Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016
Cash Flows From Operating Activities
Net income	[1]	$ 59,808	$ 56,420
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		37,729	36,453
Deferred compensation		5,392	5,154
Realized and unrealized gains (losses) on long-term investments		(2,576)	205
Stock-based compensation		4,551	4,448
Deferred income taxes		2,741	6,146
Other non-cash items		2,972	272
Changes in assets and liabilities:
Receivables, net		(33,697)	(33,586)
Inventories		(1,477)	(8,664)
Other current assets		(2,050)	335
Accounts payable and accrued liabilities		(11,777)	8,586
Pension liabilities		(58)	365
Environmental and legal liabilities		(469)	767
Deferred revenues		(162)	(564)
Net Cash Provided By Operating Activities	[2]	60,927	76,337
Cash Flows From Investing Activities
Expenditures for property, plant and equipment		(38,331)	(40,696)
Business acquisition (Note 15)		(4,339)
Other, net		(2,184)	(3,533)
Net Cash Used In Investing Activities		(44,854)	(44,229)
Cash Flows From Financing Activities
Revolving debt and bank overdrafts, net		(7,221)	(3,971)
Other debt repayments		(5,714)	(6,033)
Dividends paid		(9,225)	(8,477)
Company stock repurchased		(1,500)	(2,408)
Stock option exercises		2,518	1,351
Other, net		(1,586)	(235)
Net Cash Used In Financing Activities	[2]	(22,728)	(19,773)
Effect of Exchange Rate Changes on Cash		4,730	1,933
Net Increase (Decrease) in Cash and Cash Equivalents		(1,925)	14,268
Cash and Cash Equivalents at Beginning of Period		225,743	176,143
Cash and Cash Equivalents at End of Period		223,818	190,411
Supplemental Cash Flow Information
Cash payments of income taxes, net of refunds		18,288	11,074
Cash payments of interest		$ 7,101	$ 7,442

[1] The 2016 amounts for the noted items have been immaterially changed from the amounts originally reported as a result of the Company’s fourth quarter 2016 adoption of Accounting Standards Update (ASU) No. 2016-9, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.

[2] The amounts for the six months ended June 30, 2016 have been immaterially changed from the originally reported amounts as a result of the Company’s fourth quarter 2016 adoption of ASU No.2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.