Pension Plan and Employee Benefits - Amounts Recognized in Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Non-current	$ 283,075	$ 249,264
OTHER BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Current	4,401	4,130
Non-current	48,321	36,325
SERP BENEFITS
Defined Benefit Plan Disclosure [Line Items]
SERP, current	4,599	4,478
SERP, noncurrent	84,529	73,936
CLECO POWER
Defined Benefit Plan Disclosure [Line Items]
Non-current	206,270	182,721
CLECO POWER | OTHER BENEFITS
Defined Benefit Plan Disclosure [Line Items]
Current	3,815	3,584
Non-current	42,080	31,694
CLECO POWER | SERP BENEFITS
Defined Benefit Plan Disclosure [Line Items]
SERP, current	760	930
SERP, noncurrent	$ 13,964	$ 12,025