Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Allowance on accounts receivable	$ 200,000	$ 200,000
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	50,748,873	52,770,392
Common stock, shares outstanding	50,748,873	52,770,392
Treasury stock, shares	16,412,755	13,363,789