Consolidated Statements of Operations (Unaudited) (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
Consolidated Statements of Operations [Abstract]
Net revenues	$ 43,451	$ 40,571	$ 136,355	$ 159,692
Costs and expenses:
Cost of sales	36,657	33,077	119,257	136,492
Other operating costs and expenses	306	567	995	1,578
Selling, general and administrative expenses	2,025	1,945	6,094	5,919
Total costs and expenses	38,988	35,589	126,346	143,989
Operating income	4,463	4,982	10,009	15,703
Interest income, net	10	10	40	24
Gain on sale of building	347		347
Realized gain on sale of marketable security		966	828	966
Income before income taxes	4,820	5,958	11,224	16,693
Provision for income taxes	1,649	1,774	2,953	3,407
Net income	$ 3,171	$ 4,184	$ 8,271	$ 13,286
Net income per share:
Basic	$ 0.12	$ 0.15	$ 0.30	$ 0.49
Diluted	$ 0.12	$ 0.15	$ 0.30	$ 0.49
Weighted average shares outstanding:
Basic	27,130	27,130	27,130	27,130
Diluted	27,130	27,131	27,130	27,131