Fox's American Idol rose slightly in the ratings Thursday night and once again became the highest-rated show of the night. Its victory came thanks to its principal rivals, CBS's The Big Bang Theory and Two and a Half Men, airing repeat episodes. Even so, it was a slim victory for Idol, which drew 12.75 million viewers versus 11.15 million for Theory and 8.21 million for Men. Another concern: Fox's Glee, which follows Idol, was able to hold on to just half of Idol's audience, winding up with 6.80 million viewers at 9:00 p.m. A repeat of CBS's Person of Interest, on the other hand, attracted 9.98 million viewers in the same hour.