Disclosures about Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Revenue
Electric operations	$ 351,936	$ 321,956	$ 718,181	$ 633,113
Other operations	45,330	44,902	95,056	89,810
Affiliate revenue	0	0	0	0
Electric customer credits	(18,517)	(9,100)	(39,494)	(17,593)
Operating revenue, net	378,749	357,758	773,743	705,330
Net income	78,822	43,168	99,149	49,496
Depreciation and amortization	57,699	57,304	115,862	116,393
Interest income	829	898	1,475	2,054
Interest charges	33,291	34,715	67,183	69,863
Federal and state income tax (benefit)	9,837	13,593	416	15,155
Other corporate costs and noncash items	(1,385)	(4,326)	(4,331)	7,887
EBITDA	177,435	143,556	276,804	256,740
Additions to property, plant, and equipment			140,507	139,339
Equity investment in investees	5,572		5,572		$ 9,072
Goodwill	1,490,797		1,490,797		1,490,797
Total assets	7,941,469		7,941,469		7,725,569
CLECO POWER
Revenue
Electric operations	262,948	239,643	530,107	464,073
Other operations	16,269	15,904	34,895	31,668
Affiliate revenue	1,224	1,240	2,879	2,346
Electric customer credits	(18,762)	(9,100)	(39,738)	(17,440)
Operating revenue, net	261,679	247,687	528,143	480,647
Net income	27,421	28,233	45,846	40,064
Interest income	825	755	1,468	1,709
Interest charges	18,237	18,603	36,883	37,184
Federal and state income tax (benefit)	8,956	9,356	(767)	12,694
Additions to property, plant, and equipment			134,185	132,578
Equity investment in investees	5,572		5,572		9,072
Total assets	4,947,421		4,947,421		4,766,147
Power supply agreements
Revenue
Amortization of intangible assets	6,400	6,400	12,800	12,800
OPERATING SEGMENTS
Revenue
Electric operations	354,355	324,376	723,021	637,953
Other operations	46,924	46,540	98,589	93,265
Affiliate revenue	1,224	1,283	2,879	2,550
Electric customer credits	(18,518)	(9,100)	(39,494)	(17,593)
Operating revenue, net	383,985	363,099	784,995	716,175
Net income	79,915	54,995	112,821	86,362
Depreciation and amortization	53,272	52,739	107,000	107,314
Interest income	828	858	1,474	1,967
Interest charges	18,057	18,723	36,551	37,315
Federal and state income tax (benefit)	27,019	17,957	21,906	27,716
EBITDA	177,435	143,556	276,804	256,740
Additions to property, plant, and equipment			139,067	137,995
Equity investment in investees	5,572		5,572		9,072
Goodwill	1,490,797		1,490,797		1,490,797
Total assets	7,516,752		7,516,752		7,286,756
OPERATING SEGMENTS | CLECO POWER
Revenue
Electric operations	262,948	239,643	530,107	464,073
Other operations	16,269	15,904	34,895	31,668
Affiliate revenue	1,224	1,240	2,879	2,346
Electric customer credits	(18,762)	(9,100)	(39,738)	(17,440)
Operating revenue, net	261,679	247,687	528,143	480,647
Net income	27,421	28,233	45,846	40,064
Depreciation and amortization	40,933	41,596	83,009	85,273
Interest income	825	755	1,468	1,709
Interest charges	18,237	18,603	36,883	37,184
Federal and state income tax (benefit)	8,956	9,356	(767)	12,694
EBITDA	94,722	97,033	163,503	173,506
Additions to property, plant, and equipment			134,185	132,578
Equity investment in investees	5,572		5,572		9,072
Goodwill	1,490,797		1,490,797		1,490,797
Total assets	6,438,218		6,438,218		6,256,944
OPERATING SEGMENTS | CLECO CAJUN
Revenue
Electric operations	91,407	84,733	192,914	173,880
Other operations	30,655	30,636	63,694	61,597
Affiliate revenue	0	43	0	204
Electric customer credits	244	0	244	(153)
Operating revenue, net	122,306	115,412	256,852	235,528
Net income	52,494	26,762	66,975	46,298
Depreciation and amortization	12,339	11,143	23,991	22,041
Interest income	3	103	6	258
Interest charges	(180)	120	(332)	131
Federal and state income tax (benefit)	18,063	8,601	22,673	15,022
EBITDA	82,713	46,523	113,301	83,234
Additions to property, plant, and equipment			4,882	5,417
Equity investment in investees	0		0		0
Goodwill	0		0		0
Total assets	1,078,534		1,078,534		1,029,812
Amortization of deferred lease income	(2,300)	(2,300)	(4,600)	(4,600)
OPERATING SEGMENTS | CLECO CAJUN | Power supply agreements
Revenue
Amortization of intangible assets and liabilities	3,300	3,100	6,400	6,200
OTHER
Revenue
Electric operations	(2,420)	(2,420)	(4,840)	(4,840)
Other operations	1	1	2	1
Affiliate revenue	26,120	29,138	53,276	58,415
Electric customer credits	0	0	0	0
Operating revenue, net	23,701	26,719	48,438	53,576
Net income	(1,093)	(11,826)	(13,672)	(36,865)
Depreciation and amortization	4,427	4,565	8,862	9,079
Interest income	14	55	57	155
Interest charges	15,248	16,007	30,687	32,617
Federal and state income tax (benefit)	(17,182)	(4,364)	(21,490)	(12,561)
Additions to property, plant, and equipment			1,440	1,344
Equity investment in investees	0		0		0
Goodwill	0		0		0
Total assets	569,126		569,126		595,217
OTHER | Power supply agreements | CLECO POWER
Revenue
Amortization of intangible assets	2,400	2,400	4,800	4,800
ELIMINATIONS
Revenue
Electric operations	1	0	0	0
Other operations	(1,595)	(1,639)	(3,535)	(3,456)
Affiliate revenue	(27,344)	(30,421)	(56,155)	(60,965)
Electric customer credits	1	0	0	0
Operating revenue, net	(28,937)	(32,060)	(59,690)	(64,421)
Net income	0	(1)	0	(1)
Depreciation and amortization	0	0	0	0
Interest income	(13)	(15)	(56)	(68)
Interest charges	(14)	(15)	(55)	(69)
Federal and state income tax (benefit)	0	$ 0	0	0
Additions to property, plant, and equipment			0	$ 0
Equity investment in investees	0		0		0
Goodwill	0		0		0
Total assets	$ (144,409)		$ (144,409)		$ (156,404)