| Schedule of assets measured at fair value on a recurring basis |
The Company’s assets that are measured at fair value on a recurring basis, at September 30, 2012 and December 31, 2011, consist of the following: | | | | | | | | | | | | | | | | | | Fair Value Measurements at Reporting Date Using | At September 30, 2012 | Fair Value | | Quoted Prices in Active Markets for Identical Assets (Level 1) | | Significant Other Observable Inputs (Level 2) | | Significant Unobservable Inputs (Level 3) | Unrestricted | | | | | | | | Available-for-sale marketable securities: | | | | | | | | U.S. government obligations | $ | 368,963 |
| |
|
| | $ | 368,963 |
| |
| U.S. government guaranteed corporate bonds | 57,980 |
| |
|
| | 57,980 |
| |
| Municipal bonds | 26,577 |
| |
|
| | 26,577 |
| |
| Mortgage-backed securities | 91 |
| |
|
| | 91 |
| |
| Equity security | 2,543 |
| | $ | 2,543 |
| |
| |
| | 456,154 |
| | 2,543 |
| | 453,611 |
| |
| | | | | | | | | Restricted | | | | | | | | Available-for-sale marketable securities: | | | | | | | | U.S. government obligations | 8,028 |
| |
|
| | 8,028 |
| |
| | $ | 464,182 |
| | $ | 2,543 |
| | $ | 461,639 |
| |
| | | | | | | | | At December 31, 2011 | | | | | | | | Unrestricted | | | | | | | | Available-for-sale marketable securities: | | | | | | | | U.S. government obligations | $ | 284,819 |
| |
|
| | $ | 284,819 |
| |
| U.S. government guaranteed corporate bonds | 15,316 |
| |
|
| | 15,316 |
| |
| U.S. government guaranteed collateralized mortgage obligations | 622 |
| |
|
| | 622 |
| |
| Municipal bonds | 15,326 |
| |
|
| | 15,326 |
| |
| Mortgage-backed securities | 115 |
| |
|
| | 115 |
| |
| Equity security | 3,019 |
| | $ | 3,019 |
| |
|
| |
| | 319,217 |
| | 3,019 |
| | 316,198 |
| |
| | | | | | | | | Restricted | | | | | | | | Available-for-sale marketable securities: | | | | | | | | U.S. government obligations | 5,940 |
| |
|
| | 5,940 |
| |
| | $ | 325,157 |
| | $ | 3,019 |
| | $ | 322,138 |
| |
|
|