GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION - Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net earnings	$ 6,991	$ 36,666	$ 82,151	$ 123,949
Adjustments to reconcile net earnings to net cash flows from operations:
Depreciation and amortization			62,018	63,500
Noncash (gain) loss on trading securities			(62)	395
Impairment of property, plant and equipment			4,197	0
Impairment of goodwill and intangible assets	15,780	0	15,780	0
Loss from divestiture of grinding media business	0	0	6,084	0
Stock-based compensation			8,076	7,300
Defined benefit pension plan expense			(1,713)	481
Contribution to defined benefit pension plan			(1,555)	(26,064)
Gain on sale of property, plant and equipment			(353)	(732)
Equity in earnings in nonconsolidated subsidiaries	0	0	0	0
Deferred income taxes	(1,686)	(7,268)	814	79
Changes in assets and liabilities:
Net working capital			(96,912)	(43,713)
Other noncurrent liabilities			(1,249)	(1,627)
Income taxes payable (refundable)			(9,223)	(1,732)
Net cash flows from operating activities			68,053	121,836
Cash flows from investing activities:
Purchase of property, plant and equipment			(48,919)	(39,898)
Proceeds from sale of assets			64,786	1,575
Acquisitions, net of cash acquired			(125,309)	(5,362)
Settlement of net investment hedge			(1,621)	5,123
Other, net			(2,371)	(3,462)
Net cash flows from investing activities			(113,434)	(42,024)
Cash flows from financing activities:
Proceeds/(payments) under short-term agreements			3,217	(549)
Proceeds from long-term borrowings			236,936
Principal payments on long-term borrowings			(252,952)	(658)
Settlement of financial derivatives			(2,467)	0
Debt issuance costs			(2,322)	0
Dividends paid			(25,415)	(25,386)
Dividends to noncontrolling interest			(5,737)	(3,895)
Intercompany dividends			0	0
Purchase of noncontrolling interest			(5,510)
Intercompany interest on long-term note				0
Intercompany capital contribution			0	0
Purchase of treasury shares			(86,919)	0
Proceeds from exercises under stock plans			6,376	12,446
Purchase of common treasury shares - stock plan exercises			(1,914)	(3,929)
Net cash flows from financing activities			(136,707)	(21,971)
Effect of exchange rate changes on cash and cash equivalents			(15,095)	23,133
Net change in cash and cash equivalents			(197,183)	80,974
Cash, cash equivalents, and restricted cash—beginning of year			492,805	412,516
Cash, cash equivalents, and restricted cash—end of period	295,622	493,490	295,622	493,490
Eliminations
Cash flows from operating activities:
Net earnings	(13,592)	(38,160)	(92,212)	(100,715)
Adjustments to reconcile net earnings to net cash flows from operations:
Depreciation and amortization			0	0
Noncash (gain) loss on trading securities			0	0
Impairment of property, plant and equipment			0
Impairment of goodwill and intangible assets			0
Loss from divestiture of grinding media business			0
Stock-based compensation			0	0
Defined benefit pension plan expense			0	0
Contribution to defined benefit pension plan			0	0
Gain on sale of property, plant and equipment			0	0
Equity in earnings in nonconsolidated subsidiaries	13,650	37,918	93,426	100,555
Deferred income taxes			0	0
Changes in assets and liabilities:
Net working capital			(1,277)	179
Other noncurrent liabilities			0	0
Income taxes payable (refundable)			0	0
Net cash flows from operating activities			(63)	19
Cash flows from investing activities:
Purchase of property, plant and equipment			0	0
Proceeds from sale of assets			0	0
Acquisitions, net of cash acquired			0	0
Settlement of net investment hedge			0	0
Other, net			63	(19)
Net cash flows from investing activities			63	(19)
Cash flows from financing activities:
Proceeds/(payments) under short-term agreements			0	0
Proceeds from long-term borrowings			0
