Earnings Per Share
Basic and diluted earnings per share are computed by dividing Net income attributable to common stockholders by the weighted-average common shares outstanding in the period. Diluted earnings per share is computed by giving effect to all potentially dilutive securities that are outstanding. The following table summarizes basic and diluted earnings per share (in millions, except for per share amounts): | | | | | | | | | | | | | | | | | | Three Months Ended | | Six Months Ended | | June 30, 2015 | | June 30, 2014 | | June 30, 2015 | | June 30, 2014 | Basic earnings per share | | | | | | | | Net income attributable to stockholders | $ | 1,117 |
| | $ | 278 |
| | $ | 2,062 |
| | $ | 491 |
| Less: cumulative dividends on Series A preferred stock(a) |
| | (88 | ) | |
| | (176 | ) | Net income attributable to common stockholders | $ | 1,117 |
| | $ | 190 |
| | $ | 2,062 |
| | $ | 315 |
| | | | | | | | | Weighted-average common shares outstanding | 1,596 |
| | 1,608 |
| | 1,606 |
| | 1,598 |
| Basic earnings per common share | $ | 0.70 |
| | $ | 0.12 |
| | $ | 1.28 |
| | $ | 0.20 |
| Diluted earnings per share | | | | | | |
| Net income attributable to common stockholders – basic | $ | 1,117 |
| | $ | 190 |
| | $ | 2,062 |
| | $ | 315 |
| Less: earnings adjustment for dilutive stock compensation rights | (4 | ) | | — |
| | (1 | ) | | (14 | ) | Net income attributable to common stockholders – diluted | $ | 1,113 |
| | $ | 190 |
| | $ | 2,061 |
| | $ | 301 |
| | | | | | | | | Weighted-average common shares outstanding – basic | 1,596 |
| | 1,608 |
| | 1,606 |
| | 1,598 |
| Dilutive effect of warrants and restricted stock units (RSUs) | 64 |
| | 80 |
| | 67 |
| | 91 |
| Weighted-average common shares outstanding – diluted | 1,660 |
| | 1,688 |
| | 1,673 |
| | 1,689 |
| | | | | | | | | Diluted earnings per common share | $ | 0.67 |
| | $ | 0.11 |
| | $ | 1.23 |
| | $ | 0.18 |
|
________ | | (a) | Includes earned but undeclared dividends of $15 million on our Series A preferred stock in the three and six months ended June 30, 2014. |
In the three and six months ended June 30, 2015 and 2014 warrants to purchase 46 million shares were not included in the computation of diluted earnings per share because the warrants' exercise price was greater than the average market price of the common shares. |