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PENSIONS AND POSTRETIREMENT BENEFITS (Effect of Fair Value Measurements Using Significant Unobservable Inputs (Level 3) on Changes in Pension Plan Assets) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block] | The following represents the effect of fair value measurements using significant unobservable inputs (Level 3) on changes in plan assets for the years ended December 31, 2014 and 2013:
| (In Millions)
| Year Ended December 31, 2014
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2014 | $ | 57.6 |  |  | $ | 29.1 |  |  | $ | 61.0 |  |  | $ | 40.9 |  |  | $ | 188.6 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | 3.1 |  |  | 3.2 |  |  | 4.4 |  |  | 5.2 |  |  | 15.9 |
Relating to assets sold during the period | (1.5 | ) |  | 3.0 |  |  | — |  |  | — |  |  | 1.5 |
Purchases | — |  |  | 1.4 |  |  | — |  |  | 5.4 |  |  | 6.8 |
Sales | — |  |  | (5.5 | ) |  | — |  |  | (1.5 | ) |  | (7.0 | )
Ending balance — December 31, 2014 | $ | 59.2 |  |  | $ | 31.2 |  |  | $ | 65.4 |  |  | $ | 50.0 |  |  | $ | 205.8 |
| (In Millions)
| Year Ended December 31, 2013
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2013 | $ | 85.6 |  |  | $ | 29.3 |  |  | $ | 56.2 |  |  | $ | 29.4 |  |  | $ | 200.5 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | 4.5 |  |  | (2.1 | ) |  | 33.5 |  |  | 5.1 |  |  | 41.0 |
Relating to assets sold during the period | (1.2 | ) |  | 5.2 |  |  | (28.7 | ) |  | (0.4 | ) |  | (25.1 | )
Purchases | 66.0 |  |  | 14.7 |  |  | 27.5 |  |  | 36.8 |  |  | 145.0 |
Sales | (97.3 | ) |  | (18.0 | ) |  | (27.5 | ) |  | (30.0 | ) |  | (172.8 | )
Ending balance — December 31, 2013 | $ | 57.6 |  |  | $ | 29.1 |  |  | $ | 61.0 |  |  | $ | 40.9 |  |  | $ | 188.6 |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | $ 188.6 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets | $ 200.5 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 15.9 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld | 41.0 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld
Relating to assets sold during the period | 1.5 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod | (25.1)us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod
Purchases | 6.8 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets | 145.0 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets
Sales | (7.0)us-gaap_DefinedBenefitPlanDivestituresPlanAssets | (172.8)us-gaap_DefinedBenefitPlanDivestituresPlanAssets
Fair value of plan assets — end of year | 205.8 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets | 188.6 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Hedge Funds [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 57.6 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember | 85.6 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 3.1 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember | 4.5 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember
Relating to assets sold during the period | (1.5)us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember | (1.2)us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember
Purchases | 0 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember | 66.0 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember
Sales | 0 us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember | (97.3)us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember
Fair value of plan assets — end of year | 59.2 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember | 57.6 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_HedgeFundsMember
Private Equity Funds [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 29.1 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember | 29.3 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 3.2 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember | (2.1)us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember
Relating to assets sold during the period | 3.0 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember | 5.2 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember
Purchases | 1.4 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember | 14.7 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember
Sales | (5.5)us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember | (18.0)us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember
Fair value of plan assets — end of year | 31.2 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember | 29.1 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PrivateEquityFundsMember
Structured Finance [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 61.0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember | 56.2 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 4.4 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember | 33.5 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember
Relating to assets sold during the period | 0 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember | (28.7)us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember
Purchases | 0 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember | 27.5 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember
Sales | 0 us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember | (27.5)us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember
Fair value of plan assets — end of year | 65.4 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember | 61.0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_StructuredFinanceMember
Real Estate [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Roll Forward] |  |
Fair value of plan assets — beginning of year | 40.9 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember | 29.4 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 5.2 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember | 5.1 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsStillHeld / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember
Relating to assets sold during the period | 0 us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember | (0.4)us-gaap_DefinedBenefitPlanActualReturnOnPlanAssetsSoldDuringPeriod / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember
Purchases | 5.4 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember | 36.8 us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember
Sales | (1.5)us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember | (30.0)us-gaap_DefinedBenefitPlanDivestituresPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember
Fair value of plan assets — end of year | $ 50.0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember | $ 40.9 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_RealEstateMember
Veba Trust [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block] | The following represents the effect of fair value measurements using significant unobservable inputs (Level 3) on changes in plan assets for the year ended December 31, 2014 and 2013:
| (In Millions)
| Year Ended December 31, 2014
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2014 | $ | 24.6 |  |  | $ | 6.0 |  |  | $ | 13.5 |  |  | $ | 13.2 |  |  | $ | 57.3 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | 0.5 |  |  | 1.0 |  |  | 0.4 |  |  | 0.9 |  |  | 2.8 |
Relating to assets sold during the period | 0.6 |  |  | 0.4 |  |  | 0.4 |  |  | 0.5 |  |  | 1.9 |
Purchases | — |  |  | 0.1 |  |  | — |  |  | — |  |  | 0.1 |
Sales | (14.2 | ) |  | (1.3 | ) |  | (8.2 | ) |  | (5.9 | ) |  | (29.6 | )
Ending balance — December 31, 2014 | $ | 11.5 |  |  | $ | 6.2 |  |  | $ | 6.1 |  |  | $ | 8.7 |  |  | $ | 32.5 |
| (In Millions)
| Year Ended December 31, 2013
| Hedge Funds |  | Private Equity Funds |  | Structured Credit Fund |  | Real Estate |  | Total
Beginning balance — January 1, 2014 | $ | 23.2 |  |  | $ | 6.2 |  |  | $ | 12.5 |  |  | $ | 15.9 |  |  | $ | 57.8 |
Actual return on plan assets: |  |  |  |  |  |  |  |  |
Relating to assets still held at the reporting date | 2.1 |  |  | 0.2 |  |  | 2.4 |  |  | 2.8 |  |  | 7.5 |
Relating to assets sold during the period | (0.7 | ) |  | 0.4 |  |  | (1.4 | ) |  | (0.7 | ) |  | (2.4 | )
Purchases | 22.5 |  |  | 0.3 |  |  | 11.0 |  |  | 14.2 |  |  | 48.0 |
Sales | (22.5 | ) |  | (1.1 | ) |  | (11 | ) |  | (19.0 | ) |  | (53.6 | )
Ending balance — December 31, 2014 | $ | 24.6 |  |  | $ | 6.0 |  |  | $ | 13.5 |  |  | $ | 13.2 |  |  | $ | 57.3 |

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- Definition Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets. + 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 (b) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=29635418&loc=d3e12355-114930 + Details
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- Definition Tabular disclosure of the effect of fair value measurements using significant unobservable inputs (Level 3) on changes in plan assets of pension plans and/or other employee benefit plans for the period. + 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 (d)(4) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 + Details
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