Principal payments on long-term borrowings			0	0
Settlement of financial derivatives			0
Debt issuance costs			0
Dividends paid			0	0
Dividends to noncontrolling interest			0	0
Intercompany dividends			0	0
Purchase of noncontrolling interest			0
Intercompany interest on long-term note				0
Intercompany capital contribution			0	0
Purchase of treasury shares			0
Proceeds from exercises under stock plans			0	0
Purchase of common treasury shares - stock plan exercises			0	0
Net cash flows from financing activities			0	0
Effect of exchange rate changes on cash and cash equivalents			0	0
Net change in cash and cash equivalents			0	0
Cash, cash equivalents, and restricted cash—beginning of year			0	0
Cash, cash equivalents, and restricted cash—end of period	0	0	0	0
Parent
Cash flows from operating activities:
Net earnings	4,448	35,208	76,689	119,851
Adjustments to reconcile net earnings to net cash flows from operations:
Depreciation and amortization			19,498	19,600
Noncash (gain) loss on trading securities			0	0
Impairment of property, plant and equipment			0
Impairment of goodwill and intangible assets			0
Loss from divestiture of grinding media business			2,518
Stock-based compensation			8,076	7,300
Defined benefit pension plan expense			0	0
Contribution to defined benefit pension plan			0	0
Gain on sale of property, plant and equipment			7	(725)
Equity in earnings in nonconsolidated subsidiaries	(9,609)	(27,953)	(55,487)	(85,274)
Deferred income taxes			729	2,065
Changes in assets and liabilities:
Net working capital			(28,948)	(5,713)
Other noncurrent liabilities			(762)	(381)
Income taxes payable (refundable)			(23,256)	(11,403)
Net cash flows from operating activities			(936)	45,320
Cash flows from investing activities:
Purchase of property, plant and equipment			(16,940)	(14,046)
Proceeds from sale of assets			39	745
Acquisitions, net of cash acquired			(57,805)	0
Settlement of net investment hedge			(1,621)	5,123
Other, net			28,299	15,714
Net cash flows from investing activities			(48,028)	7,536
Cash flows from financing activities:
Proceeds/(payments) under short-term agreements			0	0
Proceeds from long-term borrowings			236,936
Principal payments on long-term borrowings			(252,219)	0
Settlement of financial derivatives			(2,467)
Debt issuance costs			(2,322)
Dividends paid			(25,415)	(25,386)
Dividends to noncontrolling interest			0	0
Intercompany dividends			123,363	22,662
Purchase of noncontrolling interest			0
Intercompany interest on long-term note				0
Intercompany capital contribution			(3,492)	(7,375)
Purchase of treasury shares			(86,919)
Proceeds from exercises under stock plans			6,376	12,446
Purchase of common treasury shares - stock plan exercises			(1,914)	(3,929)
Net cash flows from financing activities			(8,073)	(1,582)
Effect of exchange rate changes on cash and cash equivalents			0	0
Net change in cash and cash equivalents			(57,037)	51,274
Cash, cash equivalents, and restricted cash—beginning of year			83,329	67,225
Cash, cash equivalents, and restricted cash—end of period	26,292	118,499	26,292	118,499
Guarantors
Cash flows from operating activities:
Net earnings	14,792	15,354	70,748	37,784
Adjustments to reconcile net earnings to net cash flows from operations:
Depreciation and amortization			10,564	11,130
Noncash (gain) loss on trading securities			0	0
Impairment of property, plant and equipment			0
Impairment of goodwill and intangible assets			0
Loss from divestiture of grinding media business			0
Stock-based compensation			0	0
Defined benefit pension plan expense			0	0
Contribution to defined benefit pension plan			0	0
Gain on sale of property, plant and equipment			(27)	59
Equity in earnings in nonconsolidated subsidiaries	(4,041)	(9,965)	(37,939)	(15,281)
Deferred income taxes			1,791	0
Changes in assets and liabilities:
