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PENSION AND OTHER POSTRETIREMENT BENEFITS (Effect of Fair Value Measurements Using Significant Unobservable Inputs (Level 3) on Changes in Other Benefit Plan Assets) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | $ 188.1 | $ 169.8
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 5.5 | 15.5
Acquired through business combinations | 5.7 | 6.8
Sales | (8.4) | (7.0)
Fair value of plan assets — end of year | 193.4 | 188.1
Hedge Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 41.5 | 38.8
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | (0.8) | 2.7
Acquired through business combinations | 0.0 | 0.0
Sales | 0.0 | 0.0
Fair value of plan assets — end of year | 40.7 | 41.5
Private Equity Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 31.2 | 29.1
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 1.5 | 3.2
Acquired through business combinations | 5.7 | 1.4
Sales | (7.8) | (5.5)
Fair value of plan assets — end of year | 33.1 | 31.2
Real Estate [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 50.0 | 40.9
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 8.1 | 5.2
Acquired through business combinations | 0.0 | 5.4
Sales | (0.6) | (1.5)
Fair value of plan assets — end of year | 57.5 | 50.0
Other Benefits [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 269.3 | 251.8
Actual return on plan assets: |  |
Fair value of plan assets — end of year | 250.6 | 269.3
Other Benefits [Member] | Hedge Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 11.5 |
Actual return on plan assets: |  |
Fair value of plan assets — end of year | 11.2 | 11.5
Other Benefits [Member] | Private Equity Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 6.2 |
Actual return on plan assets: |  |
Fair value of plan assets — end of year | 5.5 | 6.2
Other Benefits [Member] | Structured Credit [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 6.1 |
Actual return on plan assets: |  |
Fair value of plan assets — end of year | 5.8 | 6.1
Other Benefits [Member] | Real Estate [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 8.7 |
Actual return on plan assets: |  |
Fair value of plan assets — end of year | 10.0 | 8.7
Significant Unobservable Inputs (Level 3) [Member] | Other Benefits [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 32.5 | 57.3
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 1.0 | 2.8
Acquired through business combinations | 0.1 | 0.1
Sales | (1.5) | (29.6)
Fair value of plan assets — end of year | 32.5 | 32.5
Significant Unobservable Inputs (Level 3) [Member] | Other Benefits [Member] | Hedge Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 11.5 | 24.6
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | (0.3) | 0.5
Acquired through business combinations | 0.0 | 0.0
Sales | 0.0 | (14.2)
Fair value of plan assets — end of year | 11.2 | 11.5
Significant Unobservable Inputs (Level 3) [Member] | Other Benefits [Member] | Private Equity Funds [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 6.2 | 6.0
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 0.3 | 1.0
Acquired through business combinations | 0.1 | 0.1
Sales | (1.5) | (1.3)
Fair value of plan assets — end of year | 5.5 | 6.2
Significant Unobservable Inputs (Level 3) [Member] | Other Benefits [Member] | Structured Credit [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 6.1 | 13.5
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | (0.3) | 0.4
Acquired through business combinations | 0.0 | 0.0
Sales | 0.0 | (8.2)
Fair value of plan assets — end of year | 5.8 | 6.1
Significant Unobservable Inputs (Level 3) [Member] | Other Benefits [Member] | Real Estate [Member] |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |
Fair value of plan assets — beginning of year | 8.7 | 13.2
Actual return on plan assets: |  |
Relating to assets still held at the reporting date | 1.3 | 0.9
Acquired through business combinations | 0.0 | 0.0
Sales | 0.0 | (5.9)
Fair value of plan assets — end of year | $ 10.0 | $ 8.7

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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 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930 Reference 2: 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=58740216&loc=d3e1928-114920 + Details
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