Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Net sales	$ 218,795	$ 264,654	$ 774,165	$ 757,036
Operating costs and expenses:
Cost of sales	178,305	192,132	592,128	553,888
Selling, general and administrative expenses	24,737	27,453	83,368	76,667
Research and development	7,172	6,947	21,620	19,202
Restructuring charges	10,748	1,102	13,378	5,197
Write down of long-lived assets	15,786		15,786
Net (gain) loss on sales and disposals of assets	9	29	92	(1,406)
Total operating costs and expenses	236,757	227,663	726,372	653,548
Operating income (loss)	(17,962)	36,991	47,793	103,488
Other (income) expense:
Interest income	(62)	(28)	(136)	(133)
Interest expense	7,036	7,756	21,718	22,548
Other (income) expense, net	716	1,471	1,918	(1,647)
Loss on early extinguishment of debt				38,248
Income (loss) before income taxes	(25,652)	27,792	24,293	44,472
Income tax expense	2,119	625	5,897	2,493
Net income (loss)	$ (27,771)	$ 27,167	$ 18,396	$ 41,979
Net income (loss) per share:
Basic (in dollars per share)	$ (0.62)	$ 0.96	$ 0.43	$ 1.53
Diluted (in dollars per share)	$ (0.62)	$ 0.52	$ 0.35	$ 0.82
Weighted-average shares outstanding:
Basic (in shares)	44,644	28,295	42,834	27,464
Diluted (in shares)	44,644	51,960	52,302	51,124