Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash Flows From Operating Activities
Net income	$ 83,914	$ 63,382
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	45,311	40,329
Deferred compensation	3,652	(859)
Realized and unrealized gains on long-term investments	(2,761)	(75)
Stock-based compensation	5,346	4,191
Deferred income taxes	(39,475)	1,427
Other non-cash items	92	655
Changes in assets and liabilities:
Receivables, net	(68,033)	(23,253)
Inventories	(35,747)	(9,740)
Other current assets	(63)	(6,077)
Accounts payable and accrued liabilities	34,027	(8,284)
Pension liabilities	(971)	(323)
Environmental and legal liabilities	(463)	(3,116)
Deferred revenues	(134)	243
Net Cash Provided By Operating Activities	24,695	58,500
Cash Flows From Investing Activities
Expenditures for property, plant and equipment	(74,868)	(54,671)
Asset acquisition (Note 17)	(3,503)	(2,040)
Business acquisition, net of cash acquired (Note 17)	(184,560)
Other, net	1,430	2,331
Net Cash Used In Investing Activities	(261,501)	(54,380)
Cash Flows From Financing Activities
Revolving debt and bank overdrafts, net (Note 14)	4,495
Other debt borrowings (Note 14)	50,000
Other debt repayments	(14,286)	(14,286)
Dividends paid	(13,724)	(12,371)
Company stock repurchased	(10,895)	(13,753)
Stock option exercises	1,087	392
Other, net	(1,920)	(415)
Net Cash (Used In) Provided By Financing Activities	14,757	(40,433)
Effect of Exchange Rate Changes on Cash	(836)	(6,193)
Net Decrease in Cash and Cash Equivalents	(222,885)	(42,506)
Cash and Cash Equivalents at Beginning of Period	349,938	315,383
Cash and Cash Equivalents at End of Period	127,053	272,877
Supplemental Cash Flow Information
Cash payments of income taxes, net of refunds/payments	43,472	7,501
Cash payments of interest	$ 4,622	$ 4,810