CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Activities
Consolidated net income	$ 83,451	$ 76,269	$ 70,254
Loss from discontinued operations	(5,744)	(2,450)	(2,532)
Income from continuing operations	89,195	78,719	72,786
Adjustments to reconcile income from continuing operations to net cash provided by operating activities:
Depreciation, depletion and amortization	47,289	51,124	58,175
Loss on disposal of property, plant and equipment	1,187	1,093	288
Pension amortization and settlement loss	11,836	11,497	7,417
Deferred income taxes	4,421	1,257	1,250
Provision for bad debts	586	1,011	878
Stock-based compensation	5,249	5,476	7,237
Other non-cash items	515	612	41
Changes in operating assets and liabilities
Accounts receivable	(10,460)	(158)	(14,541)
Inventories	(6,534)	6,361	(7,059)
Prepaid expenses and other current assets	706	3,398	(5,787)
Pension plan funding	(11,407)	(16,963)	(6,650)
Accounts payable	(776)	(4,375)	25,426
Restructuring liabilities	(254)	(1,103)	(2,550)
Income taxes payable	(1,505)	3,748	(712)
Tax benefits related to stock incentive programs	485	513	166
Other	7,015	(61)	305
Net cash provided by continuing operations	137,548	142,149	136,670
Net cash used in discontinued operations	(2,751)	(2,231)	(3,011)
Net cash provided by operating activities	134,797	139,918	133,659
Investing Activities
Purchases of property, plant and equipment	(43,831)	(52,130)	(52,060)
Purchases of short-term investments	(5,407)	(5,390)	(12,423)
Proceeds from sales of short-term investments	3,049	9,310	9,380
Proceeds from disposal of property, plant and equipment	28	169	78
Net cash used in investing activities	(46,161)	(48,041)	(55,025)
Financing Activities
Issuance of long-term debt	75,000	0	1,596
Repayment of long-term debt	(77,277)	(8,558)	(275)
Net issuance (repayment) of short-term debt	(1,179)	1,031	2,030
Purchase of common shares for treasury	(51,776)	(25,884)	(48,004)
Cash dividends paid	(6,946)	(4,409)	(3,601)
Proceeds from issuance of stock under option plan	12,108	8,173	5,912
Excess tax benefits related to stock incentive programs	2,303	313	6
Dividends to non-controlling shareholders	(2,445)	(4,645)	0
Net cash used in financing activities	(50,212)	(33,979)	(42,336)
Effect of exchange rate changes on cash and cash equivalents	(2,249)	1,042	(8,973)
Net increase in cash and cash equivalents	36,175	58,940	27,325
Cash and cash equivalents at beginning of year	454,092	395,152	367,827
Cash and cash equivalents at end of year	490,267	454,092	395,152
Non-cash Investing and Financing Activities:
Treasury stock purchases settled after year-end	$ 0	$ 1,771	$ 0