Simon Cowell insisted Monday night that he has no regrets at all about his decision to quit American Idol . Appearing on Larry King's CNN show with the other Idol judges and host Ryan Seacrest to promote Wednesday's Idol Gives Back special, Cowell said that it will not be hard for him to walk away from television's most successful series. He then added, "I've had the best time of my life. I'm very grateful -- as you say, lucky. But you always know when it's the right time to go." When King asked him whether he would miss doing the show, Cowell replied, "I'll probably miss it at times, but you can't keep doing the same thing year after year after year. You can't." At which point fellow judge Ellen Degeneres interjected "No, Larry, you know that." King has been broadcaSting his nightly interview show on CNN since 1985 and has worked as a broadcast interviewer since the late 1950s.