SALT LAKE CITY -- Congressman Jason Chaffetz stunned Utah's political scene with an announcement he will not seek re-election in 2018.

"You know what? I just turned 50. I'm sleeping on a cot in my office. I spent more than 1,500 nights away from my family and it was time to recalibrate," he told reporters on Wednesday.

Chaffetz insisted there were no "ulterior motives" for his desire to step away from congress, but a desire to be with his family and return to private sector.

"It's good to go out on top," he told FOX 13.

His decision surprised many.

"It was unexpected. I didn't see it coming," said Utah GOP Chairman James Evans.

"I was as stunned as anyone to learn of Congressman Chaffetz’s decision not to seek re-election or any public office in 2018," Utah Governor Gary Herbert said in a statement. "Congressman Chaffetz has represented Utah in the United States House of Representatives with distinction, and I have appreciated working with him over the last eight years on issues vital to our state. His razor sharp mind, expansive knowledge and gift for communicating will serve him well when he transitions into the private sector."

National Republican Congressional Committee Chairman Steve Stivers wished Chaffetz well, and predicted Utah's 3rd Congressional District would remain in GOP hands.

"Republicans have a deep bench of talented candidates in Utah who are more than up to this challenge. The NRCC is very confident in our ability to keep this seat red in November 2018," he said in a prepared statement.

Democrats called his retirement "long overdue."

"Chairman Chaffetz’ behavior has long been beneath the dignity of the office he holds and he should step down as Chairman of the Oversight Committee immediately. Clearly, Chaffetz crumbled under the weight of the widespread backlash that he’s been facing for refusing to do his job, which is a victory for all Americans and will serve as a motivating force for the grassroots," the Democratic Congressional Campaign Committee said in a statement.

It's likely not the last anyone has heard of Chaffetz. He would not dismiss a run for Utah governor in 2020, when asked about it by FOX 13.

"I'm going to keep every door open," he said.

Sen. Orrin Hatch, who faced a potential challenger in Chaffetz, told reporters on Wednesday he understood why the congressman was stepping away.

"I think he's kind of tired of being back there all the time, I understand that syndrome, and he's done a very good job, I have a real high regard for him, and I wish him well whatever he decides to do," Hatch said.

Utah's senior senator reiterated that he was running for re-election.

"Well right now my intention is to run again, but you never know, it's two years away, all I can say is no I don't think anybody's gunning for me, let me put it that way," Hatch said.

Chaffetz said Wednesday he was most proud of the investigations he led as House Oversight Committee Chairman into Benghazi and Hillary Clinton's email scandal. It was those investigations that made him a flash point of controversy.

He recently faced angry crowds at a town hall meeting who demanded he investigate President Donald Trump.

"I kind of thrive on being in the heat of the moment, people yelling, screaming and throwing things," Chaffetz told FOX 13. "That's probably part of it I will miss. It may be hard for some people to believe, but the reality is I just happen to love my family and serving in congress -- it's a privilege, but it's hard."

Chaffetz didn't say exactly what he has lined up post-congress. Asked if he was offered a rumored gig at FOX News Channel, he replied: "None of that can come to fruition until you actually go forward and make this announcement. Then you can pursue what those opportunities may be."

Now that Utah's 3rd Congressional District is an open field, Evans said he expected a number of names to come forward to replace him. On Wednesday, a large number of names had already started to circulate.

RELATED: Who wants to run for Chaffetz's seat? Some names being floated

Chaffetz's Democratic challenger, Dr. Kathie Allen, told FOX 13 she wasn't sure if his decision made her campaign easier or tougher.

"I'm having a good day today," she quipped.

Allen said she planned to campaign next week in southeastern Utah.

"Nothing has changed for me, the reason I’m running to bring integrity back to government," she said. "Nothing has changed in my platform and my motivation."

With one more year left in office, Chaffetz said he wanted to focus on pushing President Trump to rescind the Bears Ears National Monument.

"Something I'd like to do sooner rather than later," he said.

Watch Chaffetz speak with FOX 13 here: