| Year ended December 31, | ||||||||
| (in millions) | 2013 | 2012 | 2011 | |||||
| Gross realized gains | $ | 492 | 600 | 1,305 | ||||
| Gross realized losses | (24) | (73) | (70) | |||||
| OTTI write-downs | (183) | (256) | (541) | |||||
| Net realized gains from investment securities | 285 | 271 | 694 | |||||
| Net realized gains from nonmarketable equity investments | 1,158 | 1,086 | 842 | |||||
| Net realized gains from debt securities and equity investments | $ | 1,443 | 1,357 | 1,536 | ||||