ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Summary of the Accumulated Other Comprehensive Loss Balances, Net of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrealized losses on available for sale securities
Balance at the beginning of the period	$ (11,337)
Current Period Change	(348)	$ (505)	$ (4,082)
Balance at the end of the period	11,685	(11,337)
Unrealized losses on pension benefits
Balance at the beginning of the period	(5,533)
Current Period Change	(832)	193	(630)
Balance at the end of the period	(6,365)	(5,533)
Unrealized gains on cash flow hedges
Balance at the beginning of the period	1,931
Current Period Change	1,007	1,089	1,270
Balance at the end of the period	2,938	1,931
Accumulated other comprehensive loss, net of income taxes
Balance at the beginning of the period	(14,939)
Current Period Change	(173)	777	$ (3,442)
Balance at the end of the period	$ (15,112)	$ (14,939)