Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Cash Flows From Operating Activities
Net income		$ 27,657	$ 21,286
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		18,070	16,127
Deferred compensation	[1]	2,720	1,577
Realized and unrealized (gains) losses on long-term investments		306	(531)
Stock-based compensation		2,423	798
Deferred income taxes		2,683	(1,261)
Other non-cash items		282	(1,397)
Changes in assets and liabilities:
Receivables, net		(36,263)	(11,546)
Inventories		(5,274)	4,969
Other current assets		(315)	(1,703)
Accounts payable and accrued liabilities		(14,846)	5,647
Pension liabilities		156	111
Environmental and legal liabilities		837	90
Deferred revenues		(282)	(195)
Excess tax benefit from stock options and awards		(262)	(120)
Net Cash (Used In) Provided By Operating Activities		(2,108)	33,852
Cash Flows From Investing Activities
Expenditures for property, plant and equipment		(19,340)	(28,295)
Proceeds from sale of product line (Note14)			3,262
Other, net		(3,119)	(73)
Net Cash Used In Investing Activities		(22,459)	(25,106)
Cash Flows From Financing Activities
Revolving debt and bank overdrafts, net		(3,588)	14,241
Other debt repayments		(159)	(2,063)
Dividends paid		(4,237)	(4,047)
Company stock repurchased		(908)
Stock option exercises		258	167
Excess tax benefit from stock options and awards		262	120
Other, net		(235)	(275)
Net Cash (Used In) Provided By Financing Activities		(8,607)	8,143
Effect of Exchange Rate Changes on Cash		2,700	(4,796)
Net Increase (Decrease) in Cash and Cash Equivalents		(30,474)	12,093
Cash and Cash Equivalents at Beginning of Period		176,143	85,215
Cash and Cash Equivalents at End of Period		145,669	97,308
Supplemental Cash Flow Information
Cash (refunds) of income taxes, net of payments		(733)	(2,920)
Cash payments of interest		$ 2,124	$ 435

[1] In the first quarter of 2015, deferred compensation expense was included in administrative expenses. The 2015 amounts have been classified separately to conform to the current year presentation