Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 12, 2016	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Uncollectible Accounts | CLECO POWER
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD	$ 2,674		$ 1,457	$ 7,199	$ 2,674
ADDITIONS CHARGED TO COSTS AND EXPENSES			977	4,179	5,511
UNCOLLECTIBLE ACCOUNT WRITE OFFS LESS RECOVERIES			1,620	9,921	986
BALANCE AT END OF PERIOD		$ 7,199	814	1,457	7,199
Unrestricted Storm Reserve | CLECO POWER
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD	2,801		4,186	2,607	2,801
ADDITIONS			0	4,000	71
DEDUCTIONS			514	2,421	265
BALANCE AT END OF PERIOD		2,607	3,672	4,186	2,607
Restricted Storm Reserve | CLECO POWER
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD	16,177		14,469	17,385	16,177
ADDITIONS			1,016	1,084	1,208
DEDUCTIONS			0	4,000	0
BALANCE AT END OF PERIOD		17,385	15,485	14,469	17,385
SUCCESSOR | Allowance for Uncollectible Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD		3,336	1,457	7,199
ADDITIONS CHARGED TO COSTS AND EXPENSES		4,348	977	4,179
UNCOLLECTIBLE ACCOUNT WRITE OFFS LESS RECOVERIES		485	1,620	9,921
BALANCE AT END OF PERIOD	3,336	7,199	814	1,457	7,199
SUCCESSOR | Unrestricted Storm Reserve
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD		2,536	4,186	2,607
ADDITIONS		71	0	4,000
DEDUCTIONS		0	514	2,421
BALANCE AT END OF PERIOD	2,536	2,607	3,672	4,186	2,607
SUCCESSOR | Restricted Storm Reserve
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD		16,515	14,469	17,385
ADDITIONS		870	1,016	1,084
DEDUCTIONS		0	0	4,000
BALANCE AT END OF PERIOD	16,515	17,385	$ 15,485	$ 14,469	17,385
PREDECESSOR | Allowance for Uncollectible Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD	2,674	3,336			2,674
ADDITIONS CHARGED TO COSTS AND EXPENSES	1,163
UNCOLLECTIBLE ACCOUNT WRITE OFFS LESS RECOVERIES	501
BALANCE AT END OF PERIOD	3,336
PREDECESSOR | Unrestricted Storm Reserve
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD	2,801	2,536			2,801
ADDITIONS	0
DEDUCTIONS	265
BALANCE AT END OF PERIOD	2,536
PREDECESSOR | Restricted Storm Reserve
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
BALANCE AT BEGINNING OF PERIOD	16,177	$ 16,515			$ 16,177
ADDITIONS	338
DEDUCTIONS	0
BALANCE AT END OF PERIOD	$ 16,515