Mariah Carey's American Idol salary is in the "ball park" of $18 million.

The superstar diva has been paid a princely sum to appear as a judge on the 12th season of the hit US singing contest.

Mariah discussed her role on the panel and the new chapter in her life she is entering ahead of the series airing next week.

"I think that's in the ball park, but I can't really talk about it," Mariah told Barbara Walters, who mentioned she had read Mariah received $18 million for the role.

"For me ultimately this is about the kids and the contestants. I've been blessed to live my dream for over half my life and I want to give that back to someone else now."

The mother-of-two commented on her famous spat with fellow judge Nicki Minaj, which made the headlines in October last year. Following the explosive confrontation Mariah hired extra security to protect her for the remainder of filming.

“I just felt it was the appropriate thing to do, sitting there on the road with two babies, I’m not going to take any chances," she said during the interview for Nightline on the ABC channel.

"It felt like an unsafe work environment. Whenever someone is reeling threats off to someone else it's not appropriate. I'm a professional. I'm not used to that type of environment."

Barbara asked the singer about Nicki's single Hell Yeah, in which she makes a reference to American Idol and a "b***h" on the show. The Grammy award-winning songstress replied with a cutting critique of Nicki's musical releases.

"[Are you the b***h she's singing about?] I don't know, I don't know I didn't even know she sings," Mariah said. "I thought she rapped or whatever."

The two alpha females have since reconciled and put the disagreement behind them. Mariah hopes the spat with Nicki will not tarnish the show's reputation.

"American idol is a classic, classy show and it didn't need this, it was a crass moment," she humbly explained.

As well as discussing her American Idol role, Mariah spoke about her husband Nick Cannon's kidney failure that resulted in a spell in hospital last year.

"It was very serious but he's got some great doctors who helped him hang in there and really helped him out," Mariah confessed. "He's doing great at the moment."