American Idol is coming back... but not on Fox. The singing competition helped put Fox on the map and reshape reality television when it came to the United States in 2002, but after eroding ratings and increasing production costs, Fox and American Idol parted ways in 2016.

You all know the story: ABC scooped up an American Idol revival earlier this year and will debut its version of the series in 2018, causing plenty of drama between the networks. Naturally, the question of American Idol's departure came up at the Fox executive panel at the Television Critics Association summer press tour on Tuesday, and Fox CEO and chairman Dana Walden chose her words carefully but didn't hold back.

"The economics were terrible for us, at that moment," Walden said, on Fox's decision to not renew the one-time ratings juggernaut as its numbers dropped over 70 percent during its tenure at Fox.

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Fremantle Media, which owns the Idol franchise, didn't want to change the format much, Walden says, and that became another stumbling block between the two. She recalled Fremantle was open to minor cosmetic fixes, but wasn't keen on risking or disrupting the chemistry of the show with bigger format changes.

Walden said, "[Fremantle] liked the show the way it was, they were willing to make small tweaks. What we got back from them was, 'We would prefer to end this run than to do anything that dramatically changes the format.' We looked at [America's Got Talent] and when they brought in Howard Stern and shook up the chemistry and involved someone who had a different promotional platform that could feed into their primary audience on the show, and Fremantle really — and again I don't blame them — they felt like the format worked and they wanted to protect it."

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That left Fox in a dilemma, which was to move forward "at that extraordinary loss" or stop running the show for some time and heavily promote one final season.

"Then the question was would you ever like to have American Idol back? Yes," Walden said. "Did we want it back a year or two later? No. We felt like that was very fraudulent to our viewers."

Walden admitted that Fox was "a little bit back on our heels" so the network wasn't as aggressive as it could have been in getting the show back, and another network was.

Well, at least Fox has The Four, right?

American Idol returns on ABC in 2018.