POSTRETIREMENT MEDICAL BENEFITS Expected Future Cash Flows (Details) (Postretirement Medical Benefits [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Postretirement Medical Benefits [Member]
Expected future payments, postretirement medical benefits:
2015 - Postretirement Medical Benefits	$ 13,263
2016 - Postretirement Medical Benefits	13,572
2017 - Postretirement Medical Benefits	13,889
2018 - Postretirement Medical Benefits	14,299
2019 - Postretirement Medical Benefits	14,663
Years 2020 - 2024 - Postretirement Medical Benefits	76,900
Expected future receipts, Medicare D Subsidy:
2013 - Medicare D Subsidy	(1,239)
2014 - Medicare D Subsidy	(1,284)
2015 - Medicare D Subsidy	(1,340)
2016 - Medicare D Subsidy	(1,390)
2017 - Medicare D Subsidy	(1,434)
Years 2018 - 2022 - Medicare D Subsidy	(7,782)
Expected future payments, net
2013 - Net Postretirement Medical Benefits	12,024
2014 - Net Postretirement Medical Benefits	12,288
2015 - Net Postretirement Medical Benefits	12,549
2016 - Net Postretirement Medical Benefits	12,909
2017 - Net Postretirement Medical Benefits	13,229
Years 2018 - 2022 - Net Postretirement Medical Benefits	$ 69,118

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Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.

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Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.

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