The following table presents the total unrecognized compensation expense related to stock-based compensation and the expected weighted average period over which these expenses will be recognized at:
|
| | | | | |
| December 31, 2013 |
| Expense | | Weighted Average Period |
| (In millions) | | (Years) |
Stock Options | $ | 25 |
| | 1.27 |
Performance Shares | $ | 61 |
| | 1.71 |
Restricted Stock Units | $ | 42 |
| | 1.88 |
