Seacoast Banking Corporation of Florida (Parent Company Only) Financial Information - Summary of Statements of Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income
Gain on sale of Visa stock	$ 0	$ 0	$ 15,153
Total Interest Income	289,823	241,398	191,596
Interest expense	46,205	29,883	15,300
Other expenses	15,177	17,222	15,535
Income tax (benefit) provision	29,873	20,259	36,336
Net Income	98,739	67,275	42,865
Parent Company
Income
Interest/other	679	484	2,104
Dividends from subsidiary Bank	0	0	0
Gain on sale of Visa stock	0	0	15,153
Total Interest Income	679	484	17,257
Interest expense	3,368	3,165	2,499
Other expenses	651	879	649
(Loss) income before income taxes and equity in undistributed income of subsidiaries	(3,340)	(3,560)	14,109
Income tax (benefit) provision	(702)	(747)	4,938
(Loss) Income before equity in undistributed income of subsidiaries	(2,638)	(2,813)	9,171
Equity in undistributed income of subsidiaries	101,377	70,088	33,694
Net Income	$ 98,739	$ 67,275	$ 42,865