Earnings Per Share | 9 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Earnings Per Share [Abstract] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Earnings Per Share | 13. Earnings per share The Company calculates earnings per share in accordance with FASB guidance on Earnings per share. Basic and diluted earnings per common share give effect to the change in the number of common shares of the Company. The calculation of earnings per common share was determined by dividing net income available to common shareholders by the weighted average number of common shares outstanding during the respective periods. The potentially dilutive shares, consisting of outstanding options on common shares, restricted share units, common shares to be issued under employee stock purchase plan and performance units have been included in the computation of diluted net earnings per share and the weighted average shares outstanding, except where the result would be anti-dilutive. The number of stock options outstanding but not included in the computation of diluted earnings per common share because their effect was anti-dilutive is 9,585,407 and 7,078,561 for the nine months ended September 30, 2010 and 2011, respectively, and is 8,752,810 and 6,561,228 for the three months ended September 30, 2010 and 2011, respectively.
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