Some 13.5 million viewers tuned in to the Dancing With The Stars results show Tuesday night to see whether Kate Gosselin would finally be the latest star to get the hook. (She was.) The strong numbers for DWTS No Doubt contributed to a decline in viewership for the performance edition of American Idol , which fell below 20 million for the first time in recent memory, attracting 19.1 million viewers. That compares with 24 million who watched the show during the comparable week a year ago. Riding Idol 's coattails was Fox's Glee, which kept 13.5 million or Idol 's viewers.