"American Idol" host Ryan Seacrest is giving some insight into the show's big finale. Seacrest said the show will "celebrate" Katy Perry "all night," as she wraps up seven years of serving as a judge. He said Perry will perform and then will continue celebrating by taking him and the cast members out to eat afterwards. The final episode of "American Idol" Season 22 will air on Sunday at 8 p.m Eastern on ABC.