Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Current Assets:
Allowance for doubtful accounts receivable	$ 555	$ 515
Stockholders' Equity:
Preferred stock, par value	$ 10.00	$ 10.00
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	175,000,000	175,000,000
Common stock, shares issued	60,807,913	60,460,782
Treasury stock, Shares	11,596,966	11,589,603