Peter B. Lewis, the brash, iconoclastic and philanthropically generous chairman of Progressive Corp. died Saturday at his home in Coconut Grove, Fla.

Jennifer Frutchy, Lewis's philanthropic adviser, said Lewis died between 3 and 4 p.m., apparently of natural causes. He was 80.

During a career that lasted more than half a century, Lewis grew Mayfield-based Progressive Corp. from a tiny 100-person firm to the fourth-largest auto insurance company in the U.S., with $17 billion in premiums and 26,000 employees nationwide.

He was an important patron of architect Frank Gehry, whom he recommended to design the

at Case Western Reserve University.

Frank Gehry, left, and Peter Lewis at Case Western Reserve University in 1998, when CWRU unveiled Gehry's design for the university's Peter B. Lewis Building for the Weatherhead School of Management.

Lewis married his longtime partner, Janet Rosel, of Cleveland, in September, Frutchy said.

Glenn Renwick, whom Lewis identified in 1999 as his successor at Progressive, said Saturday night, "I'm devastated."

"He [Lewis] was a huge part of my life," Renwick said. "I don't think there are any words that can necessarily sum that up. Frankly, I got to follow in his footsteps, and they were big footsteps, and he encouraged me to do as well as I could."

Renwick said that Lewis spent the morning Saturday receiving a visit from his grandchildren, who were visiting before celebrating Thanksgiving.

"He had a really good day and was preparing to go out for the evening," Renwick said. "It was quite sudden and unexpected."

Gehry, speaking by phone Saturday night from Los Angeles, said that losing Lewis was like losing a brother.

"He was a risk-taker, he was open-minded, generous, quixotic, fun to be with - all of those things," Gehry said. "He was sort of an icon for the world, for my world anyway."

A funeral is being planned for Tuesday in Cleveland, but details are not yet settled, Frutchy said.

Lewis is survived by Rosel and by his brother, Daniel Lewis, of Coconut Grove; daughter Ivy Lewis, of Princeton, N.J.; sons Adam Joseph Lewis, of Aspen, Col. and Jonathan Lewis of Coconut Grove; his ex-wife, Toby Devan Lewis; and five grandchildren.

Lewis was one of the most successful business leaders in postwar Cleveland, with a personal fortune estimated at $1.6 billion in 2005 by Forbes magazine.

At the time of his death, Lewis' net worth hovered around $1 billion, Frutchy said. Over his lifetime, he donated roughly $500 million to various causes, she said.

Lewis built a significant art collection, bought homes in Aspen, Colorado and New York, and cruised the world's oceans aboard a 255-foot motor yacht. He named the boat "Lone Ranger" after the fictional TV hero he saw as a gun-slinging alter ego.

Peter Lewis traveled the seas in his "Lone Ranger," a renovated ocean-going salvage ship.

Lewis also used his money to promote causes ranging from the legalization of marijuana and the unsuccessful 2004 presidential candidacy of then Sen. John Kerry of Massachusetts, now the U.S. secretary of state.

Lewis supported the American Civil Liberties Union and helped launch Media Matters, the Center for American Progress, Third Way, Citizens for Ethics and Responsibility in Washington and other causes he viewed as progressive.

Lewis donated several million dollars to the recent successful marijuana legalization campaign in Washington state, making him the largest individual supporter of the effort, said lawyer Graham Boyd of Santa Cruz, Calif., Lewis's political strategist. Lewis also backed the Colorado legalization effort.

"The role that Peter has played in marijuana reform is that of leading this movement to the very brink of success," Boyd said Saturday night. "We've won two important states and I think just in the very near future there's going to be a cascade of victories that will be attributable to him and I do wish he had lived to see that success."

Lewis made no secret of his enjoyment of pot. Known for his flamboyant, freewheeling lifestyle, he was profiled in 1995 by Fortune magazine under the headline, "Sex, Reefer and Auto Insurance?"

