Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Allowance on accounts receivable	$ 200,000	$ 450,000
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	52,770,392	55,696,608
Common stock, shares outstanding	52,770,392	55,696,608
Treasury stock, shares	13,363,789	9,556,183