"I just felt it was the appropriate thing to do," Carey tells Walters. "Sitting there on the road with two babies, I'm not going to take any chances."
The two divas joined the judges' table for the upcoming season and have had heated words for each other since the announcement was made. Carey claims Minaj threatened her after an argument during an audition in North Carolina, with Minaj reportedly saying, "If I had a gun, I would shoot that bitch."
Minaj has denied making the gun remarks, but Carey seems to be making the best of the situation either way. "For all the drama, I hope it helps the show," she said. "I think it's a classic, classy show and it didn't need this."
Carey will also discuss husband Nick Cannon's recent hospitalization for kidney failure, as well as their 20-month-old twins Monroe and Moroccan.
Regarding Monroe, Carey says, "I call her Miss Monroe, and that kind of dictated her personality. "She's a total diva. She's into jewelry. She's fascinated by jewelry."
Moroccan, who goes by the nickname "Roc," is "more chill."
"He's my pal," Carey says. "He'll just watch movies with me. We've watched 'Shrek' I don't know how many times. We watch movies all the time together, relax."
Carey tells Walters she is trying to stay close to home lately and has made up with Minaj. We'll be able to judge that last sentiment for ourselves next week when "American Idol" returns for its 12th season. In the meantime, Carey's "Nightline" interview airs tonight at 11:35 EST.