Earnings Per Share

9 Months Ended

Sep. 30, 2012

Earnings (Loss) Per Share [Abstract]

Earnings Per Share [Text Block]

Note C. Earnings Per Share

Earnings per share attributable to the Company's common stockholders is based on the weighted average number of outstanding common shares. Basic earnings (loss) per share excludes the impact of dilutive securities and is computed by dividing net income (loss) attributable to CNA by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock.

For the three and nine months ended September 30, 2012, approximately 450 thousandand 400 thousand potential shares attributable to exercises under stock-based employee compensation plans were included in the calculation of diluted earnings per share. For those same periods, approximately 693 thousandand740 thousand potential shares attributable to exercises under stock-based employee compensation plans were not included in the calculation of diluted earnings per share because the effect would have been antidilutive.

For the three and nine months ended September 30, 2011, approximately 279 thousand and 286 thousand potential shares attributable to exercises under stock-based employee compensation plans were included in the calculation of diluted earnings per share. For those same periods, approximately 1.2 million and 1.1 million potential shares attributable to exercises under stock-based employee compensation plans were not included in the calculation of diluted earnings per share because the effect would have been antidilutive.