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, 2019	Dec. 31, 2018	Dec. 31, 2017
Adjustments to reconcile net income to net cash provided by operating activities:
Net Income	$ 98,739	$ 67,275	$ 42,865
Gain on sale of Visa Class B stock	0	0	(15,153)
Net (increase) decrease in other assets	(5,614)	10,331	(5,506)
Net increase (decrease) in other liabilities	(4,206)	8,827	(21,432)
Net Cash Provided by Operating Activities	117,745	129,608	48,909
Cash Flows From Investing Activities
Purchase of Visa Class B stock	0	0	(6,180)
Net Cash Used in Investing Activities	(321,341)	(174,600)	(245,576)
Cash Flows From Financing Activities
Issuance of common stock, net of related expense	0	0	55,641
Net Cash Provided by Financing Activities	212,176	51,439	196,527
Net increase (decrease) in cash and cash equivalents	8,580	6,447	(140)
Cash and cash equivalents at beginning of year	115,951	109,504	109,644
Cash and Cash Equivalents at End of Year	124,531	115,951	109,504
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	46,130	28,301	15,125
Parent Company
Adjustments to reconcile net income to net cash provided by operating activities:
Net Income	98,739	67,275	42,865
Equity in undistributed income of subsidiaries	(101,377)	(70,088)	(33,694)
Gain on sale of Visa Class B stock	0	0	(15,153)
Net (increase) decrease in other assets	(738)	(10,045)	1,415
Net increase (decrease) in other liabilities	265	(3,431)	4,005
Net Cash Provided by Operating Activities	(3,111)	(16,289)	(562)
Cash Flows From Investing Activities
Net cash paid for bank acquisition	0	(6,558)	(27,862)
Investment in unconsolidated subsidiary	(10)	0	0
Purchase of Visa Class B stock	0	0	(6,180)
Proceeds from sale of Visa Class B stock	0	21,333	0
Dividends from bank subsidiary	18,082	0	0
(Increase) decrease in securities purchased under agreement to resell, maturing within 30 days, net	(12,849)	(421)	(20,475)
Net Cash Used in Investing Activities	5,223	14,354	(54,517)
Cash Flows From Financing Activities
Issuance of common stock, net of related expense	0	0	55,641
Stock based employment benefit plans	(2,239)	978	(56)
Net Cash Provided by Financing Activities	(2,239)	978	55,585
Net increase (decrease) in cash and cash equivalents	(127)	(957)	506
Cash and cash equivalents at beginning of year	197	1,154	648
Cash and Cash Equivalents at End of Year	70	197	1,154
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	$ 3,186	$ 2,936	$ 2,205