TV Ratings: 'Community' plummets, 'Zero Hour' fizzles and 'Big Bang Theory' leads CBS on slow Thursday

Fast National rating for Thursday, February 14, 2013.   With TV viewership levels down on Valentine's Day, there was ample bad news to go around, with "Community" plunging, "Zero Hour" underperforming and "American Idol" continuing to slide. Even "The Big Bang Theory" dropped, though not so much that it didn't lead CBS to comfortable Thursday wins.   With viewership levels returning to normal in late-evening, the only shows that weren't down on Thursday were 10 p.m. dramas "Scandal" and "Elementary." Of note, "Scandal" actually built on its "Grey's Anatomy" lead-in among young viewers for the first time.