Fast National ratings for Thursday, February 24, 2011.
 
Although neither hour of FOX's "American Idol" reached the ratings for the previous Thursday's one-hour telecast, the singing talent show still drew a big audience as the Top 12 Men and Top 12 Women were announced.
 
In addition to boosting FOX to nightly wins, "Idol" played no small part in impressively low ratings for "Grey's Anatomy" and "CSI."
 
For the night, FOX averaged a 7.2 rating among adults 18-49, easily tops in the key demographic. CBS Was a distant second with a 3.0 rating, followed closely by a 2.6 rating for ABC and NBC's 2.1 rating. The CW's 1.0 rating was fifth.
 
Overall, FOX averaged an estimated 21.58 million viewers and an 11.9 rating/19 share for the night. CBS was second with a 7.8/13 and 12.74 million viewers. Third place ABC was pretty far back with a 4.8/8 and 7.63 million viewers, easily topping the 2.5/4 and 4.27 million for NBC. The CW was down from last week with a 1.4/2 and 2.465 million viewers.
 
8 p.m. - "American Idol" started primetime in first with 21.34 million viewers and a 7.0 rating among adults 18-49 for FOX. CBS was second with "The Big Bang Theory" (12.51 million and a 3.8 demo) and the time period premiere of "Rules of Engagement" (9.63 million and a 2.8 demo), which was in line with recent performances from "$#*! My Dad Says." ABC's "Wipeout" averaged 7.09 million viewers and a 2.2 demo rating for third. NBC was fourth with "Community" (3.91 million and a 1.8 demo) and "Perfect Couples" (2.96 million and a 1.4 demo). The CW's "The Vampire Diaries" was fifth with 2.94 million viewers and a 1.3 demo rating.
 
9 p.m. - The second hour of "American Idol" improved to 21.82 million viewers and a 7.3 demo rating for FOX. CBS was second overall, but fourth in the demo with the 12.48 million viewers and 2.7 demo rating for "CSI: Crime Scene Investigation." ABC's "Grey's Anatomy" had a low week with 9.095 million viewers and only a 3.3 rating in the key demo. NBC's "The Office" (6.02 million and a 3.3 demo) and "Parks and Recreation" (4.65 million and a 2.4 demo rating) combined for third in the demo and fourth overall. The CW was fifth with the 1.99 million viewers and 0.8 demo rating for "Nikita."
 
10 p.m. - "The Mentalist" moved into first for CBS in the 10 p.m. hour with 14.67 million viewers and a 2.8 demo rating. ABC was second with the 6.7 million viewers and 2.4 demo rating for "Private Practice." NBC trailed with "30 Rock" (4.51 million viewers and a 2.3 demo) and "Outsourced" (3.395 million and a 1.5 demo).
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.