ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Components and Related Income Tax Effects (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)
Unrealized holding losses on available for sale securities	$ (8,429)	$ (1,107)	$ (6,428)
Reclassification adjustment for losses (gains) realized in income	7,921	(38)	(449)
Income tax effect	160	640	2,795
Net change in unrealized losses on available for sale securities	(348)	(505)	(4,082)
Unrealized net loss arising during the period	1,567	302	1,452
Reclassification adjustment for amortization realized in income	384	480	384
Income tax effect	351	15	438
Net change in post-retirement obligation	(832)	193	(630)
Change in fair value of derivatives used for cash flow hedges	2,493	463	1,191
Reclassification adjustment for (gains) losses realized in income	(1,068)	1,419	944
Income tax effect	(418)	(793)	(865)
Net change in unrealized gain on cash flow hedges	1,007	1,089	1,270
Other comprehensive (loss) income	$ (173)	$ 777	$ (3,442)

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