Unaudited Condensed Consolidated Balance Sheets Parenthetical (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
Current Assets:
Allowance for doubtful accounts	$ 1,164	$ 1,090
Stockholders' Equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued and outstanding	64,155,606	63,652,228
Preferred Stock [Member]
Stockholders' Equity:
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred Stock Series A Junior Participating [Member]
Stockholders' Equity:
Preferred stock, shares authorized	75,000	75,000