Net working capital			(40,255)	(23,364)
Other noncurrent liabilities			387	0
Income taxes payable (refundable)			(1,066)	802
Net cash flows from operating activities			4,203	11,130
Cash flows from investing activities:
Purchase of property, plant and equipment			(9,546)	(5,952)
Proceeds from sale of assets			232	(48)
Acquisitions, net of cash acquired			0	0
Settlement of net investment hedge			0	0
Other, net			(3,683)	(8,985)
Net cash flows from investing activities			(12,997)	(14,985)
Cash flows from financing activities:
Proceeds/(payments) under short-term agreements			0	0
Proceeds from long-term borrowings			0
Principal payments on long-term borrowings			0	0
Settlement of financial derivatives			0
Debt issuance costs			0
Dividends paid			0	0
Dividends to noncontrolling interest			0	0
Intercompany dividends			11,296	0
Purchase of noncontrolling interest			0
Intercompany interest on long-term note				(5,669)
Intercompany capital contribution			3,492	7,375
Purchase of treasury shares			0
Proceeds from exercises under stock plans			0	0
Purchase of common treasury shares - stock plan exercises			0	0
Net cash flows from financing activities			14,788	1,706
Effect of exchange rate changes on cash and cash equivalents			(670)	245
Net change in cash and cash equivalents			5,324	(1,904)
Cash, cash equivalents, and restricted cash—beginning of year			5,304	6,071
Cash, cash equivalents, and restricted cash—end of period	10,628	4,167	10,628	4,167
Non- Guarantors
Cash flows from operating activities:
Net earnings	1,343	24,264	26,926	67,029
Adjustments to reconcile net earnings to net cash flows from operations:
Depreciation and amortization			31,956	32,770
Noncash (gain) loss on trading securities			(62)	395
Impairment of property, plant and equipment			4,197
Impairment of goodwill and intangible assets			15,780
Loss from divestiture of grinding media business			3,566
Stock-based compensation			0	0
Defined benefit pension plan expense			(1,713)	481
Contribution to defined benefit pension plan			(1,555)	(26,064)
Gain on sale of property, plant and equipment			(333)	(66)
Equity in earnings in nonconsolidated subsidiaries	0	0	0	0
Deferred income taxes			(1,706)	(1,986)
Changes in assets and liabilities:
Net working capital			(26,432)	(14,815)
Other noncurrent liabilities			(874)	(1,246)
Income taxes payable (refundable)			15,099	8,869
Net cash flows from operating activities			64,849	65,367
Cash flows from investing activities:
Purchase of property, plant and equipment			(22,433)	(19,900)
Proceeds from sale of assets			64,515	878
Acquisitions, net of cash acquired			(67,504)	(5,362)
Settlement of net investment hedge			0	0
Other, net			(27,050)	(10,172)
Net cash flows from investing activities			(52,472)	(34,556)
Cash flows from financing activities:
Proceeds/(payments) under short-term agreements			3,217	(549)
Proceeds from long-term borrowings			0
Principal payments on long-term borrowings			(733)	(658)
Settlement of financial derivatives			0
Debt issuance costs			0
Dividends paid			0	0
Dividends to noncontrolling interest			(5,737)	(3,895)
Intercompany dividends			(134,659)	(22,662)
Purchase of noncontrolling interest			(5,510)
Intercompany interest on long-term note				5,669
Intercompany capital contribution			0	0
Purchase of treasury shares			0
Proceeds from exercises under stock plans			0	0
Purchase of common treasury shares - stock plan exercises			0	0
Net cash flows from financing activities			(143,422)	(22,095)
Effect of exchange rate changes on cash and cash equivalents			(14,425)	22,888
Net change in cash and cash equivalents			(145,470)	31,604
Cash, cash equivalents, and restricted cash—beginning of year			404,172	339,220
Cash, cash equivalents, and restricted cash—end of period	$ 258,702	$ 370,824	$ 258,702	$ 370,824