Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts receivable	$ 719	$ 882
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	100,000	100,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000	150,000
Common stock, shares issued	48,428	48,144
Common stock, shares outstanding	48,428	48,144
Treasury stock, shares	385	385