EMPLOYEE BENEFITS - Amounts Recognized as a Component of Other Comprehensive Income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net (loss) gain occurring during the year	$ 1,994	$ 5,218	$ 3,132
Net prior service (cost) credit occurring during the year	0	0	121
Defined Benefit Pension Plan
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Recognition of net loss	1,512	1,312	1,642
Recognition of prior service (credit) cost	(14)	(14)	(14)
Recognition of loss (gain) due to settlements	0	0	0
Net (loss) gain occurring during the year	(1,581)	(3,317)	(2,541)
Net prior service (cost) credit occurring during the year	0	0	(121)
Total adjustment during the year	(83)	(2,019)	(1,034)
Deferred tax benefit (expense)	17	241	362
Other comprehensive (loss) income, net of tax	(66)	(1,778)	(672)
Defined Benefit Pension Plan Acquired
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Recognition of net loss	0	0	0
Recognition of prior service (credit) cost	0	0	0
Recognition of loss (gain) due to settlements	0	8	(8)
Net (loss) gain occurring during the year	(69)	(150)	(354)
Net prior service (cost) credit occurring during the year	0	0	0
Total adjustment during the year	(69)	(142)	(362)
Deferred tax benefit (expense)	14	30	127
Other comprehensive (loss) income, net of tax	(55)	(112)	(235)
Restoration Plan
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Recognition of net loss	677	301	186
Recognition of prior service (credit) cost	7	6	6
Recognition of loss (gain) due to settlements	0	0	0
Net (loss) gain occurring during the year	(344)	(1,751)	(237)
Net prior service (cost) credit occurring during the year	0	0	0
Total adjustment during the year	340	(1,444)	(45)
Deferred tax benefit (expense)	(71)	259	16
Other comprehensive (loss) income, net of tax	$ 269	$ (1,185)	$ (29)