Fast National ratings for Thursday, May 17, 2012.
 
FOX won Thursday night among young viewers as "American Idol" got a solid bump for the season's penultimate results show, while the finales of "Person of Interest" and "The Mentalist" carried CBS to a slim overall victory.
 
Meanwhile, ABC's "Grey's Anatomy" got a big boost for its heavily promoted finale and helped lift "Scandal" to a big finale as well. And NBC's strategy 90 minutes of "Community" yielded better-than-"Awake" numbers, which was probably all the network was hoping for when it swapped shows in the 9 p.m. hour.
 
Among adults 18-49, FOX won Thursday night with a 3.0 rating, tops in the key demographic. ABC averaged a 2.5 rating for second, while CBS' 2.4 rating was close behind in third. There was then a big drop to NBC's 1.1 key demo rating and The CW's 0.3 key demo rating.
 
Overall, though, CBS averaged an estimated 11.37 million viewers and a 7.1 rating/12 share, edging out FOX's 6.8/11 and 11.09 million viewers. ABC was  third with 5.6/9 and 8.39 million viewers. After another huge drop, NBC averaged 2.53 million viewers and a 1.6/3. The CW's 838,000 viewers and 0.6/1 trailed for the night.
 
[Univision averaged 3.72 million viewers and a 1.5 rating among adults 18-49 for Thursday evening.]
 
8 p.m. - FOX's "American Idol" started primetime in first with 15.85 million viewers and a 4.2 rating among adults 18-49 for "American Idol." CBS was a distant second with a repeat of "Big Bang Theory" (8.3 million and a 2.4 key demo) and a new "Rules of Engagement" (7.28 million and a 2.1 key demo). ABC's series finale of "Missing" rose a bit with 6.485 million viewers and a 1.3 key demo rating. NBC was fourth with "Community" (2.99 million and a 1.3 key demo) and the "30 Rock" finale (2.85 million and a 1.3 key demo). The CW aired something linked to Perez Hilton and averaged 965,000 viewers and a 0.3 key demo rating.
 
9 p.m. - The "Person of Interest" finale grabbed first overall for the 9 p.m. hour with 13.35 million viewers, but CBS finished a distant second among adults 18-49 with a 2.5 rating. ABC's "Grey's Anatomy" had a big night with 11.15 million viewers and a 3.9 key demo rating for its finale. FOX's "Touch" slipped to 6.34 million viewers and a 1.8 key demo rating against the touch competition. NBC's two season-closing episodes of "Community" averaged 2.55 million viewers and a 1.3 key demo rating. A repeat of "The Vampire Diaries" averaged 711,000 viewers and a 0.2 key demo rating on The CW.
 
10 p.m. - CBS' season finale of "The Mentalist" averaged 12.96 million viewers and a 2.5 rating among adults 18-49 to win the 10 p.m. hour. ABC's "Scandal" finale was second with 7.52 million viewers and a 2.4 key demo rating. On NBC, "Awake" averaged 2.11 million viewers and a 0.7 key demo rating.

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.