ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Changes in AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	$ 546,685
Total other comprehensive (loss) income, net of tax	(28,088)	$ 11,719	$ 27,602
Balance at the end of the period	558,219	546,685
Investment Securities
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	26,651	14,825	(9,643)
Other comprehensive income (loss) before reclassifications	(30,207)	11,679	27,594
Amounts reclassified from AOCI	(110)	147	(26)
Total other comprehensive (loss) income, net of tax	(30,317)	11,826	27,568
Balance at the end of the period	(3,666)	26,651	14,825
Investment Securities \| Impact of adoption of new accounting standards
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			(3,100)
Investment Securities \| Adjusted balance at beginning of period
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			(12,743)
Defined Benefit Plans
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	(6,523)	(6,416)	(6,450)
Other comprehensive income (loss) before reclassifications	1,470	(980)	(810)
Amounts reclassified from AOCI	759	873	844
Total other comprehensive (loss) income, net of tax	2,229	(107)	34
Balance at the end of the period	(4,294)	(6,523)	(6,416)
Defined Benefit Plans \| Impact of adoption of new accounting standards
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			0
Defined Benefit Plans \| Adjusted balance at beginning of period
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			(6,450)
AOCI
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period	20,128	8,409	(16,093)
Other comprehensive income (loss) before reclassifications	(28,737)	10,699	26,784
Amounts reclassified from AOCI	649	1,020	818
Total other comprehensive (loss) income, net of tax	(28,088)	11,719	27,602
Balance at the end of the period	$ (7,960)	$ 20,128	8,409
AOCI \| Impact of adoption of new accounting standards
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			(3,100)
AOCI \| Adjusted balance at beginning of period
Changes in each component of accumulated other comprehensive income (loss), net of tax
Balance at the beginning of the period			$ (19,193)