Lewis played a key role in the career of Gehry, the world famous Los Angeles architect. By spending more than $5 million over a dozen years on plans for a house by Gehry that he decided not to build, Lewis bankrolled experiments with computer technology that enabled Gehry to design the widely acclaimed Guggenheim Museum in Bilbao, Spain.

Lewis donated $77 million to the Solomon R. Guggenheim Museum, the parent of the Bilbao branch, and served as chairman of the museum's board of trustees from 1998 to 2005, until highly public falling out with the museum's director, Thomas Krens, over the museum's financial management. Krens survived the confrontation and continued to expand the Guggenheim as a global franchise with branches around the world.

Lewis held honorary degrees from Case Western Reserve University and the Cleveland Institute of Art.

Despite having built his business in Cleveland, Lewis had a love-hate relationship with his hometown. He felt powerfully attached to Northeast Ohio and never forgot his closest childhood friends here.

Peter Lewis in 1954, the year before he graduated from Princeton University.

Yet he said he felt stung and "cut to my face" by snubs and slights he felt he suffered at the hands of the city's establishment during his rise in business, some of which he said were anti-Semitic in nature.

"I have felt marginalized, disdained, laughed at," Lewis said in an interview in 2002.

He once considered building a skyscraper headquarters and art museum on the Cleveland lakefront designed by Gehry with a dream team of famous contemporary artists, including Richard Serra and Claes Oldenburg.

Lewis was generous to Cleveland causes and donated $36.9 million to build the Gehry-designed Peter B. Lewis Building for the Weatherhead School of Management at Case Western Reserve University.

But when Lewis felt the building project was mismanaged, he lashed out, imposing a yearlong personal boycott against Cleveland philanthropies to protest what he saw as an incestuous old-boy network of interlocking board members on local charities, including CWRU.

Frank Gehry, left, and Peter Lewis attended the opening of the business school building at Case Western Reserve University named for Lewis that Gehry designed.

He resumed making local donations a year later, but was far more generous elsewhere, at one point donating $101 million to Princeton University for expanded arts programming, while letting it be known he was fundamentally disappointed with Cleveland.

"Cleveland is not high on my list because it's all palaver," Lewis said in 2006 after making his gift to Princeton.

But Lewis never gave up his condominium in Beachwood and continued to visit the city to hear proposals from those seeking his largesse and to keep on eye on Progressive, where he remained chairman until his death.

Those who knew Lewis said he'd never sever ties with Cleveland, no matter how rocky the relationship became.

"I think he'll die a Clevelander," former U.S. Sen. Robert Kerrey, a friend of Lewis, said in 2002. "You may not get as much of his money as you'd like, but you won't lose him."

Kerrey's words proved prophetic.

In 2012, Lewis

, his biggest philanthropic gift in his hometown in a decade. After he ended his boycott in 2003,

he made locals gifts only up to $1 million until the art institute donation.

Lewis said in an interview in Beachwood in July, 2012, that he made the donation to recognize that the $150-million-plus Uptown development in University Circle, of which the art institute is part, has met the high hopes he articulated for the project in 2004.

"It's the first time in a long time I've been impressed by Cleveland," he said. "I'm impressed by the achievement and accomplishment, I'm impressed all around."

In May, Lewis publicly buried the hatchet with CWRU. Speaking at the university's commencement, Lewis urged thousands of freshly minted graduates "love and support Case Western Reserve University" and to "cherish your alma mater."

In his personal and professional life, Lewis believed in being searingly honest. In the late 1990s and early 2000s, amid corporate accounting scandals that toppled CEOs including Ken Lay of Enron, Lewis was proud that Progressive issued monthly financial statements. It was a way, he said, to emphasize that Progressive was committed to complete transparency in reporting financial information.

Lewis made no secret of his ambition to make Progressive the best company in the world, a desire so deeply rooted he event related it to his own virility.

At one company gathering, he said he planned to keep working until the "Rockefeller event," a reference to reports of Nelson Rockefeller dying in the arms of a 25-year-old lover.

