Regulatory Assets and Liabilities - Narrative (Details)		1 Months Ended				3 Months Ended	12 Months Ended
	Apr. 13, 2016 instrument	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)	May 31, 2013 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2011 USD ($) treasury_rate_lock	Oct. 31, 2016 USD ($)	Feb. 28, 2016 USD ($)	Apr. 30, 2013 USD ($)	Feb. 28, 2011 USD ($)
Treasury Lock
Regulatory Assets and Liabilities [Line Items]
Number of instruments settled | instrument	2
Postretirement costs
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		$ 19,387,000	$ 21,375,000			$ 19,387,000	$ 19,387,000	$ 21,375,000
Financing costs
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		8,279,000	8,623,000			8,279,000	8,279,000	8,623,000
TCJA
Regulatory Assets and Liabilities [Line Items]
Amount recovered above the actual PPA capacity costs		375,000,000	348,600,000			375,000,000	375,000,000	348,600,000
Net retail portion of franchise taxes paid						26,400,000
CLECO POWER
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		275,172,000	273,220,000			275,172,000	275,172,000	273,220,000
Increase (decrease) in deferred fuel costs							$ 18,549,000	(11,909,000)	$ 7,215,000
CLECO POWER | Treasury Lock
Regulatory Assets and Liabilities [Line Items]
Number of treasury locks | treasury_rate_lock										2
Loss on settlements										$ 26,800,000
CLECO POWER | Interest Rate Swap
Regulatory Assets and Liabilities [Line Items]
Loss on settlements					$ 3,300,000
CLECO POWER | Mining costs
Regulatory Assets and Liabilities [Line Items]
Amortization period							11 years 6 months
Regulatory Assets		1,274,000	3,823,000			1,274,000	$ 1,274,000	3,823,000
CLECO POWER | Postretirement costs
Regulatory Assets and Liabilities [Line Items]
Amortization period							9 years
Regulatory Assets		140,245,000	142,764,000			140,245,000	$ 140,245,000	142,764,000
CLECO POWER | Tree trimming costs
Regulatory Assets and Liabilities [Line Items]
Amortization period							3 years 6 months
Anticipated removal costs							$ 20,800,000
Maximum amount of costs approved to defer											$ 10,900,000
Anticipated removal costs to be expensed							4,000,000
Anticipated amount of removal costs to be deferred and recovered							5,900,000
Regulatory Assets		9,069,000	7,193,000			9,069,000	$ 9,069,000	7,193,000
CLECO POWER | Training costs
Regulatory Assets and Liabilities [Line Items]
Amortization period							50 years
Regulatory Assets		6,396,000	6,552,000			6,396,000	$ 6,396,000	6,552,000
CLECO POWER | Surcredits, net
Regulatory Assets and Liabilities [Line Items]
Amortization period							4 years
Regulatory Assets		289,000	2,173,000			289,000	$ 289,000	2,173,000
CLECO POWER | AMI deferred revenue requirement
Regulatory Assets and Liabilities [Line Items]
Amortization period							11 years
Regulatory Assets		3,681,000	4,227,000			3,681,000	$ 3,681,000	4,227,000
CLECO POWER | AMI deferred revenue requirement | MAXIMUM
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets														$ 20,000,000
CLECO POWER | Emergency declarations
Regulatory Assets and Liabilities [Line Items]
Amortization period							3 years
Regulatory Assets		2,980,000	4,131,000			2,980,000	$ 2,980,000	4,131,000
CLECO POWER | Production O&M Expenses
Regulatory Assets and Liabilities [Line Items]
Amortization period							3 years
Retail jurisdictional portion		45,000,000				45,000,000	$ 45,000,000
Increase in other regulatory asset		8,000,000	400,000
CLECO POWER | Production O&M Expenses | MAXIMUM
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		23,000,000				23,000,000	$ 23,000,000
CLECO POWER | Acquisition costs or Transaction costs
Regulatory Assets and Liabilities [Line Items]
Amortization period							30 years
Regulatory Assets		2,230,000	2,336,000			2,230,000	$ 2,230,000	2,336,000
CLECO POWER | Acquisition costs or Transaction costs | Natural Gas Processing Plant
Regulatory Assets and Liabilities [Line Items]
Amortization period							35 years
Regulatory Assets		938,000	968,000			938,000	$ 938,000	968,000
CLECO POWER | Financing costs
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		7,923,000	8,293,000			7,923,000	$ 7,923,000	8,293,000
CLECO POWER | Financing costs | Treasury Lock
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets										$ 7,400,000
CLECO POWER | Financing costs | Interest Rate Swap
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets					$ 2,900,000
CLECO POWER | MISO integration costs
Regulatory Assets and Liabilities [Line Items]
Amortization period							4 years
CLECO POWER | MISO integration costs | Natural Gas Processing Plant
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		0	468,000			0	$ 0	468,000
CLECO POWER | Corporate franchise tax, net
Regulatory Assets and Liabilities [Line Items]
Amortization period							12 months
Regulatory Assets		1,416,000	153,000			1,416,000	$ 1,416,000	153,000
CLECO POWER | MATS Costs
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		0	2,564,000			0	$ 0	2,564,000				$ 7,100,000
CLECO POWER | Energy Efficiency
Regulatory Assets and Liabilities [Line Items]
Amortization period							4 years
Regulatory Assets		2,585,000	0			2,585,000	$ 2,585,000	0
CLECO POWER | Other
Regulatory Assets and Liabilities [Line Items]
Amortization period							3 years
Regulatory Assets		13,000	484,000			13,000	$ 13,000	484,000
CLECO POWER | Insurance deductible for flood damages
Regulatory Assets and Liabilities [Line Items]
Amortization period				12 months
Insurance recoveries				$ 900,000
CLECO POWER | Accumulated deferred fuel
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		20,112,000	13,980,000			20,112,000	$ 20,112,000	13,980,000
Percentage of total fuel cost regulated by the LPSC (in hundredths)							76.00%
Increase (decrease) in deferred fuel costs							$ 6,100,000
CLECO POWER | Surcharge adjustment, environmental expenses, and timing of collections
Regulatory Assets and Liabilities [Line Items]
Increase (decrease) in deferred fuel costs							22,400,000
CLECO POWER | Mark-to-market value on FTRs
Regulatory Assets and Liabilities [Line Items]
Increase (decrease) in deferred fuel costs							(13,300,000)
CLECO POWER | Fuel surcharges
Regulatory Assets and Liabilities [Line Items]
Increase (decrease) in deferred fuel costs							(4,300,000)
CLECO POWER | Approved removal costs deferral | Tree trimming costs
Regulatory Assets and Liabilities [Line Items]
Maximum amount of costs approved to expend and defer													$ 8,000,000.0
CLECO POWER | TCJA
Regulatory Assets and Liabilities [Line Items]
Amount recovered above the actual PPA capacity costs		$ 374,961,000	$ 348,590,000			$ 374,961,000	$ 374,961,000	$ 348,590,000