DIVESTITURE - Summary of Gain (Loss) on Divestiture (Details) - Donhad - Disposed by sale $ in Thousands	Apr. 30, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain from divestiture, before recognition of currency translation loss	$ 4,334
Recognition of cumulative currency translation loss and hedges (out of OCI)	(10,418)
Net pre-tax loss from divestiture of the grinding media business	$ (6,084)

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

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Amount before tax of reclassification adjustment from accumulated other comprehensive income for translation gain (loss) realized upon the sale or liquidation of an investment in a foreign entity and foreign currency hedges that are designated and qualified as hedging instruments for hedges of the foreign currency exposure of a net investment in a foreign operation.

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