OPERATING SEGMENTS AND RELATED INFORMATION - Schedule of Financial Results by Operating Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Interest income	$ 523,681	$ 480,543	$ 360,176
Intersegment interest income	0	0	0
Interest expense	201,070	159,922	36,548
Intersegment interest expense	0	0	0
Net interest income	322,611	320,621	323,628
Provision for credit losses	8,590	2,399	4,623
Net interest income after provision for credit losses	314,021	318,222	319,005
Noninterest income
All other noninterest income	23,136	13,669	18,057
Intersegment noninterest income	0	0	0
Total noninterest income	139,682	121,214	126,613
Revenue	462,293	441,835	450,241
Noninterest expense
Salaries, wages, and employee benefits	175,619	162,597	159,016
Data processing	27,124	23,708	21,648
Amortization of intangible assets	10,057	10,432	11,628
Interchange expense	6,001	6,864	6,298
Other noninterest expense	81,598	81,931	85,291
Intersegment noninterest expense	0	0	0
Total noninterest expense	300,399	285,532	283,881
Income (loss) before income taxes	153,304	153,904	161,737
Income taxes	39,613	31,339	33,426
Net income	113,691	122,565	128,311
Wealth management fees
Noninterest income
Noninterest income	63,630	57,309	55,378
Fees for customer services
Noninterest income
Noninterest income	30,933	29,044	33,111
Payment technology solutions
Noninterest income
Noninterest income	21,983	21,192	20,067
Other
Segment Reporting Information [Line Items]
Interest income	33	105	50
Intersegment interest income	(372)	(54)	(65)
Interest expense	17,944	19,005	17,854
Intersegment interest expense	(2,664)	(3,006)	(1,159)
Net interest income	(15,619)	(15,948)	(16,710)
Provision for credit losses	0	0	0
Net interest income after provision for credit losses	(15,619)	(15,948)	(16,710)
Noninterest income
All other noninterest income	942	(2,182)	(1,846)
Intersegment noninterest income	(2,473)	(2,703)	(2,618)
Total noninterest income	(1,531)	(4,885)	(4,464)
Revenue	(17,150)	(20,833)	(21,174)
Noninterest expense
Salaries, wages, and employee benefits	21,128	17,767	20,965
Data processing	538	541	545
Amortization of intangible assets	0	0	0
Interchange expense	0	0	0
Other noninterest expense	9,593	6,015	6,739
Intersegment noninterest expense	(15,996)	(16,976)	(18,528)
Total noninterest expense	15,263	7,347	9,721
Income (loss) before income taxes	(32,413)	(28,180)	(30,895)
Income taxes	(7,478)	(7,258)	(8,220)
Net income	(24,935)	(20,922)	(22,675)
Other | Wealth management fees
Noninterest income
Noninterest income	0	0	0
Other | Fees for customer services
Noninterest income
Noninterest income	0	0	0
Other | Payment technology solutions
Noninterest income
Noninterest income	0	0	0
Banking | Operating Segments
Segment Reporting Information [Line Items]
Interest income	523,648	480,438	360,126
Intersegment interest income	324	0	0
Interest expense	183,126	140,917	18,694
Intersegment interest expense	2,664	3,006	1,159
Net interest income	338,182	336,515	340,273
Provision for credit losses	8,590	2,399	4,623
Net interest income after provision for credit losses	329,592	334,116	335,650
Noninterest income
All other noninterest income	20,871	15,337	19,890
Intersegment noninterest income	1,402	1,149	962
Total noninterest income	53,206	45,530	53,963
Revenue	391,388	382,045	394,236
Noninterest expense
Salaries, wages, and employee benefits	117,730	111,834	107,159
Data processing	20,631	18,217	16,420
Amortization of intangible assets	8,916	8,963	9,831
Interchange expense	0	0	0
Other noninterest expense	66,433	71,259	73,544
Intersegment noninterest expense	11,457	13,178	15,042
Total noninterest expense	225,167	223,451	221,996
Income (loss) before income taxes	157,631	156,195	167,617
Income taxes	40,365	32,342	36,021
Net income	117,266	123,853	131,596
Banking | Operating Segments | Wealth management fees
Noninterest income
Noninterest income	0	0	0
Banking | Operating Segments | Fees for customer services
Noninterest income
Noninterest income	30,933	29,044	33,111
Banking | Operating Segments | Payment technology solutions
Noninterest income
Noninterest income	0	0	0
Wealth Management | Operating Segments
Segment Reporting Information [Line Items]
Interest income	0	0	0
Intersegment interest income	0	0	0
Interest expense	0	0
Intersegment interest expense	0	0	0
Net interest income	0	0	0
Provision for credit losses	0	0	0
Net interest income after provision for credit losses	0	0	0
Noninterest income
All other noninterest income	1,323	514	16
Intersegment noninterest income	0	0	0
Total noninterest income	64,953	57,823	55,394
Revenue	64,953	57,823	55,394
Noninterest expense
Salaries, wages, and employee benefits	26,631	24,474	22,993
Data processing	2,263	1,937	1,962
Amortization of intangible assets	1,141	1,469	1,797
Interchange expense	0	0	0
Other noninterest expense	2,836	2,503	2,593
Intersegment noninterest expense	3,096	2,698	2,200
Total noninterest expense	35,967	33,081	31,545
Income (loss) before income taxes	28,986	24,742	23,849
Income taxes	6,956	5,938	5,306
Net income	22,030	18,804	18,543
Wealth Management | Operating Segments | Wealth management fees
Noninterest income
Noninterest income	63,630	57,309	55,378
Wealth Management | Operating Segments | Fees for customer services
Noninterest income
Noninterest income	0	0	0
Wealth Management | Operating Segments | Payment technology solutions
Noninterest income
Noninterest income	0	0	0
FirsTech | Operating Segments
Segment Reporting Information [Line Items]
Interest income	0	0	0
Intersegment interest income	48	54	65
Interest expense	0	0	0
Intersegment interest expense	0	0	0
Net interest income	48	54	65
Provision for credit losses	0	0	0
Net interest income after provision for credit losses	48	54	65
Noninterest income
All other noninterest income	0	0	(3)
Intersegment noninterest income	1,071	1,554	1,656
Total noninterest income	23,054	22,746	21,720
Revenue	23,102	22,800	21,785
Noninterest expense
Salaries, wages, and employee benefits	10,130	8,522	7,899
Data processing	3,692	3,013	2,721
Amortization of intangible assets	0	0	0
Interchange expense	6,001	6,864	6,298
Other noninterest expense	2,736	2,154	2,415
Intersegment noninterest expense	1,443	1,100	1,286
Total noninterest expense	24,002	21,653	20,619
Income (loss) before income taxes	(900)	1,147	1,166
Income taxes	(230)	317	319
Net income	(670)	830	847
FirsTech | Operating Segments | Wealth management fees
Noninterest income
Noninterest income	0	0	0
FirsTech | Operating Segments | Fees for customer services
Noninterest income
Noninterest income	0	0	0
FirsTech | Operating Segments | Payment technology solutions
Noninterest income
Noninterest income	$ 21,983	$ 21,192	$ 20,067