INCOME TAXES - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income tax expense	$ 8.9	$ 10.6	$ 16.5	$ 19.7
Effective income tax rate	11.30%	18.10%	8.80%	17.40%
Change to Provisional One-Time US Tax Expense on Post 1986 Foreign Earnings			$ 4.5
One Time Provisional US Tax Expense on Post 1986 Foreign Earnings			53.5		$ 58.0
Existing Post 1986 Foreign Earnings Subject to One Time US Tax			1,100.0
Write-Off of Deferred Tax Assets Relating to Officer Compensation			2.8
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 16.0		16.0
German Deferred Tax Assets [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			$ 21.6