Note 23: Earnings Per Share
We computed our basic and diluted earnings per common share for each period as follows:
(In Millions, Except Per Share Amounts)
Net income available to common stockholders
Weighted average common shares outstanding—basic
Dilutive effect of employee equity incentive plans
Dilutive effect of convertible debt
Weighted average common shares outstanding—diluted
Basic earnings per common share
Diluted earnings per common share
We computed basic earnings per common share using net income available to common stockholders and the weighted average number of common shares outstanding during the period. We computed diluted earnings per common share using net income available to common stockholders and the weighted average number of common shares outstanding plus potentially dilutive common shares outstanding during the period. Net income available to participating securities was insignificant for all periods presented.
Potentially dilutive common shares from employee incentive plans are determined by applying the treasury stock method to the assumed exercise of outstanding stock options, the assumed vesting of outstanding restricted stock units, and the assumed issuance of common stock under the stock purchase plan. Potentially dilutive common shares are determined by applying the if-converted method for our 2005 debentures. However, as our 2009 debentures require settlement of the principal amount of the debt in cash upon conversion, with the conversion premium paid in cash or stock at our option, potentially dilutive common shares are determined by applying the treasury stock method. For further discussion on the specific conversion features of our 2005 and 2009 debentures, see “Note 16: Borrowings.”
In 2013, we excluded on average 55 million outstanding stock options and restricted stock units (29 million in 2012 and 90 million in 2011) from the computation of diluted earnings per common share because these would have been antidilutive. These options could potentially be included in the dilutive earnings per common share calculation in the future if the average market value of the common shares increases and is greater than the exercise price of these options.
In 2013, 2012, and 2011, we included our 2009 debentures in the calculation of diluted earnings per common share because the average market price was above the conversion price. We could potentially exclude the 2009 debentures again in the future if the average market price is below the conversion price.