Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating activities
Net income	$ 17,577	$ 30,291
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	11,908	10,604
Provision for doubtful accounts	25
Deferred income taxes	1,059	2,501
Excess tax benefits from stock based compensation	(67)	(1,257)
(Gain) loss on disposal or impairment of assets	(2)	5
Foreign currency transaction loss, net	12	435
Stock compensation expense	1,757	1,682
Changes in operating assets and liabilities:
Trade accounts and other receivables	(5,767)	311
Inventories	(6,893)	(3,781)
Prepaid expenses and other current assets	(542)	150
Long-term prepaid expenses	855	766
Accounts payable	(1,276)	(10,255)
Accrued expenses	(7,727)	(14,881)
Accrued income taxes, net	6,108	12,698
Net cash provided by operating activities	17,027	29,269
Investing activities
Capital expenditures	(13,752)	(26,978)
Net cash used in investing activities	(13,752)	(26,978)
Financing activities
Proceeds from bank borrowings		10,000
Repayments on bank borrowings		(10,000)
Dividends paid	(6,256)	(5,555)
Purchase of common stock	(3,671)	(7,655)
Excess tax benefits from stock based compensation	67	1,257
Net cash used in financing activities	(9,860)	(11,953)
Effect of exchange rate changes on cash	(253)	425
Net decrease in cash and cash equivalents	(6,838)	(9,237)
Cash and cash equivalents at beginning of period	90,635	41,270
Cash and cash equivalents at end of period	83,797	32,033
Supplemental cash flow information
Interest paid	1	7
Income taxes paid	$ 761	$ 517