EMPLOYEE BENEFIT PLANS (Pre-tax Amounts in AOCI Not Yet Recognized as Components of Net Periodic Costs) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service costs	$ (799)	$ (885)
Net actuarial (loss) gain	(24,136)	(22,544)
Total	(24,935)	(23,429)
Post Retirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service costs	(4,691)	(5,337)
Net actuarial (loss) gain	3,981	593
Total	$ (710)	$ (4,744)