Seacoast Banking Corporation of Florida (Parent Company Only) Financial Information - Summary of Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Other assets	$ 128,117	$ 116,590
Total Assets	6,747,659	5,810,129
Liabilities and Shareholders' Equity
Subordinated debt	70,804	70,521
Other liabilities	41,025	30,130
Shareholders' equity	864,267	689,664	$ 435,397	$ 353,453
Total Liabilities & Shareholders' Equity	6,747,659	5,810,129
Parent Company
Assets
Cash	197	1,154
Securities purchased under agreement to resell with subsidiary bank, maturing within 30 days	40,130	33,151
Investment in subsidiaries	897,683	711,973
Other assets	777	21,337
Total Assets	938,787	767,615
Liabilities and Shareholders' Equity
Subordinated debt	70,804	70,521
Other liabilities	3,716	7,430
Shareholders' equity	864,267	689,664
Total Liabilities & Shareholders' Equity	$ 938,787	$ 767,615