Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Allowance for doubtful accounts receivable	$ 3,269	$ 3,529
Amount current replacement cost of inventory costs exceeded book value	$ 140,303	$ 139,940
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	9,988	9,988
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	60,000	60,000
Common stock, shares issued	23,411	23,211
Common stock, shares outstanding	23,266	23,152
Treasury stock, shares	145	59
Series B Junior Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	400	400