After getting his feet wet critiquing contestants Down Under on The Voice Australia, Keith Urban dives headfirst into American television as the fourth judge on American Idol, joining pop superstar Mariah Carey, hip-hop queen Nicki Minaj and Idol cornerstone Randy Jackson at the judges table. 

The possibility of Keith signing on to the Fox singing competition was in the air for weeks, but it wasn't made official until this weekend. 

"It's really an honor to have been invited to be a part of the American Idol family," Keith said. "I'm looking forward to working with everyone and to seeing the same passion that I have for music in all of the participants."

Keith and Nicki will join returning judge Randy, the recently signed Mariah and host Ryan Seacrest in New York City on Sunday (Sept. 16), where auditions begin, before heading off to Los Angeles; Chicago; Charlotte, N.C.; San Antonio; Baton Rouge, La.; and Oklahoma City.

The series' 12th season is slated to premiere in January.