EMPLOYEE BENEFIT PLANS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,699	$ 2,860	$ 11,096	$ 8,578
Interest cost	248	125	744	376
Expected return on plan assets	(138)	(81)	(414)	(243)
Amortization of prior service costs	3	3	9	8
Amortization of loss	105	8	315	23
Net periodic benefit cost	3,917	2,915	11,750	8,742
Post Retirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	181	205	544	475
Interest cost	84	106	251	296
Net periodic benefit cost	$ 265	$ 311	$ 795	$ 771