Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts	$ 2,575	$ 2,790
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding at liquidation preference	10,000	10,000
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	190,000,000	190,000,000
Common stock, shares outstanding	87,141,716	79,605,474