POSTRETIREMENT MEDICAL BENEFITS AND PENSION - Pension Benefit Disclosures (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension settlement accounting			$ (814,000)	$ 0
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	500,000	587,000	1,500,000	1,760,000
Interest cost	1,747,000	1,590,000	5,240,000	4,771,000
Expected return on plan assets	(2,154,000)	(2,192,000)	(6,461,000)	(6,577,000)
Amortization of deferred items	359,000	872,000	1,078,000	2,617,000
Total net periodic benefit cost	452,000	857,000	1,357,000	2,571,000
Employer contributions during the period			4,100,000
Cash contributions made by employer during the period			2,200,000
Contributions of company stock made by employer during the period			$ 1,900,000