,774
Gain on sale of asset	0	(1,095)
Allowance for equity funds used during construction	(911)	(652)
Deferred income taxes	10,135	1,854
Deferred fuel costs	(2,982)	719
Changes in assets and liabilities [Abstract]
Accounts receivable	8,064	3,130
Accounts and notes receivable, affiliate	471	1,716
Unbilled revenue	4,765	1,207
Fuel inventory and materials and supplies	(7,733)	17,725
Prepayments	925	1,560
Accounts payable	(23,836)	(20,581)
Accounts and notes payable, affiliate	2,083	731
Customer deposits	2,622	2,877
Provision for merger commitments	(3,866)	0
Postretirement benefit obligations	1,026	1,189
Regulatory assets and liabilities, net	2,103	4,582
Other deferred accounts	1,494	5,529
Taxes accrued	11,769	10,859
Interest accrued	14,230	16,078
Other operating	2,095	2,176
Net cash provided by operating activities	81,179	110,257
Investing activities [Abstract]
Additions to property, plant, and equipment	(46,744)	(35,453)
Allowance for equity funds used during construction	911	652
Proceeds from sale of property	242	1,909
Contributions to equity investment in investee	0	(2,450)
Transfer of cash (to) from restricted accounts, net	8,790	4,088
Other investing	39	43
Net cash used in investing activities	(36,762)	(31,211)
Financing activities [Abstract]
Repayment of long-term debt	(9,060)	(8,546)
Distributions to parent	(35,000)	(25,000)
Other financing	(675)	(657)
Net cash provided by (used in) financing activities	(44,735)	(34,203)
Net (decrease) increase in cash and cash equivalents	(318)	44,843
Cash and cash equivalents at beginning of period	21,482	65,705
Cash and cash equivalents at end of period	21,164	110,548
Supplementary cash flow information [Abstract]
Interest paid, net of amount capitalized	2,212	2,334
Income taxes paid (refunded), net	0	(485)
Supplementary non-cash investing and financing activities [Abstract]
Accrued additions to property, plant, and equipment	$ 27,493	$ 11,849