BUSINESS COMBINATIONS - Summary of Acquired Identifiable Assets and Liabilities (Details) - USD ($) $ in Thousands			9 Months Ended
	Apr. 03, 2020	Nov. 01, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Liabilities and equity:
Bargain purchase gain			$ (7,023)	$ 0
Goodwill resulting from acquisition			$ 158,572		$ 158,572
SWG
Purchase price:
Cash and stock	$ 47,858
Total purchase price	47,858
Identifiable assets:
Cash and due from banks	29,247
Investments	89,737
Loans	392,292
Core deposit intangible	4,556
Personal and real property	18,558
Bank owned life insurance	6,963
Other assets	2,588
Total assets	543,941
Liabilities and equity:
Deposits	476,099
Borrowed funds	9,500
Other liabilities	3,461
Total liabilities	489,060
Net assets acquired	54,881
Bargain purchase gain	$ (7,023)
First Florida Bancorp, Inc
Purchase price:
Cash and stock		$ 89,520
Total purchase price		89,520
Identifiable assets:
Cash and due from banks		50,169
Investments		122,084
Loans		247,263
Core deposit intangible		3,745
Personal and real property		4,991
Other assets		2,283
Total assets		430,535
Liabilities and equity:
Deposits		373,908
Borrowed funds		5,527
Other liabilities		1,619
Total liabilities		381,054
Net assets acquired		49,481
Goodwill resulting from acquisition		$ 40,039