Seacoast Banking Corporation of Florida (Parent Company Only) Financial Information - Summary of Statement of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Adjustments to reconcile net income to net cash provided by operating activities:
Net Income	$ 124,403	$ 77,764	$ 98,739
Net (increase) decrease in other assets	(42,437)	(35,555)	(5,614)
Net increase (decrease) in other liabilities	28,883	18,776	(4,206)
Net Cash Provided by Operating Activities	154,572	60,652	117,745
Cash Flows From Investing Activities
Net Cash Used in Investing Activities	(412,511)	(342,502)	(321,341)
Cash Flows From Financing Activities
Dividends paid	(22,506)	0	0
Stock based employee benefit plans	5,022
Stock based employee benefit plans		(1,486)	(2,135)
Net Cash Provided by Financing Activities	591,580	561,407	212,176
Net increase in cash and cash equivalents	333,641	279,557	8,580
Cash and Cash Equivalents at Beginning of Year	404,088	124,531	115,951
Cash and Cash Equivalents at End of Year	737,729	404,088	124,531
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	9,977	23,548	46,130
Parent Company
Adjustments to reconcile net income to net cash provided by operating activities:
Net Income	124,403	77,764	98,739
Equity in undistributed income of subsidiaries	(78,519)	(59,749)	(83,293)
Net (increase) decrease in other assets	(489)	1,772	(738)
Net increase (decrease) in other liabilities	400	256	265
Net Cash Provided by Operating Activities	45,795	20,043	14,973
Cash Flows From Investing Activities
Net cash paid for bank acquisition	0	(1,462)	0
Net (advances)/repayments with subsidiary	(28,324)	(17,095)	(12,861)
Net Cash Used in Investing Activities	(28,324)	(18,557)	(12,861)
Cash Flows From Financing Activities
Dividends paid	(22,506)	0	0
Stock based employee benefit plans	5,022
Stock based employee benefit plans		(1,486)	(2,239)
Net Cash Provided by Financing Activities	(17,484)	(1,486)	(2,239)
Net increase in cash and cash equivalents	(13)	0	(127)
Cash and Cash Equivalents at Beginning of Year	70	70	197
Cash and Cash Equivalents at End of Year	57	70	70
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	$ 1,441	$ 1,992	$ 3,186