That didn’t take long.

“American Idol,” the genre-shattering singing competition show that went off the air just a year ago because of falling ratings, is coming back to television on ABC.

The network said today on “Good Morning America” that it would revive the former Fox hit sometime during the 2017-18 television season.

ABC did not name a host or say who the judges would be. Ryan Seacrest, the longtime host of “American Idol,” joined ABC and Disney’s syndicated morning show, “Live,” last week.

The revival of “American Idol” is a head-spinning move, even by the standards of broadcast networks desperately searching for a hit. But these are tough times in broadcast television — in the last three years, ratings among adults under 50 have declined 24 percent.

“American Idol,” which debuted in 2002, was a once dominant ratings player for Fox, and the standard-bearer for a wave of amateur talent shows that followed it. But over its last few seasons — as it cycled through judges, and as rival shows like “The Voice” slowed its momentum — the show’s audience collapsed. Fox announced it was ending the “American Idol” run two years ago, and the final episode was in April 2016. Few were surprised when the decision was announced.

But in the time since, as ratings have plunged, the big four networks have turned to reboots in the hopes of regaining viewers. Fox, in particular, has brought back old properties like “24,” “Lethal Weapon” and “Prison Break” to fill the “American Idol” gap.

Fox is hardly alone in the revival mania. “Will and Grace” returns to NBC in the fall; “Roseanne” is probably coming back on the air with ABC at some point in the next television season; and CBS made versions of “Training Day” and “MacGyver” this past season. Even “Love Connection” is being revived, with Andy Cohen serving as host on a Fox reboot.

But those shows — or the movie revivals — had been dormant for years. Though series like “Nashville” and “The Mindy Project” were canceled by network TV and found new life elsewhere (on CMT and Hulu), it is exceedingly rare for a network show to return this quickly on a rival network.

ABC made the decision to bring back “American Idol” just a week before its annual upfront presentation, a meticulously devised showcase for advertisers on which a network announces its fall lineup.

“‘American Idol’ is a pop-culture staple that left the air too soon,” said Channing Dungey, president of ABC Entertainment. “ABC is the right home to reignite the fan base.”

Until a few weeks ago, NBC was also in negotiations for “American Idol.” But ABC ultimately won the rights from the show’s producers, FremantleMedia North America and 19 Entertainment, which is part of the CORE Media Group.

At its height, “American Idol” was one of the most dominant shows in television. It was a ratings force that sometimes drew more than 30 million viewers a night — the sort of viewership that only playoff football games get these days. It was also a juggernaut for the music industry and a path to career success for aspiring singers — to be minted on “American Idol,” like Carrie Underwood, was a path to becoming a star.

Those days have long passed.

Still, “American Idol” averaged more than 11 million viewers in its final season, a respectable showing, and was one of the top-rated shows among adults under 50, according to Nielsen’s delayed viewing data. Whether those numbers are sustainable, or if more people were tuning in because “American Idol” was in its final season, will soon be determined.

It was only a year ago that Simon Cowell, now a host on “America’s Got Talent,” suggested that his failed “American Idol” follow-up act, “The X-Factor,” could have survived the current TV climate if given more time and if judged by the standard of just how far TV ratings have fallen.

“We treated it as a failure,” Cowell said. “I wasn’t aware the market had gone down to that level so quickly. I was in this La-La Land head space of 30 or 40 million, and I thought 12 million feels terrible.”

© 2017 The New York Times Company