Related Video: Minaj and Urban named new Idol judges
The Fox network (US) officially tapped the pair with an announcement on Sunday, confirming rumours surrounding them both just hours before the first round of auditions for next season was due to begin in New York.
The announcement came just days after Urban had turned his back on hit Australian show The Voice saying only that "as much as I’d love to do it again, it’s clear that the recording and promoting of a new album, a tour and other commitments, will keep me from being a part of the second season."
The Idol announcement also settled the status of Randy Jackson. He will stay put as the sole remaining original Idol judge, scotching rumours he might assume a different role on the popular talent competition.
This trio will join pop star Mariah Carey on a judges' panel now expanded to four members from its previous three.
Arriving at Lincoln Center, where the auditions would take place, Urban hailed Idol for its "great history of producing real stars".
As an Idol judge, he said he plans to be "authentic" but not cruel.
"I did similar shows when I was very young in Australia," he recalled, "and I was sort of crucified by one judge. So I don't know that I'll ever be that guy."
Minaj said that during the auditions she'll be looking for "a superstar", which, she explained, is "something that can't be defined in words".
Related Video: Mariah worried that Nicki Minaj will upstage her
Jackson called this pair of hires a "fresh, fresh, fresh Idol one-two!"
Minaj, he said, "brings a whole other cool vibe we've never had on the show, and Keith Urban? My God, he's unbelievably talented!"
When Carey was asked whether she had eagerly awaited news of who would join her as judges, she cracked that, no, she hadn't, "because all I really care about is me," but quickly added, "Only kidding."
Turning serious, she said she didn't know what kind of judge she would be.
"Am I the mean one? Am I the nice one? ... It's not about me, me, me, it's about them (the contestants) and what I can bring to them to help guide them in the right direction," said Carey.
Ryan Seacrest will remain as host when the show returns for its 12th season in January.
"Last night," he said, "we had a chance to really get together for the first time as a group. Everybody made a toast and talked about how special it was that they were here, and why they were here. So we're off to a good start."
Seacrest took note of "the serious and obvious diversity on this panel," adding, "You can see just by the panel the kind of power the show has."
The makeup of the panel has been in flux since Steven Tyler and Jennifer Lopez announced their exits in July. Carey signed on later that month.
Related Video: Mariah confirmed as Idol judge