The producer of "American Idol" has filed for bankruptcy less than a month after the show's final episode aired.

Core Media Group filed for Chapter 11 bankruptcy protection on Thursday, saying it has not yet found a way to replace revenue earned from "American Idol."

Related: What the 'American Idol' finale looked like from the inside

The show was once a ratings juggernaut and huge profit driver for Fox. It averaged more than 20 million viewers every season from 2003, it's second year on the air, through 2011, according to ratings tracker Nielsen.

It reached a high point with an average of nearly 31 million viewers in 2006, and was the top rated show on television for eight consecutive seasons.

But its ratings fell hard afterward. By the end, it was no longer even Fox's top rated program, losing that distinction to the new drama Empire. The final episode, which aired in early April, drew around 13.3 million viewers.

Related: Why I'm going to miss 'American Idol'

Core's creditors include Sony Music Entertainment, Goldman Sachs and CBS Broadcasting.

Core also produced the hit series "So You Think You Can Dance," and managed the careers of multiple American Idol winners and finalists, according to its website.

- Chris Isidore contributed to this report