(in millions) |
2013 | 2012 | |||||
---|---|---|---|---|---|---|---|
Balance at January 1 |
$ | 24 | $ | 37 | |||
Additions for tax positions of prior years |
— | 2 | |||||
Reductions for tax positions of prior years |
(3 | ) | (15 | ) | |||
Additions based on tax positions related to current year |
— | — | |||||
Balance at December 31 |
$ | 21 | $ | 24 | |||