The following table summarizes the gross unrealized losses on available for sale securities in an unrealized loss position as of June 30, 2014 and December 31, 2013: | | | | | | | | | | | | | | | | | | June 30, 2014 | | Less than or equal to one year | | More than one year | | Fair value | | Gross unrealized losses | | Fair value | | Gross unrealized losses | U.S. Treasury securities and obligations of U.S. government authorities and agencies | $ | 418 |
| | $ | — |
| | $ | 2,092 |
| | $ | (22 | ) | Corporate securities | 533 |
| | (1 | ) | | 234 |
| | (1 | ) | Asset-backed securities | — |
| | — |
| | 2 |
| | — |
| Total | $ | 951 |
| | $ | (1 | ) | | $ | 2,328 |
| | $ | (23 | ) |
| | | | | | | | | | | | | | | | | | December 31, 2013 | | Less than or equal to one year | | More than one year | | Fair value | | Gross unrealized losses | | Fair value | | Gross unrealized losses | U.S. Treasury securities and obligations of U.S. government authorities and agencies | $ | 5,543 |
| | $ | (102 | ) | | $ | 854 |
| | $ | (14 | ) | Corporate securities | 2,253 |
| | (42 | ) | | 67 |
| | — |
| Asset-backed securities | — |
| | — |
| | 2 |
| | — |
| Total | $ | 7,796 |
| | $ | (144 | ) | | $ | 923 |
| | $ | (14 | ) |
|