POSTRETIREMENT MEDICAL BENEFITS Assumptions Used (Details) (Postretirement Medical Benefits [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Weighted-average discount rates used in calculations:
Rate used to determine net periodic benefit cost for the year shown		4.10%	5.15%
Assumed health care trend rates:
Health care cost trend rate assumed for next year	6.75%	7.00%
Rate to which the cost trend is assumed to decline (ultimate trend rate)	5.00%	5.00%
Year that the trend rate reaches the ultimate trend rate	2021	2021
Effect of a 1% change in the health care cost trend rate:
Effect of 1% increase on service and interest cost components	$ 3,148
Effect of 1% decrease on service and interest cost components	(2,442)
Effect of 1% increase on postretirement medical benefit obligation	35,464
Effect of 1% decrease on postretirement medical benefit obligation	$ (30,096)
Minimum [Member]
Weighted-average discount rates used in calculations:
Rate used to determine benefit obligations as of the end of the year shown	4.50%	3.60%
Rate used to determine net periodic benefit cost for the year shown	3.60%
Maximum [Member]
Weighted-average discount rates used in calculations:
Rate used to determine benefit obligations as of the end of the year shown	5.05%	4.15%
Rate used to determine net periodic benefit cost for the year shown	4.15%

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The interest rate used to adjust for the time value of money for the plan.

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- Definition

The interest rate used to adjust for the time value of money.

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Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

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Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

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The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

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The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

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- Definition

The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (l)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Health Care Cost Trend Rate

-URI http://asc.fasb.org/extlink&oid=6514820

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The ultimate trend rate for health care costs.

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- Definition

Year the ultimate health care cost trend rate is expected to be reached, in CCYY format.

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