Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data	Jun. 30, 2011	Dec. 31, 2010
Consolidated Balance Sheets
Accounts receivable, allowances	$ 781	$ 783
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000	2,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	39,865	39,640
Common stock, shares outstanding	31,676	31,495
Treasury stock, shares	8,189	8,145