| | | | | December 31, 2013 | | December 31, 2012 |
| | | | | | | | | | | | | | | |
| | | | | Amortized | | Fair | | Amortized | | Fair |
| | | | | Cost | | Value | | Cost | | Value |
| | | | | | | | | | | | | | | |
| | | | | (in millions) |
| Short-term investments and cash equivalents | | $ | 697 | | $ | 697 | | $ | 938 | | $ | 938 |
| Fixed maturities: | | | | | | | | | | | | |
| | Corporate securities | | | 12,109 | | | 12,616 | | | 11,076 | | | 12,107 |
| | Commercial mortgage-backed securities | | | 2,417 | | | 2,441 | | | 2,096 | | | 2,229 |
| | Residential mortgage-backed securities(1) | | | 1,857 | | | 1,830 | | | 1,965 | | | 2,026 |
| | Asset-backed securities(2) | | | 1,096 | | | 1,107 | | | 1,179 | | | 1,116 |
| | Foreign government bonds | | | 579 | | | 596 | | | 683 | | | 708 |
| | U.S. government authorities and agencies and obligations of U.S. states | | | 303 | | | 341 | | | 369 | | | 426 |
| Total fixed maturities | | | 18,361 | | | 18,931 | | | 17,368 | | | 18,612 |
| Equity securities | | | 913 | | | 1,199 | | | 943 | | | 1,040 |
| Total trading account assets supporting insurance liabilities | | $ | 19,971 | | $ | 20,827 | | $ | 19,249 | | $ | 20,590 |
