Net Income per Weighted-Average Common Share

9 Months Ended

Sep. 30, 2011

Earnings Per Share [Abstract]

Net Income per Weighted-Average Common Share

5. Net Income per Weighted-Average Common Share

The computations of basic and diluted net income per weighted-average common share for the three and nine-month periods ended September 30, 2011, and 2010, are based on the Company’s weighted-average shares of common stock and potentially dilutive securities outstanding.

Potentially dilutive securities are calculated in accordance with the treasury stock method, which assumes that the proceeds from the exercise of all stock options are used to repurchase the Company’s common stock at the average market price for the period. As of September 30, 2011, and 2010, there were stock options to purchase 2,094,214 and 2,248,119 shares, respectively, of the Company’s common stock outstanding, of which stock options to purchase 1,102,228 and 1,530,410 shares of the Company’s common stock, respectively, were excluded from the computation of diluted net income per weighted-average common share for the quarters ended September 30, 2011, and 2010, respectively, either because the stock options’ exercise prices were greater than the average market price of the Company’s common shares or assumed repurchases from proceeds from the stock options’ exercise were antidilutive.