Green Day is an American punk rock band formed in 1987 consisting of Billie Joe Armstrong, Tre Cool, and Mike Dirnt. The band has released 8 albums from 1990 to 2009, including their breakthrough albums Dookie and American Idiot. American Idiot, released in 2004, sold over 14 million copies worldwide and won a Grammy for Best Rock Album, as did their 2009 album 21st Century Breakdown which sold more than 3.5 million copies worldwide.