CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011
Operating Activities:
Consolidated net income	$ 58,030	$ 50,190
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	37,466	43,724
Payments relating to restructuring activities	(826)	(2,360)
Pension plan funding	(11,760)	(4,584)
Tax benefits related to stock incentive programs	270	428
Other non-cash items	6,891	5,799
Net changes in operating assets and liabilities	14,722	(320)
Net cash provided by operating activities	104,793	92,877
Investing Activities:
Purchases of property, plant and equipment	(37,846)	(36,913)
Proceeds from sale of short-term investments	9,310	7,170
Purchases of short-term investments	(4,062)	(8,221)
Net cash used in investing activities	(32,598)	(37,964)
Financing Activities:
Proceeds from issuance of long-term debt	0	1,596
Repayment of long-term debt	(8,280)	0
Net issuance (repayment) of short-term debt	(937)	1,463
Purchase of common shares for treasury	(8,710)	(43,432)
Proceeds from issuance of stock under option plan	6,190	5,078
Excess tax benefits related to stock incentive programs	38	158
Dividends paid to non-controlling interest	(3,394)	0
Cash dividends paid	(2,656)	(2,719)
Net cash used in financing activities	(17,749)	(37,856)
Effect of exchange rate changes on cash and cash equivalents	(492)	(2,356)
Net increase in cash and cash equivalents	53,954	14,701
Cash and cash equivalents at beginning of period	395,152	367,827
Cash and cash equivalents at end of period	449,106	382,528
Supplemental disclosure of cash flow information:
Interest paid	1,791	1,871
Income taxes paid	15,378	22,698
Non-cash financing activities:
Treasury stock purchases settled after period-end	$ 0	$ 1,575