Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating activities
Net income	$ 105,933	$ 130,136	$ 78,716
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	44,893	36,015	27,728
Provision for doubtful accounts	19	229	40
Deferred income taxes	11,212	4,223	2,662
Excess tax benefits from stock based compensation	(1,384)	(1,399)	(759)
Loss on disposal or impairment of assets	518	1,548	1,449
Foreign currency transaction loss, net	76	135	96
Stock compensation expense	5,335	4,719	3,812
Changes in operating assets and liabilities:
Trade accounts and other receivables	8,945	(23,101)	(29,857)
Inventories	(7,589)	(41,704)	(10,818)
Prepaid expenses and other current assets	(150)	(1,142)	(174)
Long-term prepaid expenses	12,005	(24,083)	(14)
Accounts payable	(18,201)	15,971	13,439
Accrued expenses	(10,628)	11,846	8,160
Accrued income taxes, net	5,397	(1,980)	(2,695)
Net cash provided by operating activities	156,381	111,413	91,785
Investing activities
Capital expenditures	(77,189)	(90,395)	(96,566)
Acquisition of BBL Falcon Industries, Ltd.			193
Purchase of short-term investment			(4,989)
Proceeds from maturity of short-term investment			4,989
Net cash used in investing activities	(77,189)	(90,395)	(96,373)
Financing activities
Proceeds from bank borrowings	10,000
Repayments on bank borrowings	(10,000)
Net proceeds from stock based compensation	54	76	254
Dividends paid	(23,563)	(20,369)	(17,570)
Purchase of common stock	(7,927)	(7,550)	(1,904)
Excess tax benefits from stock based compensation	1,384	1,399	759
Net cash used in financing activities	(30,052)	(26,444)	(18,461)
Effect of exchange rate changes on cash	225	40	148
Net increase (decrease) in cash and cash equivalents	49,365	(5,386)	(22,901)
Cash and cash equivalents at beginning of year	41,270	46,656	69,557
Cash and cash equivalents at end of year	90,635	41,270	46,656
Supplemental cash flow information
Interest paid	78	1	2
Income taxes paid	$ 36,036	$ 65,071	$ 40,667