Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues	$ 645,536	$ 625,705	$ 473,082
Cost of sales	422,031	363,990	298,411
Gross profit	223,505	261,715	174,671
Selling, general and administrative expenses	64,033	62,381	52,635
Start-up costs	68	184	977
Loss on disposal or impairment of assets	518	1,548	1,449
Operating profit	158,886	197,602	119,610
Other income (expense):
Interest income, net	64	197	178
Foreign currency exchange loss, net	(76)	(135)	(96)
Other, net	(284)	(214)	(343)
Nonoperating expense, total	(296)	(152)	(261)
Income before income taxes	158,590	197,450	119,349
Income taxes	52,657	67,314	40,633
Net income	$ 105,933	$ 130,136	$ 78,716
Earnings per share:
Basic	$ 4.59	$ 5.62	$ 3.41
Diluted	$ 4.59	$ 5.62	$ 3.40