Primetime Ratings: 'American Idol' Marks Biggest Between-Season Drop Yet

Wednesday night's tenth season premiere of Fox's American Idol marked a big ratings drop, but the news wasn't all bad for Fox.

The show drew 26.1 million viewers, down 13% from last year's Tuesday debut (29.9 million), and posted a 9.7 preliminary adults 18-49 rating, down 18% from that premiere (11.8).

While the numbers were off from last year, it's not time to hit the panic button at Fox, given the show is in its tenth season, debuted for the first time without star Simon Cowell, on a new night and has an almost completely new cast this season. And the show did gain viewers as the night went on.

That said, the drop with the key adult demo marks Idol's lowest-rated premiere since its 2002 summer debut and the series' biggest drop to date between seasons.

The show's largest slides last night were among younger viewers, with teen viewership down 28% from the 2010 opener.

Overall, Fox won the night in the 18-49 demo. ABC was runner-up with an overall 2.7/7, mostly down against its competition from Idol. The Middle was down 10% vs. last week to a 2.7 with adults 18-49, while Better With You fell 12% from its last new episode on Jan. 5 to a 2.2 rating. Modern Family was up 10% to a 4.6 Wednesday night after last week's Tucson memorial service scrambled last week's numbers. Cougar Town slid 11% to a 2.5, vs. its last new episode Jan. 5. Though newcomer Off the Map slid a modest 9% from last week's premiere, it nonetheless marked a bleak 2.1 rating with adults 18-49.

CBS took third with an overall 1.9/5 and a generally anemic performance by is lineup. Former Idol judge Paula Abdul's Live to Dance plummeted 33% to a 1.0 rating with the key adults demo. Criminal Minds was down 15% from its last new episode in December to a 2.8 and Blue Bloods' Wednesday time slot premiere drew a 2.0 rating, just 11% above the show's Friday night average.

NBC followed, posting a 1.6/4 for the night. Minute To Win It was up 14% to a 1.6 rating after last week's Tucson overrun. Chase struggled in its new Wednesday timeslot premiere with a 1.0 rating with key adults, while Law & Order:SVU was down 8% from last week to a 2.3.

The CW rounded out the night with repeats, marking an overall 0.4/1.