| PSUs | |||||||||||||||||
| 2013 | 2012 | 2011 | |||||||||||||||
| Weighted- | Weighted- | Weighted- | |||||||||||||||
| Average | Number | Average | Number | Average | Number | ||||||||||||
| Grant Price | of Units | Grant Price | of Units | Grant Price | of Units | ||||||||||||
| Balance at January 1 | $ | 151 | 3,172,201 | $ | 122 | 3,686,991 | $ | 111 | 3,649,288 | ||||||||
| PSUs granted at target | 195 | 869,875 | 185 | 1,004,003 | 154 | 1,055,687 | |||||||||||
| Additional shares earned | |||||||||||||||||
| above target* | 118 | 152,069 | 102 | 550,399 | 118 | 230,524 | |||||||||||
| PSUs released | 118 | (1,321,784) | 102 | (1,998,746) | 118 | (1,189,765) | |||||||||||
| PSUs canceled/forfeited | 170 | (48,067) | 131 | (70,446) | 118 | (58,743) | |||||||||||
| Balance at December 31** | $ | 178 | 2,824,294 | $ | 151 | 3,172,201 | $ | 122 | 3,686,991 | ||||||||
* Represents additional shares issued to employees after vesting of PSUs because final performance metrics exceeded specified targets.
** Represents the number of shares expected to be issued based on achievement of grant date performance targets. The actual number of shares issued depends on the company’s performance against specified targets over the vesting period.