Disclosures about Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Apr. 13, 2016
Revenue
Electric operations	$ 386,388	$ 451,902	$ 1,019,501	$ 1,130,318
Other operations	47,597	49,780	137,407	131,544
Affiliate revenue	0	0	0	0
Electric customer credits	(16,534)	(13,711)	(34,126)	(31,832)
Operating revenue, net	417,451	487,971	1,122,782	1,230,030
Net income	60,297	55,565	109,793	120,868
Depreciation and amortization	56,109	60,295	172,502	167,779
Interest income	910	1,690	2,964	4,456
Interest charges	34,060	35,832	103,923	105,671
Federal and state income tax expense (benefit)	25,075	14,088	40,230	32,355
Other corporate costs and noncash items	(1,078)	2,411	6,807	4,406
EBITDA	173,553	166,501	430,291	426,623
Additions to property, plant, and equipment			215,692	251,845
Equity investment in investees	13,072		13,072		$ 17,072
Goodwill	1,490,797		1,490,797		1,490,797	$ 1,490,000
Total assets	8,098,074		8,098,074		7,476,298
CLECO POWER
Revenue
Electric operations	288,852	339,869	752,925	862,969
Other operations	17,775	18,485	49,443	53,318
Affiliate revenue	1,506	334	3,852	971
Electric customer credits	(16,534)	(13,711)	(33,974)	(30,565)
Operating revenue, net	291,599	344,977	772,246	886,693
Net income	36,092	51,527	76,156	127,595
Interest income	789	1,421	2,498	3,281
Interest charges	18,441	17,983	55,624	52,498
Federal and state income tax expense (benefit)	18,076	12,431	30,770	34,407
Additions to property, plant, and equipment			205,765	247,987
Equity investment in investees	13,072		13,072		17,072
Total assets	4,983,138		4,983,138		4,476,530
Power supply agreements
Revenue
Amortization of intangible assets	6,400	6,474	19,200	17,873
OPERATING SEGMENTS
Revenue
Electric operations	388,808	454,322	1,026,761	1,137,579
Other operations	49,106	52,222	142,371	136,937
Affiliate revenue	1,506	365	4,056	1,002
Electric customer credits	(16,534)	(13,711)	(34,127)	(31,832)
Operating revenue, net	422,886	493,198	1,139,061	1,243,686
Net income	74,449	74,333	160,811	174,383
Depreciation and amortization	51,612	55,783	158,926	154,289
Interest income	799	1,641	2,767	4,123
Interest charges	17,957	17,983	55,271	52,498
Federal and state income tax expense (benefit)	30,334	20,043	58,050	49,576
EBITDA	173,553	166,501	430,291	426,623
Additions to property, plant, and equipment			213,673	251,641
Equity investment in investees	13,072		13,072		17,072
Goodwill	1,490,797		1,490,797		1,490,797
Total assets	7,540,322		7,540,322		6,978,918
OPERATING SEGMENTS | CLECO POWER
Revenue
Electric operations	288,852	339,869	752,925	862,969
Other operations	17,775	18,485	49,443	53,318
Affiliate revenue	1,506	334	3,852	971
Electric customer credits	(16,534)	(13,711)	(33,974)	(30,565)
Operating revenue, net	291,599	344,977	772,246	886,693
Net income	36,092	51,527	76,156	127,595
Depreciation and amortization	40,268	44,903	125,541	126,610
Interest income	789	1,421	2,498	3,281
Interest charges	18,441	17,983	55,624	52,498
Federal and state income tax expense (benefit)	18,076	12,431	30,770	34,407
EBITDA	112,088	125,423	285,593	337,829
Additions to property, plant, and equipment			205,765	247,987
Equity investment in investees	13,072		13,072		17,072
Goodwill	1,490,797		1,490,797		1,490,797
Total assets	6,473,935		6,473,935		5,967,327
OPERATING SEGMENTS | CLECO CAJUN
Revenue
Electric operations	99,956	114,453	273,836	274,610
Other operations	31,331	33,737	92,928	83,619
Affiliate revenue	0	31	204	31
Electric customer credits	0	0	(153)	(1,267)
Operating revenue, net	131,287	148,221	366,815	356,993
Net income	38,357	22,806	84,655	46,788
Depreciation and amortization	11,344	10,880	33,385	27,679
Interest income	10	220	269	842
Interest charges	(484)	0	(353)	0
Federal and state income tax expense (benefit)	12,258	7,612	27,280	15,169
EBITDA	61,465	41,078	144,698	88,794
Additions to property, plant, and equipment			7,908	3,654
Equity investment in investees	0		0		0
Goodwill	0		0		0
Total assets	1,066,387		1,066,387		1,011,591
Amortization of deferred lease income	(2,300)	(2,300)	(6,900)	(6,100)
OPERATING SEGMENTS | CLECO CAJUN | Power supply agreements
Revenue
Amortization of intangible assets and liabilities	3,100	3,200	9,300	8,300
OTHER
Revenue
Electric operations	(2,420)	(2,420)	(7,260)	(7,260)
Other operations	1	0	2	2
Affiliate revenue	35,522	28,252	93,938	77,800
Electric customer credits	0	0	0	0
Operating revenue, net	33,103	25,832	86,680	70,542
Net income	(14,154)	(18,768)	(51,019)	(53,515)
Depreciation and amortization	4,497	4,512	13,575	13,491
Interest income	121	228	276	841
Interest charges	16,115	18,028	48,731	53,682
Federal and state income tax expense (benefit)	(5,260)	(5,955)	(17,821)	(17,220)
Additions to property, plant, and equipment			2,019	204
Equity investment in investees	0		0		0
Goodwill	0		0		0
Total assets	606,687		606,687		546,096
OTHER | Power supply agreements | CLECO POWER
Revenue
Amortization of intangible assets	2,400	2,400	7,300	7,300
ELIMINATIONS
Revenue
Electric operations	0	0	0	(1)
Other operations	(1,510)	(2,442)	(4,966)	(5,395)
Affiliate revenue	(37,028)	(28,617)	(97,994)	(78,802)
Electric customer credits	0	0	1	0
Operating revenue, net	(38,538)	(31,059)	(102,959)	(84,198)
Net income	2	0	1	0
Depreciation and amortization	0	0	1	(1)
Interest income	(10)	(179)	(79)	(508)
Interest charges	(12)	(179)	(79)	(509)
Federal and state income tax expense (benefit)	1	$ 0	1	(1)
Additions to property, plant, and equipment			0	$ 0
Equity investment in investees	0		0		0
Goodwill	0		0		0
Total assets	$ (48,935)		$ (48,935)		$ (48,716)