ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Other Comprehensive Income (Loss), before Reclassification Adjustments and Tax [Abstract]
Unrealized gain (loss) on investment securities	$ (142,733)	$ (21,920)	$ (454,844)	$ (46,262)
Retirement obligation	0	0	0	0
Total	(142,803)	(21,920)	(454,930)	(46,262)
Other Comprehensive Income (Loss) Reclassifications before Tax [Abstract]
Realized gain (loss) on securities available-for-sale	179	(313)	176	(744)
Retirement obligation	(340)	(567)	(995)	(1,631)
Total	(161)	(880)	(819)	(2,375)
Transactions Pre-tax
Unrealized gain (loss) on investment securities	(142,912)	(21,607)	(455,020)	(45,518)
Unfunded pension obligation	340	567	995	1,631
Total	(142,642)	(21,040)	(454,111)	(43,887)
Transactions Tax-effect
Unrealized gain (loss) on investment securities	31,479	4,664	100,108	9,825
Retirement obligation	(79)	(129)	(134)	(372)
Total	31,400	4,535	99,974	9,453
Transactions Net of tax
Unrealized gain (loss) on investment securities	(111,433)	(16,943)	(354,912)	(35,693)
Retirement obligation	261	438	861	1,259
Total	(111,242)	(16,505)	(354,137)	(34,434)
Balances Net of tax
Unrealized gain (loss) on investment securities	(333,874)	37,883	(333,874)	37,883	$ (222,441)	$ 21,038	$ 54,826	$ 73,576
Retirement obligation	(19,985)	(23,653)	(19,985)	(23,653)	(20,246)	(20,846)	(24,091)	(24,912)
Total	(354,570)	14,230	(354,570)	14,230	(243,328)	(433)	$ 30,735	$ 48,664
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax	(70)		(86)
Other Comprehensive Income (Loss), Reclassification, Foreign Currency Transaction	0		0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(70)		(86)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	0		0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(70)		(86)
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(711)		(711)		$ (641)	$ (625)
Accumulated other comprehensive income (loss)
Transactions Net of tax
Total	$ (111,242)	$ (16,505)	$ (354,137)	$ (34,434)