PENSION AND OTHER POST-EMPLOYMENT BENEFITS - Schedule of Other Changes to Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss (gain)	$ 2,390	$ 12,794
Prior service (credit)	0	0
Amortization of:
Prior service credit	0	0
Actuarial (loss) gain	(988)	(704)
Loss recognized related to settlement	(5,735)	(2,162)
Total recognized in OCI	(4,333)	9,928
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial loss (gain)	(43)	(227)
Prior service (credit)	0	(1,400)
Amortization of:
Prior service credit	730	1,485
Actuarial (loss) gain	71	(3)
Loss recognized related to settlement	0	0
Total recognized in OCI	$ 758	$ (145)