SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Hedging Activities (Details) $ in Thousands		3 Months Ended					6 Months Ended		12 Months Ended
	Jun. 19, 2018 USD ($)	Sep. 29, 2018 USD ($)	Jun. 30, 2018 USD ($) derivative T	Mar. 31, 2018 USD ($) T	Sep. 30, 2017 USD ($) derivative	Jul. 01, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jul. 01, 2017 USD ($)	Dec. 30, 2017 USD ($)
Derivative [Line Items]
Derivative asset (liabilities)			$ 3,350				$ 3,350		$ (826)
Gain (Loss) on Derivative Used in Net Investment Hedge, Before Tax									5,123
Realized gain on net investment hedge, net of tax									3,150
Derivatives used in Net Investment Hedge, Net of Tax, Period Increase (Decrease)			(2,396)			$ 550	(1,607)	$ 1,076
Realized loss on net investment hedge for grinding media business recorded in earnings			1,215			0	1,215	0
Loss (deferred) on interest rate hedges			(2,467)			0	(2,467)	0
Commodity forward contracts
Derivative [Line Items]
Derivative, notional amount			$ 7,185	$ 7,142			7,185
Derivative, Nonmonetary Notional Amount, Mass | T				1,500
Derivatives used in Net Investment Hedge, Net of Tax, Period Increase (Decrease)				$ 1,345
July - September
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass | T			2,000
October - December
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass | T			1,000
Foreign Currency Forward Contract
Derivative [Line Items]
Derivative, notional amount						$ 44,000		$ 44,000
Derivative, Number Of Instrument Entered | derivative			2		2
Derivative, Term of Contract			2 years		6 months
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax		$ 1,621
Realized loss on net investment hedge for grinding media business recorded in earnings			$ 1,215
Interest Rate Contract [Member]
Derivative [Line Items]
Derivative, notional amount	$ 175,000
Prepaid expenses and other assets | Commodity forward contracts
Derivative [Line Items]
Derivative asset (liabilities)			1,345				1,345		0
Prepaid expenses and other assets | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative asset (liabilities)			2,005				2,005		0
Accrued expenses | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative asset (liabilities)			$ 0				$ 0		$ (826)
Senior Unsecured Notes | Senior Unsecured Notes 5.00% Due 2044
Derivative [Line Items]
Proceeds from Notes Payable	200,000
Stated rate			5.00%				5.00%
Senior Unsecured Notes | Senior Unsecured Notes 5.25% Due 2054
Derivative [Line Items]
Proceeds from Notes Payable	$ 55,000
Stated rate			5.25%				5.25%
Australia, Dollars | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative, notional amount			$ 100,000		$ 24,059		$ 100,000
Derivatives used in Net Investment Hedge, Net of Tax, Period Increase (Decrease)			857
United Kingdom, Pounds | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative, notional amount					$ 21,222
Euro Member Countries, Euro | Foreign Currency Forward Contract
Derivative [Line Items]
Derivative, notional amount			50				$ 50
Derivatives used in Net Investment Hedge, Net of Tax, Period Increase (Decrease)			$ 1,148