He has also privately stated he is "not passionate about it anymore" as a reason for leaving the program, sources told TMZ.com.
Lythgoe began working for Idol creator Simon Fuller's 19 Entertainment production company in 2001 and is currently the president of 19 Television.
In addition to executive producing Idol -- which he has done since the Fox mega-hit premiered in June 2002 -- Lythgoe also co-created Fox's So You Think You Can Dance with Fuller.
Now that Idol is apparently out of the picture the 59-year-old plans to focus more of his time and attention on So You Think You Can Dance, for which he serves as executive producer and lead judge.
Lythgoe is also working on another "joint venture" with Fuller, TMZ.com reported.
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