| Basic and diluted net earnings per share |
The following is a summary of the calculation of basic and diluted net earnings per share. | | | | | | | | | | | | | | | | | | Three Months Ended | | Nine Months Ended | | September 30, | | September 30, | | 2013 | | 2012 | | 2013 | | 2012 | Net income (in millions) | $ | 73 |
| | $ | 72 |
| | $ | 160 |
| | $ | 224 |
| Shares (in thousands): | | | | | | | | Weighted average common shares outstanding | 185,044 |
| | 185,650 |
| | 185,294 |
| | 185,386 |
| Add: Participating securities (a) | 122 |
| | 281 |
| | 165 |
| | 340 |
| Weighted average common shares outstanding — Basic | 185,166 |
| | 185,931 |
| | 185,459 |
| | 185,726 |
| Plus incremental shares from assumed conversions: (b) | | | | | | | | Dilutive effect of stock options | 175 |
| | 186 |
| | 180 |
| | 231 |
| Dilutive effect of restricted stock | 661 |
| | 231 |
| | 547 |
| | 195 |
| Weighted average common shares outstanding — Diluted | 186,002 |
| | 186,348 |
| | 186,186 |
| | 186,152 |
| Basic earnings per share | $ | 0.39 |
| | $ | 0.39 |
| | $ | 0.86 |
| | $ | 1.20 |
| Diluted earnings per share | $ | 0.39 |
| | $ | 0.38 |
| | $ | 0.86 |
| | $ | 1.20 |
|
| | (a) | Restricted stock awards containing rights to non-forfeitable dividends that participate in undistributed earnings with common shareholders are considered participating securities for purposes of computing earnings per share. |
| | (b) | Incremental shares from stock options, restricted stock and performance share units are computed by the treasury stock method. The weighted average shares listed below were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive for the periods presented or were otherwise excluded under the treasury stock method. The treasury stock method calculates dilution assuming the exercise of all in-the-money options and vesting of restricted stock and performance share awards, reduced by the repurchase of shares with the proceeds from the assumed exercises, unrecognized compensation expense for outstanding awards and the estimated tax benefit of the assumed exercises. Performance share units will be included in the treasury stock calculation of diluted earnings per share upon achievement of underlying performance conditions. See Note 15, "Stock-Based Compensation Plans" for further detail on the performance share units. |
| | | | | | | | | | | | | | Three Months Ended | | Nine Months Ended | | September 30, | | September 30, | (in thousands) | 2013 | | 2012 | | 2013 | | 2012 | Stock options | 4,414 |
| | 4,332 |
| | 4,342 |
| | 4,382 |
| Restricted stock | 655 |
| | 876 |
| | 758 |
| | 904 |
| Performance shares | 106 |
| | — |
| | 88 |
| | — |
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