| | | | December 31, | | December 31, |
| (Millions) | | 2013 | | 2012 |
| | | | | | |
| U.S. government agency securities | | $ | 103 | | $ | 162 |
| Foreign government agency securities | | | 30 | | | 16 |
| Corporate debt securities | | | 143 | | | 471 |
| Commercial paper | | | 60 | | | 116 |
| Certificates of deposit/time deposits | | | 20 | | | 41 |
| U.S. treasury securities | | | ― | | | 54 |
| U.S. municipal securities | | | 2 | | | 13 |
| Asset-backed securities: | | | | | | |
| | Automobile loan related | | | 287 | | | 567 |
| | Credit card related | | | 52 | | | 123 |
| | Equipment lease related | | | 30 | | | 54 |
| | Other | | | 29 | | | 31 |
| Asset-backed securities total | | | 398 | | | 775 |
| | | | | | | | |
| Current marketable securities | | $ | 756 | | $ | 1,648 |
| | | | | | | | |
| U.S. government agency securities | | $ | 131 | | $ | 125 |
| Foreign government agency securities | | | 95 | | | 51 |
| Corporate debt securities | | | 638 | | | 494 |
| Certificates of deposit/time deposits | | | 20 | | | ― |
| U.S. treasury securities | | | 49 | | | 18 |
| U.S. municipal securities | | | ― | | | 14 |
| Auction rate securities | | | 11 | | | 7 |
| Asset-backed securities: | | | | | | |
| | Automobile loan related | | | 298 | | | 375 |
| | Credit card related | | | 128 | | | 34 |
| | Equipment lease related | | | 37 | | | 36 |
| | Other | | | 46 | | | 8 |
| Asset-backed securities total | | | 509 | | | 453 |
| | | | | | | | |
| Non-current marketable securities | | $ | 1,453 | | $ | 1,162 |
| | | | | | | | |
| Total marketable securities | | $ | 2,209 | | $ | 2,810 |
