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REVENUE (Deferred Revenue) (Details) - USD ($) $ in Millions | 6 Months Ended |  |  |
--- | --- | --- | --- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Dec. 31, 2018 | Mar. 31, 2018 | Dec. 31, 2017
Deferred Revenue Arrangement [Line Items] |  |  |  |  |
Contract with Customer, Liability, Current | $ 15.5 |  | $ 21.0 | $ 20.0 | $ 23.8
Other Liabilities [Member] |  |  |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |  |  |
Contract with Customer, Liability, Noncurrent | 34.3 |  | $ 38.5 | $ 47.1 | $ 51.4
Other Current Liabilities [Member] |  |  |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |  |  |
Contract With Customer, Liability, Period Increase (Decrease) | (5.5) | $ (3.8) |  |  |
Other Noncurrent Liabilities [Member] |  |  |  |  |
Deferred Revenue Arrangement [Line Items] |  |  |  |  |
Contract With Customer, Liability, Period Increase (Decrease) | $ (4.2) | $ (4.3) |  |  |

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