The following table shows authorized shares and provides a reconciliation of common shares issued and outstanding for the years ended December 31:
(Millions, except where indicated) | 2013 | 2012 | 2011 | ||||
Common shares authorized (billions)(a) | 3.6 | 3.6 | 3.6 | ||||
Shares issued and outstanding at beginning | |||||||
of year | 1,105 | 1,164 | 1,197 | ||||
Repurchases of common shares | (55) | (69) | (48) | ||||
Other, primarily stock option exercises | |||||||
and restricted stock awards granted | 14 | 10 | 15 | ||||
Shares issued and outstanding as of | |||||||
December 31 | 1,064 | 1,105 | 1,164 |