Interior Secretary Ryan Zinke will step down from his post at the end of the year, President Donald Trump announced Saturday. Bloomberg News first reported the development.

What are the details?

Around 9 a.m. Saturday, Bloomberg reporter Jennifer Jacobs reported that Zinke had notified the president that he intends to step down at year's end. Just minutes later, Trump confirmed Zinke's departure via Twitter, thanking Zinke for his service and announcing that Zinke's successor would be named next week.

Secretary of the Interior @RyanZinke will be leaving the Administration at the end of the year after having served for a period of almost two years. Ryan has accomplished much during his tenure and I want to thank him for his service to our Nation.......
— Donald J. Trump (@realDonaldTrump) December 15, 2018

.......The Trump Administration will be announcing the new Secretary of the Interior next week.
— Donald J. Trump (@realDonaldTrump) December 15, 2018

According to Jacobs, "concern about legal costs and scrutiny of his travel, political activity and potential conflicts of interest were factors in Zinke's decision."

Bloomberg News explains:

Zinke's decision, expected to be announced on Wednesday, comes as Democrats, who've vowed to grill the him over his conduct, are about to take control of the House of Representatives, raising the prospect of heightened oversight -- and a crush of legal bills from defending himself. Concern about all the scrutiny and legal costs on the horizon were factors in Zinke's decision to quit, said the people, who asked not to be identified to discuss it.

Trump has reportedly been aware of Zinke's intentions for several days, allowing the White House to get a jump on naming his replacement.

Prior to accepting his position as secretary of the Interior Department, Zinke represented Montana in the House of Representatives.

Who might replace Zinke?

Jacobs reported:

BREAKING: Trump has been notified Zinke plans to step down and has begun searching for replacement.

Names that have emerged include Nevada's Dean Heller, Nevada's Adam Laxalt, Wisconsin's Scott Walker, Idaho's Butch Otter, Utah's Sean Reyes and others.
— Jennifer Jacobs (@JenniferJJacobs) December 15, 2018