| The following table summarizes activity in the reserve for representation and warranty provisions: | ||||
| ($ in millions) | 2013 | 2012 | ||
| Balance, beginning of period | $ | 110 | 55 | |
| Net additions to the reserve | 7 | 107 | ||
| Losses charged against the reserve | (73) | (52) | ||
| Balance, end of period | $ | 44 | 110 | |