I think this is technically not possible. The details of characters can only be seen if you're within a certain range. I don't know exactly how it works but sometimes I have someone's details open and when the person uses a hardline, the window closes. So I assume it has to do with the range of /who, and that you thus can only view the details of someone who's not only online but also within a certain range.
Probably to have less lag because it'll obviously saves us bandwith if we don't load everything. So if we could view the details of offline players we'd have to load so incredibly many data that the system requirements of MXO need to be cranked up.
" width="15" height="15" />
Although this is merely an assumption, I don't think I am that far off how it all works. It makes sense to load only the data that a player can access within his/hers viewing range and not on the other side of the game to save bandwith and RAM space.