Mariah Carey, Nicki Minaj: Can they get along on 'Idol'?

Apparently, the biggest "American Idol" battle this season will be between new judges Mariah Carey and Nicki Minaj instead of any of the contestants. It's too bad, really, since they actually have a lot in common, including their 2009 duet, "Up Out My Face." Here's a look:

MARIAH CAREY

HAILS FROM Greenlawn

AGE 42

NO. 1 ALBUMS 6 (including 2 of first 3)

BIGGEST HIT "One Sweet Day" (No. 1 for 16 weeks, 1995)

CALLS HER FANS Lambs

TWITTER FOLLOWERS 8.6 million

SEE PHOTOS42 biggest celebrity feuds

JUSTIN BIEBER COLLABO "All I Want for Christmas Is You" duet on his "Under the Mistletoe" album in 2011

JAY-Z COLLABO On remix of her 1999 "Heartbreaker" single

PINK PERFUME LINE(S) Luscious Pink, Ultra Pink

EMINEM RELATIONSHIP Bad -- beefing over a reported failed romance and includes her dis track "Obsessed"

WHY DO "IDOL"? "I just had two babies... and I thought it would be a good thing for me to have something that was a little more stable than just constantly working and whatnot."

NICKI MINAJ

HAILS FROM Jamaica, Queens

AGE 30

NO. 1 ALBUMS 2 (including 2 of first 3)

BIGGEST HIT "Super Bass" (No. 3, 2011)

CALLS HER FANS Barbz

TWITTER FOLLOWERS 15.5 million

JUSTIN BIEBER COLLABO On his 2012 single "Beauty and a Beat"

JAY-Z COLLABO On Kanye West's 2010 single "Monster"

PINK PERFUME LINE(S) Pink Friday

EMINEM RELATIONSHIP Good -- he guests on her Lil' Kim dis track "Roman's Revenge"

WHY DO "IDOL"? "I knew it was going to reach the masses... I always kind of like to do the thing that everybody wouldn't believe I would do, wouldn't expect me to do."