Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Condensed Consolidated Statements of Operations [Abstract]
Net sales	$ 294,860	$ 244,938	$ 850,216	$ 708,066
Costs and expenses:
Cost of materials (exclusive of depreciation and amortization)	221,690	181,911	631,588	529,469
Warehouse, processing and delivery expense	35,076	30,923	102,092	90,003
Sales, general, and administrative expense	30,060	27,276	92,045	80,026
Depreciation and amortization expense	4,861	4,993	14,919	15,494
Operating income (loss)	3,173	(165)	9,572	(6,926)
Interest expense, net	(1,221)	(1,379)	(3,327)	(3,924)
Income (loss) before income taxes and equity in earnings of joint venture	1,952	(1,544)	6,245	(10,850)
Income taxes (including income taxes on earnings of joint venture)	(1,266)	(43)	(5,000)	2,735
Income (loss) before equity in earnings of joint venture	686	(1,587)	1,245	(8,115)
Equity in earnings of joint venture	3,117	1,659	8,958	3,973
Net income (loss)	$ 3,803	$ 72	$ 10,203	$ (4,142)
Basic income (loss) per share	$ 0.17		$ 0.45	$ (0.18)
Diluted income (loss) per share	$ 0.16		$ 0.44	$ (0.18)
Dividends per common share