SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Accumulated Other Comprehensive Income, Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,500,979	$ 1,480,343	$ 1,411,863	$ 1,346,555	$ 1,292,385	$ 1,271,958	$ 1,411,863	$ 1,271,958
Other comprehensive income/(loss) before reclassifications	11,157			2,620			51,797	27,484
Amounts reclassified from AOCI	(4,570)			(4,108)			(14,206)	(12,480)
Other comprehensive income/(loss) net of tax	6,587	(5,023)	36,027	(1,488)	25,511	(9,019)	37,591	15,004
Ending balance	1,462,344	1,500,979	1,480,343	1,385,267	1,346,555	1,292,385	1,462,344	1,385,267
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(9,141)	(4,118)	(40,145)	(34,351)	(59,862)	(50,843)	(40,145)	(50,843)
Other comprehensive income/(loss) net of tax	6,587	(5,023)	36,027	(1,488)	25,511	(9,019)	37,591	15,004
Ending balance	(2,554)	(9,141)	(4,118)	(35,839)	(34,351)	(59,862)	(2,554)	(35,839)
AOCI, Securities | Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(41,062)		(68,447)	(96,607)		(115,561)	(68,447)	(115,561)
Other comprehensive income/(loss) before reclassifications	20,820			17,443			49,042	36,406
Amounts reclassified from AOCI	(3)			(4)			(840)	(13)
Other comprehensive income/(loss) net of tax	20,817			17,439			48,202	36,393
Ending balance	(20,245)	(41,062)		(79,168)	(96,607)		(20,245)	(79,168)
AOCI, Securities | Held-to-Maturity Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(8,972)		(8,724)	15,486		16,357	(8,724)	16,357
Other comprehensive income/(loss) before reclassifications	0			(25,199)			0	(25,199)
Amounts reclassified from AOCI	(350)			294			(598)	(577)
Other comprehensive income/(loss) net of tax	(350)			(24,905)			(598)	(25,776)
Ending balance	(9,322)	(8,972)		(9,419)	15,486		(9,322)	(9,419)
AOCI, Cash Flow Hedge
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	40,893		$ 37,026	46,770		$ 48,361	37,026	48,361
Other comprehensive income/(loss) before reclassifications	(9,663)			10,376			2,755	16,277
Amounts reclassified from AOCI	(4,217)			(4,398)			(12,768)	(11,890)
Other comprehensive income/(loss) net of tax	(13,880)			5,978			(10,013)	4,387
Ending balance	$ 27,013	$ 40,893		$ 52,748	$ 46,770		$ 27,013	$ 52,748