Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income	$ 23,737	$ 35,415
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	21,160	21,778
Amortization	6,740	2,702
Deferred income taxes	2,649	5,000
Gain on the sale of property, plant and equipment	(136)	(15)
Asset impairments	121	84
Stock-based compensation expense	3,981	4,020
Excess tax benefit from stock-based compensation	(122)	(340)
Changes in operating assets and liabilities, net of effects from business acquisition:
Accounts receivable	57,044	18,606
Inventories	37,034	(44,446)
Prepaid expenses and other assets	(5,864)	(10,205)
Accounts payable	23,084	3,441
Accrued liabilities	(10,572)	4,895
Income taxes	(1,258)	178
Net cash provided by operations	157,598	41,113
Cash flows from investing activities:
Proceeds from sales of investments at par	200	50
Additions to property, plant and equipment	(15,149)	(24,308)
Proceeds from the sale of property, plant and equipment	188	420
Additions to purchased software	(1,054)	(698)
Other	(83)	19
Net cash used in investing activities	(15,898)	(24,517)
Cash flows from financing activities:
Proceeds from stock options exercised	823	1,471
Excess tax benefits from stock-based compensation	122	340
Principal payments on long-term debt and capital lease obligations	(6,149)	(327)
Share repurchases	(29,315)	(34,558)
Net cash used in financing activities	(34,519)	(33,074)
Effect of exchange rate changes	72	(1,583)
Net increase (decrease) in cash and cash equivalents	107,253	(18,061)
Cash and cash equivalents at beginning of year	465,995	427,376
Cash and cash equivalents at end of period	$ 573,248	$ 409,315