Recent Authoritative Guidance - ASU 2017-07 (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations expenses	$ 30,511	$ 26,235	$ 58,477	$ 55,561
Total operating expenses	235,552	235,391	467,577	444,429
Operating income	63,709	73,270	108,444	114,733
Other expense	(3,745)	(3,281)	(6,928)	(6,219)
Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations expenses				55,561
Total operating expenses		235,391		444,429
Operating income		73,270		114,733
Other expense		(3,281)		(6,219)
Payments for merger related costs				100
Accounting Standards Update 2017-07 | AS REPORTED
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations expenses		29,256		61,244
Total operating expenses		238,412		450,114
Operating income		70,249		109,048
Other expense		(260)		(534)
CLECO POWER
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations expenses	26,812	27,649	54,116	57,913
Total operating expenses	229,299	234,120	458,163	441,397
Operating income	72,602	76,667	123,125	123,092
Other expense	$ (3,099)	(2,393)	$ (5,708)	(4,391)
CLECO POWER | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations expenses		27,649		57,913
Total operating expenses		234,120		441,397
Operating income		76,667		123,092
Other expense		(2,393)		(4,391)
CLECO POWER | Accounting Standards Update 2017-07 | AS REPORTED
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other operations expenses		29,782		61,770
Total operating expenses		236,253		445,254
Operating income		74,534		119,235
Other expense		$ (260)		$ (534)