Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data	Jun. 30, 2011	Dec. 31, 2010
Current assets
Allowances for accounts receivable	$ 3,278	$ 3,848
Replacement cost, inventories	$ 129,776	$ 122,340
Stockholders' equity
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000	30,000
Common stock, shares issued	23,159	23,149
Common stock, shares outstanding	23,039	22,986
Treasury stock, shares	120	163