INVESTMENT SECURITIES - Amortized Cost and Estimated Fair Value of Investment Securities Available for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,068,350		$ 572,887
Allowance for Credit Losses	(88)	$ 0	0	$ (81)	$ (101)	$ (112)
Gross Unrealized Gains	689		19,929
Gross Unrealized Losses	(16,683)		(195)
Estimated Fair Value	1,052,268		592,621
U.S. Treasuries
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	314,613
Allowance for Credit Losses	0
Gross Unrealized Gains	0
Gross Unrealized Losses	(1,724)
Estimated Fair Value	312,889
U.S. government-sponsored agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,050		7,084
Allowance for Credit Losses	0		0
Gross Unrealized Gains	0		88
Gross Unrealized Losses	(29)		0
Estimated Fair Value	2,021		7,172
State, county and municipal securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	41,428		45,470
Allowance for Credit Losses	0		0
Gross Unrealized Gains	261		2,342
Gross Unrealized Losses	(726)		0
Estimated Fair Value	40,963		47,812
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	15,897		27,897
Allowance for Credit Losses	(88)		0
Gross Unrealized Gains	2		719
Gross Unrealized Losses	(348)		(120)
Estimated Fair Value	15,463		28,496
SBA pool securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	35,854		44,312
Allowance for Credit Losses	0		0
Gross Unrealized Gains	6		958
Gross Unrealized Losses	(1,429)		(69)
Estimated Fair Value	34,431		45,201
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	658,508		448,124
Allowance for Credit Losses	0		0
Gross Unrealized Gains	420		15,822
Gross Unrealized Losses	(12,427)		(6)
Estimated Fair Value	$ 646,501		$ 463,940