Business Combinations - Additional Information (Details)					12 Months Ended
	Jan. 31, 2023 branch	Oct. 07, 2022 USD ($) branch	Jan. 03, 2022 USD ($) branch	Aug. 06, 2021 USD ($) branch	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Specific reserve					$ 113,895,000	$ 83,315,000	$ 92,733,000	$ 35,154,000
Goodwill					480,319,000	252,154,000	221,176,000	$ 205,286,000
Share-based compensation expense					11,155,000	8,685,000	7,304,000
Acquisition costs					27,900,000	7,900,000	$ 9,100,000
Stock options
Business Acquisition [Line Items]
Fair value of options and warrants converted					10,400,000	4,700,000
Apollo Bancshares, Inc.
Business Acquisition [Line Items]
Number of branches acquired | branch		5
Exchange ratio (in shares)		1.006529
Minority interest portion, number of Seacoast stock for each share of stock converted (in shares)		1.195651
Goodwill, nondeductible for tax purposes		$ 90,200,000
Fair value of options and warrants converted		6,530,000
Specific reserve		7,800,000
Goodwill		90,237,000
Deposits		854,774,000
Apollo Bancshares, Inc. | PCD Loans
Business Acquisition [Line Items]
Allowance for credit losses at acquisition		(2,658,000)
Total purchased credit-impaired loan acquired		90,895,000
Apollo Bancshares, Inc. | Acquired Non-PCD Loans
Business Acquisition [Line Items]
Specific reserve		$ 5,100,000
Drummond Banking Company
Business Acquisition [Line Items]
Number of branches acquired | branch		18
Exchange ratio (in shares)		51.9561
Specific reserve		$ 12,500,000
Percentage of common stock acquired		100.00%
Goodwill		$ 103,476,000
Deposits		881,281,000
Drummond Banking Company | PCD Loans
Business Acquisition [Line Items]
Allowance for credit losses at acquisition		(2,566,000)
Total purchased credit-impaired loan acquired		51,705,000
Drummond Banking Company | Acquired Non-PCD Loans
Business Acquisition [Line Items]
Specific reserve		$ 9,900,000
Business Bank of Florida
Business Acquisition [Line Items]
Number of branches acquired | branch			1
Exchange ratio (in shares)			0.7997
Goodwill, nondeductible for tax purposes			$ 8,000,000
Fair value of options and warrants converted			497,000
Specific reserve			$ 1,800,000
Percentage of common stock acquired			100.00%
Goodwill			$ 7,962,000
Deposits			166,326,000
Business Bank of Florida | Stock options | Seacoast 2021 Incentive Plan
Business Acquisition [Line Items]
Fair value of options and warrants converted			500,000
Business Bank of Florida | PCD Loans
Business Acquisition [Line Items]
Specific reserve			15,000
Allowance for credit losses at acquisition			(15,000)
Total purchased credit-impaired loan acquired			651,000
Business Bank of Florida | Acquired Non-PCD Loans
Business Acquisition [Line Items]
Specific reserve			$ 1,800,000
Sabal Palm Bancorp, Inc.
Business Acquisition [Line Items]
Number of branches acquired | branch			3
Exchange ratio (in shares)			0.2203
Goodwill, nondeductible for tax purposes			$ 26,500,000
Fair value of options and warrants converted			3,336,000
Specific reserve			$ 3,400,000
Percentage of common stock acquired			100.00%
Goodwill			$ 26,489,000
Deposits			395,952,000
Sabal Palm Bancorp, Inc. | Stock options | Seacoast 2021 Incentive Plan
Business Acquisition [Line Items]
Fair value of options and warrants converted			3,300,000
Sabal Palm Bancorp, Inc. | PCD Loans
Business Acquisition [Line Items]
Specific reserve			37,000
Allowance for credit losses at acquisition			(37,000)
Total purchased credit-impaired loan acquired			3,003,000
Sabal Palm Bancorp, Inc. | Acquired Non-PCD Loans
Business Acquisition [Line Items]
Specific reserve			$ 3,400,000
Legacy Bank of Florida
Business Acquisition [Line Items]
Number of branches acquired | branch				5
Exchange ratio (in shares)				0.1703
Goodwill, nondeductible for tax purposes				$ 31,000,000
Fair value of options and warrants converted				4,736,000
Specific reserve				$ 11,200,000
Percentage of common stock acquired				100.00%
Goodwill				$ 30,978,000
Deposits				494,921,000
Legacy Bank of Florida | Stock options | Seacoast 2021 Incentive Plan
Business Acquisition [Line Items]
Fair value of options and warrants converted						4,700,000
Share-based compensation expense						$ 900,000
Legacy Bank of Florida | PCD Loans
Business Acquisition [Line Items]
Specific reserve				3,000,000
Allowance for credit losses at acquisition				(3,046,000)
Total purchased credit-impaired loan acquired				62,589,000
Legacy Bank of Florida | Acquired Non-PCD Loans
Business Acquisition [Line Items]
Specific reserve				$ 8,200,000
Professional Holding Corp.
Business Acquisition [Line Items]
Deposits					2,200,000,000
Total purchased credit-impaired loan acquired					$ 2,100,000,000
Professional Holding Corp. | Subsequent Event
Business Acquisition [Line Items]
Exchange ratio (in shares)	0.8909
Percentage of common stock acquired	100.00%
Number of branches operated | branch	9