EMPLOYEE BENEFIT PLANS (Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 47,344	$ 40,572	$ 36,359
Interest cost	5,793	4,336	3,096
Expected return on plan assets	(8,540)	(5,766)	(4,681)
Settlement loss recognized	0	993	0
Amortization of prior service costs	85	53	53
Amortization of actuarial loss	285	452	1,043
Net periodic benefit cost	44,967	40,640	35,870
Post Retirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,148	1,263	1,047
Interest cost	620	688	528
Expected return on plan assets	0	0	0
Settlement loss recognized	0	0	0
Amortization of prior service costs	646	646	541
Amortization of actuarial loss	0	0	0
Net periodic benefit cost	$ 2,414	$ 2,597	$ 2,116