Fast National ratings for Thursday, March 29, 2012.
 
You'd have thought it was a sweeps period there was so much ratings action on Thursday night.
 
After a couple weeks away, "The Big Bang Theory" returned to strong numbers and joined forces with "Person of Interest" and "The Mentalist" to give CBS a primetime win on Thursday. However, despite that competition, "American Idol" actually rose and even with a big drop for "Touch," FOX claimed victory among young viewers.
 
Among other Thursday notables: NBC's "Community" remained stable against the new "Big Bang Theory," which has to be a good sign. ABC's "Missing" fell for the second straight week, which has to be a bad sign. And "The Vampire Diaries" and "The Secret Circle" also dropped against the enhanced competition, meaningless for the former, but certainly not encouraging for the latter.
 
For the night, FOX averaged a 3.5 rating among adults 18-49, edging out CBS' 3.2 rating in the key demographic. [CBS and FOX tied in the key demo for the 8-to-10 portion of primetime.] There was a massive drop to NBC's 1.3 rating and to ABC's 1.2 rating and finally to The CW's 0.9 key demo rating.
 
Overall, though, CBS averaged an estimated 13.04 million viewers and an 8.1 rating/13 share, topping FOX's 7.4/12 and 12.2 million viewers. Again, there was a huge drop to third place with ABC averaging 4.91 million viewers and a 3.4/6, but still beating the 2.0/3 and 3.105 million viewers for NBC. The CW averaged 1.85 million viewers and a 1.3/2 for the night.
 
8 p.m. - "American Idol" started primetime in first with 15.27 million viewers and a 4.2 rating among adults 18-49 for its weekly results show. CBS was second with "The Big Bang Theory" (13.64 million viewers and a 4.5 key demo rating, far below its last original airing) and the return of "Rules of Engagement" (8.82 million and a 2.8 key demo rating). ABC's "Missing" was third overall with 7.715 million viewers and fourth with a 1.4 key demo rating. NBC was a distant fourth overall, but third in the key demo with "Community" (down with 3.63 million viewers, but steady with that 1.7 key demo rating) and "30 Rock" (3.2 million viewers and a 1.5 key demo rating). "The Vampire Diaries" averaged 2.36 million viewers and a 1.1 key demo rating.
 
9 p.m. - "Person of Interest" let CBS take over first for the 9 p.m. hour with 14.41 million viewers and a 3.3 rating among adults 18-49. FOX's lost over 2.5 million viewers from last week and averaged 9.13 million and a 2.8 key demo rating (still looking good compared to what "The Finder" was doing post-"Idol"). ABC's repeat of "Grey's Anatomy" was third with 4.21 million viewers and fourth with a 1.2 key demo rating. NBC followed with a repeat of "The Office" (2.6 million and a 1.2 key demo) and a new "Up All Night" (2.95 million and a 1.3 key demo). The CW's "The Secret Circle" averaged only 1.34 million viewers and a 0.6 key demo rating.
 
10 p.m. - "The Mentalist" averaged 13.48 million viewers and a 2.7 key demo rating to dominate the 10 p.m. hour for CBS. The return of "The Mentalist" also took a big bite out of NBC's "Awake," which averaged only 3.13 million viewers and a 1.0 key demo rating, which was a series low, but still better than the 2.81 million viewers and 0.9 key demo rating for a repeat of "Private Practice" on ABC.
 
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.