Randy Jackson will step down from 'American Idol' after 12 years as a judge.The 56-year-old music producer - who is the only original judge on the panel of the show - has made the decision not to return next season because he wants to focus on his other interests.He told E! News: "Yo! Yo! Yo! To put all of the speculation to the rest, after 12 years of judging on American Idol I have decided it is time to leave after this season," he says. "I am very proud of how we forever changed television and the music industry. It's been a life changing opportunity but I am looking forward to focusing on my company Dream Merchant 21 and other business ventures."It was recently claimed that bosses at Fox are planning to replace all four judges, Randy, Mariah Carey, Nicki Minaj and Keith Urban with Justin Bieber, Selena Gomez, Pink and Diddy.A source said: "The judges don't have real chemistry, and there's no real stand out contestant."That's why they want to go big next season, and you can't get any bigger than Justin Bieber. The executives are calling it their dream team because who wouldn't tune in to see Justin and Selena, Pink and Diddy? Pink has been approached in the past and turned it down as well as Diddy, who wanted too much money. It will cost a fortune to get them, but the show, has gotten so stale that Fox is desperate for a revamp - they're willing to pay to put 'Idol' back on top."