Tyler said the group plans to release a new album Nov. 6.
"After some long... hard... thoughts... I've decided it's time for me to let go of my mistress 'American Idol' before she boils my rabbit," Tyler said in a statement Thursday -- referring to a scene in the movie "Fatal Attraction" in which a jilted lover boils an adulterer's pet bunny.
"I strayed from my first love, Aerosmith, and I'm back -- but instead of begging on my hands and knees, I got two fists in the air and I'm kicking the door open with my band. 'Idol' was over-the-top fun, and I loved every minute of it. ... Now it's time to bring rock back."
"Steven Tyler is a real 'Idol,' a rock legend," executive producer Simon Fuller said in a separate statement. "If you had told me 10 years ago he would be a judge on 'American Idol,' I would have thought it impossible. ... I completely understand his desire to get back to his life as the singer in America's greatest-ever rock band. 'American Idol' will miss him!"