Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues	$ 177,614	$ 149,669	$ 340,780	$ 300,499
Cost of sales	113,361	87,551	213,063	176,325
Gross profit	64,253	62,118	127,717	124,174
Selling, general and administrative expenses	17,056	15,845	33,708	30,132
Start-up costs	6		68
(Gain) loss on disposal or impairment of assets	(59)	(30)	(54)	1,649
Operating profit	47,250	46,303	93,995	92,393
Other income (expense):
Interest income (expense), net	9	56	(35)	100
Foreign currency exchange gain (loss), net	579	(126)	144	(314)
Other, net	47	(53)	(212)	(130)
Nonoperating income (expense), total	635	(123)	(103)	(344)
Income before income taxes	47,885	46,180	93,892	92,049
Income taxes	15,968	16,236	31,684	31,941
Net income	$ 31,917	$ 29,944	$ 62,208	$ 60,108
Earnings per share:
Basic	$ 1.38	$ 1.29	$ 2.69	$ 2.60
Diluted	$ 1.38	$ 1.29	$ 2.69	$ 2.60
Other information:
Dividends declared per common share (See Note 4)			$ 0.48	$ 0.40