Recent Authoritative Guidance - ASU 2016-18 (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018		Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used in investing activities	$ (142,245)		$ (125,069)
Net decrease in cash, cash equivalents, restricted cash, and restricted cash equivalents	(6,865)		(18,568)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period	152,202	[1]	69,571
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	145,337	[2]	51,003
Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Transfer of cash from restricted accounts, net			0
Net cash used in investing activities			(125,069)
Net decrease in cash, cash equivalents, restricted cash, and restricted cash equivalents			(18,568)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period			69,571
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period			51,003
AS REPORTED | Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Transfer of cash from restricted accounts, net			6,003
Net cash used in investing activities			(119,066)
Net decrease in cash, cash equivalents, restricted cash, and restricted cash equivalents			(12,565)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period			23,077
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period			10,512
CLECO POWER
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used in investing activities	(144,652)		(123,884)
Net decrease in cash, cash equivalents, restricted cash, and restricted cash equivalents	(2,374)		(24,016)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period	102,957	[3]	67,955
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period	$ 100,583	[4]	43,939
CLECO POWER | Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Transfer of cash from restricted accounts, net			0
Net cash used in investing activities			(123,884)
Net decrease in cash, cash equivalents, restricted cash, and restricted cash equivalents			(24,016)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period			67,955
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period			43,939
CLECO POWER | AS REPORTED | Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Transfer of cash from restricted accounts, net			6,003
Net cash used in investing activities			(117,881)
Net decrease in cash, cash equivalents, restricted cash, and restricted cash equivalents			(18,013)
Cash, cash equivalents, restricted cash, and restricted cash equivalents at beginning of period			21,482
Cash, cash equivalents, restricted cash, and restricted cash equivalents at end of period			$ 3,469

[1] Includes cash and cash equivalents are $119,040, current restricted cash and cash equivalents are $13,081, non-current restricted cash and cash equivalents are $20,081.

[2] Includes cash and cash equivalents are $116,312, current restricted cash and cash equivalents are $9,945, non-current restricted cash and cash equivalents are $19,080.

[3] Includes cash and cash equivalents are $69,816, current restricted cash and cash equivalents are $13,081, non-current restricted cash and cash equivalents are $20,060.

[4] Includes cash and cash equivalents are $71,579, current restricted cash and cash equivalents are $9,945, non-current restricted cash and cash equivalents are $19,059.