With the Thursday morning close of Paramount Global and Skydance Media’s troubled $8.4 billion merger comes a new set of challenges: actually running the thing. The company’s new CEO, David Ellison, acknowledged the merger’s bumpy road in an open letter addressed to the company’s employees, shareholders and customers on Thursday.

David Ellison, the new CEO of Paramount, referred to what he called a “challenging period” for CBS News, while praising the division’s “long tradition of impactful reporting,” including the legacy of 60 Minutes.

Skydance Media and Paramount Global have completed their merger, creating a new media conglomerate and ending months of turmoil over the deal that has drawn allegations of corruption directed at the Trump administration.

The new chief executive of Paramount repeatedly said on Thursday he doesn’t want to “politicize” the company as its merger with Skydance Media finally closes, two weeks after the Federal Communications Commission approved the $8.