SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Reclassification out of Accumulated Other Comprehensive Income (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
Other comprehensive income/(loss):
Other comprehensive income/(loss) before tax	$ 8,338			$ (1,883)			$ 47,583	$ 18,993
Provision (Benefit)
Other comprehensive income/(loss), provision (benefit)	1,751			(395)			9,992	3,989
After Tax
Unrealized (losses) / gain, after tax	11,157			2,620			51,797	27,484
Less reclassification adjustments, provision (benefit)	(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
Accumulated Other Comprehensive Income (Loss)
Other comprehensive income/(loss):
Other comprehensive income/(loss) before tax	8,338			(1,883)			47,583	18,993
Provision (Benefit)
Other comprehensive income/(loss), provision (benefit)	1,751			(395)			9,992	3,989
After Tax
Other comprehensive income/(loss) net of tax	6,587	$ (5,023)	$ 36,027	(1,488)	$ 25,511	$ (9,019)	37,591	15,004
Securities | Available-for-Sale Securities
Other comprehensive income/(loss):
Unrealized (losses) / gain, before tax	26,354			22,081			62,079	46,084
Other comprehensive income/(loss) before tax	26,350			22,076			61,015	46,068
Provision (Benefit)
Unrealized (losses) / gain, provision (benefit)	5,534			4,638			13,037	9,678
Other comprehensive income/(loss), provision (benefit)	5,533			4,637			12,813	9,675
After Tax
Unrealized (losses) / gain, after tax	20,820			17,443			49,042	36,406
Other comprehensive income/(loss) net of tax	20,817			17,439			48,202	36,393
Securities | Held-to-Maturity Securities
Other comprehensive income/(loss):
Unrealized (losses) / gain, before tax	0			(31,898)			0	(31,898)
Less reclassification adjustments, before tax	(443)			373			(757)	(730)
Other comprehensive income/(loss) before tax	(443)			(31,525)			(757)	(32,628)
Provision (Benefit)
Unrealized (losses) / gain, provision (benefit)	0			(6,699)			0	(6,699)
Less reclassification adjustments, provision (benefit)	(93)			79			(159)	(153)
Other comprehensive income/(loss), provision (benefit)	(93)			(6,620)			(159)	(6,852)
After Tax
Unrealized (losses) / gain, after tax	0			(25,199)			0	(25,199)
Less reclassification adjustments, provision (benefit)	(350)			294			(598)	(577)
Other comprehensive income/(loss) net of tax	(350)			(24,905)			(598)	(25,776)
Securities | Gain on sale of available-for sale investment securities | Available-for-Sale Securities
Other comprehensive income/(loss):
Less reclassification adjustments, before tax	0			0			(1,052)	0
Provision (Benefit)
Less reclassification adjustments, provision (benefit)	0			0			(221)	0
After Tax
Less reclassification adjustments, provision (benefit)	0			0			(831)	0
Securities | Other income | Available-for-Sale Securities
Other comprehensive income/(loss):
Less reclassification adjustments, before tax	(4)			(5)			(12)	(16)
Provision (Benefit)
Less reclassification adjustments, provision (benefit)	(1)			(1)			(3)	(3)
After Tax
Less reclassification adjustments, provision (benefit)	(3)			(4)			(9)	(13)
Cash Flow Hedges
Other comprehensive income/(loss):
Unrealized (losses) / gain, before tax	(12,232)			13,135			3,488	20,604
Less reclassification adjustments, before tax	(5,337)			(5,569)			(16,163)	(15,051)
Other comprehensive income/(loss) before tax	(17,569)			7,566			(12,675)	5,553
Provision (Benefit)
Unrealized (losses) / gain, provision (benefit)	(2,569)			2,759			733	4,327
Less reclassification adjustments, provision (benefit)	(1,120)			(1,171)			(3,395)	(3,161)
Other comprehensive income/(loss), provision (benefit)	(3,689)			1,588			(2,662)	1,166
After Tax
Unrealized (losses) / gain, after tax	(9,663)			10,376			2,755	16,277
Less reclassification adjustments, provision (benefit)	(4,217)			(4,398)			(12,768)	(11,890)
Other comprehensive income/(loss) net of tax	$ (13,880)			$ 5,978			$ (10,013)	$ 4,387