POSTRETIREMENT MEDICAL BENEFITS AND PENSION - Pension Benefit Disclosures (Details) (Pension, USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 500,000	$ 638,000	$ 1,000,000	$ 1,173,000
Interest cost	1,638,000	1,555,000	3,384,000	3,180,000
Expected return on plan assets	(2,154,000)	(2,325,000)	(4,307,000)	(4,385,000)
Amortization of deferred items	359,000	1,004,000	719,000	1,745,000
Total net periodic benefit cost	343,000	872,000	796,000	1,713,000
Cash contributions during the period			1,100,000
Expected contributions during the remainder of 2014			$ 3,200,000