PARENT COMPANY STATEMENTS - CONDENSED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements, Captions [Line Items]
Other income									$ 2,725	$ 3,564	$ 2,857
Interest expense	$ (3,315)	$ (3,554)	$ (3,964)	$ (4,298)	$ (5,141)	$ (6,066)	$ (7,303)	$ (11,585)	(15,131)	(30,095)	(60,163)
Income tax benefit	(5,507)	(5,469)	(5,705)	(5,030)	(6,071)	(5,377)	(4,448)	(3,643)	(21,711)	(19,539)	(20,338)
NET INCOME	$ 24,283	$ 24,119	$ 24,348	$ 22,983	$ 24,592	$ 22,776	$ 19,670	$ 17,299	95,733	84,337	87,047
COMPREHENSIVE INCOME									84,082	100,022	105,297
Reportable Legal Entities | Parent Company
Condensed Financial Statements, Captions [Line Items]
Other income									3	0	155
Interest expense									(7)	0	(1,720)
Miscellaneous expense									(8,133)	(3,935)	(5,321)
INCOME BEFORE INCOME TAXES AND EQUITY IN UNDISTRIBUTED INCOME OF SUBSIDIARIES									40,253	29,444	52,258
Income tax benefit									2,360	1,065	2,256
INCOME BEFORE EQUITY IN UNDISTRIBUTED INCOME OF SUBSIDIARIES									42,613	30,509	54,514
Equity in undistributed income of subsidiaries									53,120	53,828	32,533
NET INCOME									95,733	84,337	87,047
COMPREHENSIVE INCOME									84,082	100,022	105,297
Reportable Legal Entities | Parent Company | Lake City Bank
Condensed Financial Statements, Captions [Line Items]
Dividends from Lake City Bank, Lakeland Statutory Trust II									47,355	32,079	57,842
Reportable Legal Entities | Parent Company | Non-bank Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Dividends from Lake City Bank, Lakeland Statutory Trust II									$ 1,035	$ 1,300	$ 1,302