EMPLOYEE BENEFIT PLANS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4,291	$ 3,699
Interest cost	570	248
Expected return on plan assets	(524)	(138)
Amortization of prior service costs	3	3
Amortization of loss	222	105
Net periodic benefit cost	4,562	3,917
Post Retirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	178	181
Interest cost	93	84
Amortization of prior service costs	(20)	0
Amortization of loss	(5)	0
Net periodic benefit cost	$ 246	$ 265