EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 10,064	$ 5,790	$ 24,743	$ 17,369
Interest cost	772	710	2,323	2,126
Expected return on plan assets	(1,234)	(830)	(3,447)	(2,489)
Amortization of prior service costs	13	13	39	39
Amortization of loss	328	311	716	933
Net periodic benefit cost	9,943	5,994	24,374	17,978
Post Retirement Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	304	243	743	731
Interest cost	131	134	398	403
Amortization of prior service costs	161	76	379	228
Amortization of loss	0	0	0	0
Net periodic benefit cost	$ 596	$ 453	$ 1,520	$ 1,362