CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues	$ 667,398	$ 645,536	$ 625,705
Cost of sales	474,403	422,031	363,990
Gross profit	192,995	223,505	261,715
Selling, general and administrative expenses	68,447	64,033	62,381
Start-up costs	0	68	184
(Gain) loss on disposal or impairment of assets	(43)	518	1,548
Operating profit	124,591	158,886	197,602
Other income (expense):
Interest income, net	777	64	197
Foreign currency exchange loss, net	(17)	(76)	(135)
Other, net	(150)	(284)	(214)
Nonoperating expense, total	610	(296)	(152)
Income before income taxes	125,201	158,590	197,450
Income taxes	40,315	52,657	67,314
Net income	$ 84,886	$ 105,933	$ 130,136
Earnings per share:
Basic	$ 3.67	$ 4.59	$ 5.62
Diluted	$ 3.67	$ 4.59	$ 5.62