Mariah Carey to Join 'American Idol' as a Judge LOS ANGELES - Kevin Reilly, the president of Fox Entertainment, announced Monday that the network had reached a deal with the singing star Mariah Carey to be a judge on the next season of "American Idol." Ms. Carey spoke briefly by a phone to reporters at the annual press tour, saying she was looking forward to joining the show. Mr. Reilly said the deal had just been completed. He also confirmed that Jennifer Lopez had left the show, saying, "I think I can say 100 percent Jennifer is not coming back." Earlier, the show's executive producer, Nigel Lythgoe, had said there was a "1 percent chance" Ms. Lopez would return and suggested that her comments this summer that she would leave might be a "negotiating ploy." Mr. Reilly said Fox had come to a mutual agreement with Ms. Lopez and another judge, Steven Tyler, who previously announced he was leaving the show. But Mr. Reilly said nothing had been decided about the third judge, Randy Jackson. He did note that Mr. Jackson was close to Ms. Carey - he is her co-manager - and was instrumental in recruiting her to join "Idol." Mr. Lythgoe said earlier that he believed it might be best for "Idol" to replace all its judges every season. The blockbuster singing competition suffered through its worst season this year. Bill Carter writes about the television industry. Follow @wjcarter on Twitter.