Mark Buthman graduated from the University of Iowa in May of 1982 with a degree in finance and business. The next month, he went to work for Kimberly-Clark as a cost analyst at a Memphis manufacturing facility.

Thirty-three years later, he is still with the paper-products maker, the only full-time employer he’s had. But not for much longer. Buthman, the company’s CFO since January 2003, will step down from that role on April 27 and retire at year-end.

Although he’s now one of the more senior finance chiefs among Fortune 500 companies, and his particular employer has $20 billion in annual revenue and 43,000 employees, Buthman says he never aspired to the role. For much of his career, he assumed he’d wind up running one of Kimberly-Clark’s businesses.

Mark Buthman

That changed in the late 1990s, when he was vice president of strategic planning and analysis and began to see that he was on a track that could take him to the top finance seat, if that was what he wanted. In 2000, Tom Falk, then the company’s chief operating officer, confided in Buthman that Falk would likely be Kimberly-Clark’s next chief executive, and that when that time came he wanted Buthman to be his CFO.

“Tom is probably the smartest person I’ve ever met, and he’s got a brilliant financial mind,” Buthman says of Falk, who’s still the CEO. “I told him, ‘Tom, you’re so good at finance that I’m not sure being your CFO would be much fun.’ I stepped back over a weekend to think and talk to my wife about it. I wanted to be at the leadership table that would set the company’s course for the future, so on Monday I told him that if that was the role he wanted me to play, I’d be honored to do it.”

Questioning his suitability for a role was old hat for Buthman. “Early on in my career, I was a beneficiary of leaders in our organization who always saw more potential in me than I saw in myself,” he says. “Before I became CFO, I never had a job at Kimberly-Clark that lasted more than two years. In each climb to the next level there was an element of uncertainty. Some people brim with confidence and make their own path. I learned along the way. People saw that potential in me, and that’s part of our job as leaders, to make that right judgment of when someone is ready to stretch to that next climb.”

A significant challenge arose six years into Buthman’s tenure as CFO. He had been 42 when he took on the role, leading a team whose senior members were largely in their 50s and 60s. “They were very good at what they did, they’d all been in their roles, at Kimberly-Clark or elsewhere, for at least 15 years, and they were not going to let me make a mistake,” he says. “They were like a warm blanket.”

In 2009, the company put an early retirement offer on the table, and eight of those people left in the same month. Suddenly, Buthman was missing 200 years of leadership experience. “We had robust succession plans for every one of them, and we had started to build capabilities behind them, but I didn’t think it was all going to happen at once,” he says. “I was really nervous.

It turned out to be an excellent learning experience, though. Buthman was overwhelmed by a surge of innovation and fresh ideas put forth by the new group over the next year.

For example, the new blood came up with a number of ideas for closing the books earlier, and since 2009 the turnaround time has shrunk from nine days to four. Forming a new leadership team with largely different backgrounds from the old one and reaping the benefits from the new perspectives opened his eyes. Buthman decided he would set their direction and “just let them go.”

“Now, we made more mistakes at first,” he says, “but it was a way to unlock our potential and make my impact much bigger. I was involved in important things that I really had to have my heart and soul in, but there are many important decisions that have to be made in a finance organization every day that are much better made by, for example, our treasurer, our head of tax, or the CFO of our consumer division, instead of having my hands in the mix.”

In fact, the need to make fewer decisions is a hallmark of a modern CFO, according to Buthman. When he started out back in the 1980s, he says, all information flowed uphill in an organization, so those at the top added value by making key strategic decisions.

“Today I actually make relatively few decisions, because information is now disseminated so widely. My job now is to set direction, set boundaries, help set culture, and try to put the people closest to a problem in [a] position to make good decisions.”

The idea that new leadership brings fresh ideas is actually one of the reasons behind Buthman’s plan to retire. “I am now one of those people who have been in a role for a long time,” he says. “The organization kind of adapts to you. Succession planning is not just about individual people, it’s about the whole ecosystem. Fresh eyes on old problems create innovation. I’m at a point where after 13 years in the CFO role, all my best ideas have been tried. I didn’t want to be the guy who stayed a year or two too long. I have a certain way of leading, and Maria Henry [who will take the finance reins from Buthman] will have a different way.”

He gives some other reasons for his impending departure. He’s accomplished most of what he set out to accomplish, for one. He also wants to “exercise [his] leadership muscles” outside of Kimberly-Clark, perhaps as a member of boards and as a mentor to young finance professionals. “I have an idea that new CFOs may not have enough support to get them jump-started, and there may be an opportunity to help them, either as a CFO or a coach,” he says.

Otherwise, Buthman, still young at 55, says he doesn’t yet know what else his future may hold. One thing he won’t do, he says, is take another CFO job.

Asked to name the highlight of his career, Buthman says that from a company standpoint there was no one event that stood out. He points instead to the three CEOs he’s worked under, each of which pushed Kimberly-Clark in a new direction.

The first, Darwin Smith in the 1980s, took it from a pulp-and-paper operation, managing millions of acres of timberland around the world, to a consumer-products company. The second, Wayne Sanders, pushed for a change in portfolio composition in the 1990s, when Buthman, as a point person on a series of acquisitions and divestitures, helped to again reshape the company. That effort created the international business that is now its growth driver. Falk’s tenure has been about shaping the organization’s execution focus, putting together a deeper leadership team, and improving its marketing, brand-building, and strategic-thinking capabilities.

From a personal standpoint, Buthman says, he’s proudest of having had an impact on people. Since he’s been at the company for such a long time, he’s gotten “hundreds” of notes since announcing his retirement plan. “Not one of them highlighted a business decision I made, or a compelling speech, or anything else business-oriented,” he says. “They were all about little ways I had an effect on them. You don’t think about that as you’re going through the journey, but to me the ability to inspire people is very fulfilling.”

How do you feel on the inside, Buthman is asked, about leaving the company after so many years? He doesn’t appear to be overly sentimental. “People come and go,” he says. “It doesn’t mean your personal relationships with them change. I’ve had a long run, so I’m anxious to try some other things to push myself and grow. I’m ready for a change.”