Seacoast Banking Corporation of Florida (Parent Company Only) Financial Information - Summary of Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Other assets	$ 201,857	$ 162,214
Total Assets	9,681,433	8,342,392
Liabilities and Shareholders' Equity
Subordinated debt	71,646	71,365
Other liabilities	109,897	88,455
Shareholders' equity	1,310,736	1,130,402	$ 985,639	$ 864,267
Total Liabilities & Shareholders' Equity	9,681,433	8,342,392
Parent Company
Assets
Cash	57	70
Securities purchased under agreement to resell with subsidiary bank, maturing within 30 days	98,398	70,074
Investment in subsidiaries	1,286,478	1,134,536
Other assets	1,140	659
Total Assets	1,386,073	1,205,339
Liabilities and Shareholders' Equity
Subordinated debt	71,646	71,365
Other liabilities	3,795	3,676
Shareholders' equity	1,310,632	1,130,298
Total Liabilities & Shareholders' Equity	$ 1,386,073	$ 1,205,339