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INCOME TAXES - Tax Reform (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2018 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 21, 2017
Income tax |  |  |  |
U.S. federal statutory rate |  | 21.00% |  | 35.00%
Surcharge on the U.S. federal tax rate |  | 10.00% |  |
Percentage of expensing of certain qualified capital investments |  | 100.00% |  |
Percentage of tax on earnings in the form of cash and cash equivalents |  | 15.50% |  |
Percentage of tax on earnings other than in the form of cash and cash equivalents |  | 8.00% |  |
Provision on the deemed repatriation of undistributed foreign earnings adjustment |  | $ 3.2 |  |
Provision for deemed repatriation of undistributed foreign earnings |  |  | $ 7.4 |
Benefit on the remeasurement of the deferred tax assets and liabilities |  |  | $ 18.0 |
Provision on remeasurement of deferred taxes adjustment | $ 0.4 |  |  |
U.S. Virgin Islands |  |  |  |
Income tax |  |  |  |
U.S. federal statutory rate |  | 23.10% | 38.50% |

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