Consolidated Balance Sheets - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Current assets [Abstract]
Cash and cash equivalents	$ 6,127,000	$ 23,077,000
Restricted cash and cash equivalents	8,874,000	23,084,000
Customer accounts receivable (less allowance for doubtful accounts)	78,313,000	56,780,000
Other accounts receivable	33,934,000	19,778,000
Unbilled revenue	38,912,000	34,268,000
Fuel inventory, at average cost	51,847,000	46,410,000
Materials and supplies, at average cost	84,522,000	81,818,000
Energy risk management assets	13,425,000	7,884,000
Accumulated deferred fuel	21,057,000	20,787,000
Cash surrender value of company-/trust-owned life insurance policies	81,165,000	77,225,000
Prepayments	6,553,000	7,813,000
Regulatory assets	27,636,000	26,803,000
Other current assets	410,000	1,315,000
Total current assets	452,775,000	427,042,000
Property, plant, and equipment [Abstract]
Property, plant, and equipment	3,556,775,000	3,476,581,000
Accumulated depreciation	(162,040,000)	(75,816,000)
Net property, plant, and equipment	3,394,735,000	3,400,765,000
Construction work in progress	163,423,000	78,577,000
Total property, plant, and equipment, net	3,558,158,000	3,479,342,000
Equity investment in investees	18,172,000	18,672,000
Goodwill	1,490,797,000	1,490,797,000
Prepayments	1,887,000	4,731,000
Restricted cash and cash equivalents	24,547,000	23,410,000
Regulatory assets - deferred taxes, net	240,431,000	237,449,000
Regulatory assets	430,893,000	454,644,000
Net investment in direct financing lease	13,381,000	13,420,000
Intangible assets	121,269,000	142,634,000
Tax credit fund investment, net	10,409,000	11,888,000
Other deferred charges	34,982,000	39,115,000
Total assets	6,397,701,000	6,343,144,000
Current liabilities [Abstract]
Short-term debt	6,470,000	0
Long-term debt due within one year	19,193,000	19,715,000
Accounts payable	99,138,000	112,087,000
Customer deposits	58,018,000	56,599,000
Provision for rate refund	3,734,000	3,974,000
Provision for merger commitments	4,945,000	14,371,000
Taxes payable, net	26,894,000	3,942,000
Interest accrued	38,656,000	14,783,000
Energy risk management liabilities	538,000	201,000
Deferred compensation	11,604,000	11,654,000
Other current liabilities	21,309,000	14,850,000
Total current liabilities	290,499,000	252,176,000
Long-term liabilities and deferred credits [Abstract]
Accumulated deferred federal and state income taxes, net	1,075,869,000	1,033,055,000
Accumulated deferred investment tax credits	2,254,000	2,751,000
Postretirement benefit obligations	230,203,000	223,003,000
Restricted storm reserve	18,189,000	17,385,000
Other deferred credits	29,430,000	29,440,000
Total long-term liabilities and deferred credits	1,355,945,000	1,305,634,000
Long-term debt, net	2,713,583,000	2,738,571,000
Total liabilities	4,360,027,000	4,296,381,000
Commitments and Contingencies (Note 12)
Member's equity [Abstract]
Membership interest	1,985,421,000	2,069,376,000
Retained earnings/Accumulated deficit	52,928,000	(24,113,000)
Accumulated other comprehensive (loss) income	(675,000)	1,500,000
Total member’s equity	2,037,674,000	2,046,763,000
Total liabilities and member’s equity	6,397,701,000	6,343,144,000
Cleco Power [Member]
Current assets [Abstract]
Cash and cash equivalents	4,227,000	21,482,000
Restricted cash and cash equivalents	8,874,000	23,084,000
Customer accounts receivable (less allowance for doubtful accounts)	78,313,000	56,780,000
Accounts receivable - affiliate	1,545,000	1,406,000
Other accounts receivable	33,676,000	19,457,000
Taxes receivable, net	0	12,490,000
Unbilled revenue	38,912,000	34,268,000
Fuel inventory, at average cost	51,847,000	46,410,000
Materials and supplies, at average cost	84,522,000	81,818,000
Energy risk management assets	13,425,000	7,884,000
Accumulated deferred fuel	21,057,000	20,787,000
Cash surrender value of company-/trust-owned life insurance policies	20,216,000	20,018,000
Prepayments	5,367,000	5,892,000
Regulatory assets	18,779,000	17,721,000
Other current assets	0	577,000
Total current assets	380,760,000	370,074,000
Property, plant, and equipment [Abstract]
Property, plant, and equipment	4,858,764,000	4,790,565,000
Accumulated depreciation	(1,687,337,000)	(1,618,241,000)
Net property, plant, and equipment	3,171,427,000	3,172,324,000
Construction work in progress	162,500,000	77,306,000
Total property, plant, and equipment, net	3,333,927,000	3,249,630,000
Equity investment in investees	18,172,000	18,672,000
Prepayments	1,887,000	4,731,000
Restricted cash and cash equivalents	24,526,000	23,389,000
Regulatory assets - deferred taxes, net	240,431,000	237,449,000
Regulatory assets	253,146,000	268,016,000
Intangible assets	45,636,000	58,473,000
Other deferred charges	33,020,000	37,014,000
Total assets	4,331,505,000	4,267,448,000
Current liabilities [Abstract]
Short-term debt	6,470,000	0
Long-term debt due within one year	19,193,000	19,715,000
Accounts payable	92,522,000	101,874,000
Accounts payable - affiliate	8,293,000	7,190,000
Customer deposits	58,018,000	56,599,000
Provision for rate refund	3,734,000	3,974,000
Provision for merger commitments	4,945,000	14,371,000
Taxes payable, net	19,487,000	0
Interest accrued	20,348,000	7,141,000
Energy risk management liabilities	538,000	201,000
Other current liabilities	15,659,000	9,951,000
Total current liabilities	249,207,000	221,016,000
Long-term liabilities and deferred credits [Abstract]
Accumulated deferred federal and state income taxes, net	1,084,482,000	1,068,592,000
Accumulated deferred investment tax credits	2,254,000	2,751,000
Postretirement benefit obligations	164,183,000	159,107,000
Restricted storm reserve	18,189,000	17,385,000
Other deferred credits	27,483,000	28,339,000
Total long-term liabilities and deferred credits	1,296,591,000	1,276,174,000
Long-term debt, net	1,216,967,000	1,235,056,000
Total capitalization	2,785,707,000	2,770,258,000
Commitments and Contingencies (Note 12)
Member's equity [Abstract]
Total member’s equity	1,568,740,000	1,535,202,000
Total liabilities and member’s equity	$ 4,331,505,000	$ 4,267,448,000