Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
Cash Flows From Operating Activities
Net income	[1]	$ 81,661	$ 77,787
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		57,121	55,196
Deferred compensation		5,263	12,595
Realized and unrealized gains on long-term investments		(3,677)	(720)
Stock-based compensation		6,248	8,055
Deferred income taxes		7,132	4,169
Other non-cash items		3,738	292
Changes in assets and liabilities:
Receivables, net		(37,713)	(30,270)
Inventories		14,789	(12,485)
Other current assets		(631)	(308)
Accounts payable and accrued liabilities		(5,872)	5,142
Pension liabilities		(2,141)	415
Environmental and legal liabilities		(392)	498
Deferred revenues		(843)	(846)
Net Cash Provided By Operating Activities	[2]	124,683	119,520
Cash Flows From Investing Activities
Expenditures for property, plant and equipment		(57,902)	(69,761)
Business acquisition (Note 15)		(4,339)
Other, net		(759)	(2,788)
Net Cash Used In Investing Activities		(63,000)	(72,549)
Cash Flows From Financing Activities
Revolving debt and bank overdrafts, net		(7,309)	1,014
Other debt repayments		(5,714)	(6,193)
Dividends paid		(13,841)	(12,732)
Company stock repurchased		(4,500)	(2,408)
Stock option exercises		3,127	3,290
Other, net		(1,649)	(275)
Net Cash Used In Financing Activities	[2]	(29,886)	(17,304)
Effect of Exchange Rate Changes on Cash		6,560	1,190
Net Increase in Cash and Cash Equivalents		38,357	30,857
Cash and Cash Equivalents at Beginning of Period		225,743	176,143
Cash and Cash Equivalents at End of Period		264,100	207,000
Supplemental Cash Flow Information
Cash payments of income taxes, net of refunds		22,377	18,577
Cash payments of interest		$ 9,113	$ 9,592

[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 nine months ended September 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.