Mariah Carey and Nicki Minaj's drama-filled antics on American Idol have failed to keep the struggling show afloat - the talent contest captured its smallest ever audience for finale performances on Wednesday (15May2013).

The singing competition's latest line-up of judges - Carey, Minaj, Keith Urban and Randy Jackson - have struggled to make their mark with U.S. viewers, with only 11.57 million people tuning in to watch season 12's finalists battle it out to win.

The series has lost more than two million viewers a night compared to season 11. The previous low for a final performance was registered last year (12) with a 4.2 rating compared to Wednesday's 2.9 score.

Idol's ratings drop comes as the show's only remaining original judge, Randy Jackson, prepares to leave the panel on Thursday's (16May13) finale.

This year's (13) panel has been tarnished by a series of bitter bust-ups between Carey and Minaj, with the pair arguing over their career success on several occasions.