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PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Target Allocation and Actual Asset Allocations for Pension and VEBA Plan Assets) (Details) | 12 Months Ended |
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Dec. 31, 2015 | Dec. 31, 2014
Pension Benefits [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 100.00% | 100.00%
Defined Benefit Plan, Target Plan Asset Allocations | 100.00% |
Pension Benefits [Member] | Equity Securities [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 44.00% | 45.60%
Defined Benefit Plan, Target Plan Asset Allocations | 45.00% |
Pension Benefits [Member] | Fixed Income Investments [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 27.70% | 28.70%
Defined Benefit Plan, Target Plan Asset Allocations | 28.00% |
Pension Benefits [Member] | Hedge Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 5.80% | 5.50%
Defined Benefit Plan, Target Plan Asset Allocations | 5.00% |
Pension Benefits [Member] | Private Equity Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 4.70% | 4.20%
Defined Benefit Plan, Target Plan Asset Allocations | 7.00% |
Pension Benefits [Member] | Structured Finance [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 8.90% | 8.70%
Defined Benefit Plan, Target Plan Asset Allocations | 7.50% |
Pension Benefits [Member] | Real Estate [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 8.20% | 6.70%
Defined Benefit Plan, Target Plan Asset Allocations | 7.50% |
Pension Benefits [Member] | Cash [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 0.70% | 0.60%
Defined Benefit Plan, Target Plan Asset Allocations | 0.00% |
Veba Trust [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 100.00% | 100.00%
Defined Benefit Plan, Target Plan Asset Allocations | 100.00% |
Veba Trust [Member] | Equity Securities [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 8.80% | 8.60%
Defined Benefit Plan, Target Plan Asset Allocations | 8.00% |
Veba Trust [Member] | Fixed Income Investments [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 78.20% | 79.30%
Defined Benefit Plan, Target Plan Asset Allocations | 80.10% |
Veba Trust [Member] | Hedge Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 4.50% | 4.30%
Defined Benefit Plan, Target Plan Asset Allocations | 4.20% |
Veba Trust [Member] | Private Equity Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 2.20% | 2.30%
Defined Benefit Plan, Target Plan Asset Allocations | 2.60% |
Veba Trust [Member] | Structured Finance [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 2.30% | 2.30%
Defined Benefit Plan, Target Plan Asset Allocations | 2.10% |
Veba Trust [Member] | Real Estate [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 4.00% | 3.20%
Defined Benefit Plan, Target Plan Asset Allocations | 3.00% |
Veba Trust [Member] | Cash [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Weighted-average asset allocation | 0.00% | 0.00%
Defined Benefit Plan, Target Plan Asset Allocations | 0.00% |

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- Definition Target allocation of investments of this type to total plan assets presented on a weighted average basis. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c)(i) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2446-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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- Definition Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2446-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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