Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income	$ 44,375	$ 45,479
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	27,452	31,623
Amortization	9,139	10,379
Deferred income taxes	1,505	2,577
Gain on the sale of property, plant and equipment	(194)	(119)
Asset impairments	42	121
Stock-based compensation expense	6,819	4,302
Excess tax benefit from stock-based compensation	0	(299)
Changes in operating assets and liabilities, net of effects from business acquisitions:
Accounts receivable	30,926	61,776
Inventories	(38,778)	13,991
Prepaid expenses and other assets	(12,066)	(302)
Accounts payable	3,922	59,183
Accrued liabilities	15,637	19
Income taxes	1,111	(146)
Net cash provided by operations	89,890	228,584
Cash flows from investing activities:
Proceeds from sales of investments at par	250	200
Additions to property, plant and equipment	(35,033)	(24,126)
Proceeds from the sale of property, plant and equipment	270	237
Additions to purchased software	(2,703)	(1,272)
Business acquisitions, net of cash acquired	0	10,750
Other	(156)	(224)
Net cash used in investing activities	(37,372)	(14,435)
Cash flows from financing activities:
Proceeds from stock options exercised	9,828	5,544
Employee taxes paid for shares withheld	(383)	(554)
Excess tax benefits from stock-based compensation	0	299
Principal payments on long-term debt and capital lease obligations	(9,288)	(9,224)
Share repurchases	(5,887)	(40,862)
Debt issuance costs	(433)	0
Net cash used in financing activities	(6,163)	(44,797)
Effect of exchange rate changes	2,358	336
Net increase in cash and cash equivalents	48,713	169,688
Cash and cash equivalents at beginning of year	681,433	465,995
Cash and cash equivalents at end of period	$ 730,146	$ 635,683