Condensed Consolidated Statement Of Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statement Of Comprehensive Income [Abstract]
Revenues	$ 39,697	$ 56,402
Cost of sales	30,805	40,709
Gross profit	8,892	15,693
Selling, general, and administrative expense	5,518	4,851
Research and development expense	601	485
Other proceeds/gains resulting from natural disaster, net - 2005 storms
Gain on disposal of assets	(397)	(18)
Operating income	3,170	10,375
Interest income	7	18
Interest expense	(396)	(614)
Other expense, net	(86)	(60)
Income before income taxes	2,695	9,719
Provision for income taxes	865	3,765
Net income	1,830	5,954
Other comprehensive income (loss):
Energy swap adjustment, net of tax expense of $394 and $951, respectively	731	1,847
Pension benefits adjustment, net of tax expense of $133 and $100, respectively	247	194
Comprehensive income	$ 2,808	$ 7,995
Basic earnings per share	$ 0.09	$ 0.32
Weighted average common shares outstanding	19,595	18,879
Diluted earnings per share	$ 0.09	$ 0.30
Weighted average common shares and potential common share equivalents outstanding	20,075	19,565