EMPLOYEE BENEFIT PLANS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4,851	$ 3,699	$ 9,142	$ 7,397
Interest cost	601	248	1,171	496
Expected return on plan assets	(539)	(138)	(1,063)	(276)
Amortization of prior service costs	10	3	12	5
Amortization of loss	258	105	480	210
Net periodic benefit cost	5,181	3,917	9,742	7,832
Post Retirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	300	181	478	363
Interest cost	135	84	228	167
Amortization of prior service costs	75	0	55	0
Amortization of loss	1	0	(4)	0
Net periodic benefit cost	$ 511	$ 265	$ 757	$ 530