Lewis's own success confirmed his conviction that his unconventional style and iconoclastic methods made fundamental good sense. It also confirmed his belief that Cleveland would be better off if the city had more entrepreneurs than lawyers in positions of power.

"Lawyers are functionaries hired by the people who do something," he said, "but we've got a situation where they're running the town. It's absurd. Those aren't the people who drive creativity. Their whole job is to keep people from doing things."

Born on Nov. 11, 1933, Lewis grew up as the oldest of four children in a middle class Jewish family in Cleveland Heights. He started working part time at age 12 for Progressive, the small auto insurance company co-founded by his father, Joseph Lewis, and business partner, Jack Green.

Earning good grades, Lewis gained admission to Princeton University, where he excelled. But Lewis' family life was shattered during his sophomore year when his younger brother, Jonathan, was killed in a car accident. Two years later, Lewis' father was diagnosed with a malignant brain tumor and told he had two weeks to live.

After graduating from Princeton in 1955, Lewis started working at Progressive as an accountant, though without the assurances his father had given him that he would rise in the firm.

In 1965, Lewis and his mother, Helen Lewis, borrowed $2.5 million to undertake a leveraged buyout of the company, then called Progressive Mutual Insurance Co., pledging their majority stake as collateral.

Progressive at the time had 100 employees and $19.3 million in written premiums.

From that point, Lewis positioned the company for rapid growth by focusing on insuring high risk drivers, by creating an innovative pricing system with free quotes on competitors' rates, and by offering instant claims service.

Lewis met his future wife, Toby Devan, while he was at Princeton. They married soon after he graduated and raised three children: Jonathan, Ivy and Adam Joseph.

The Lewises divorced in 1981 after peter decided he no longer wanted to be monogamous. But he and Toby remained close after parting. In 1985, Lewis hired Toby to manage the Progressive art collection, which became a cornerstone of the company's corporate identity and one of the largest and most admired collections of its kind in the nation, with more than 6,000 objects.

Toby Lewis at Progressive Corp. in 2002, when she headed the company's corporate art program.

As a corporate leader, Lewis viewed contemporary art as a model of creativity he felt he could apply to business. He was proud that hanging Andy Warhol's "Mao" portraits angered some Progressive employees. His goal was to shock them out of complacency and to make them view the world through fresh eyes - something he felt artists do every day.

Through Lewis' involvement with the Museum of Contemporary Art Cleveland, then the Cleveland Center for Contemporary Art, Lewis met Gehry at a lecture in 1985 and immediately asked him to design a house for him in Lyndhurst. Over the next decade, the design evolved through more than a dozen iterations, attracting the attention of architecture critics including Paul Goldberger, who wrote a lengthy article about it in The New York Times magazine.

Lewis finally cancelled the project in the late 1990s after the budget had reached $80 million. But Gehry said the $5 million in fees Lewis paid for the unbuilt project enabled the him to achieve a career breakthrough in Bilbao and in other world-famous buildings.

"He kept me trying things, exploring things," Gehry said Saturday of Lewis and the house project. "I think he never intended to build the house. He didn't need it. He didn't live like a rich guy, except for the boat and his plane, but that was later."

In 1998, Lewis had to have his left leg amputated below the knee after a congenital vascular problem led to an infection that would not heal. He later stepped down as Progressive president and CEO while retaining the office of chairman.

Two years later, Lewis' widely known affection for marijuana landed him in trouble with new Zealand authorities. After taking a commercial flight from the U.S. to watch the America's Cup races from aboard his yacht, Lewis was arrested at Auckland airport after drug-sniffing dogs helped police find pot in his briefcase.

After spending a night in jail, Lewis was released after admitting guilt and donating money to a local charity.

He later called the event "a crisis in my life," in which he said he learned, "I have the capacity to be stupid and arrogant."

Even so, Lewis never tired of funding campaigns to legalize marijuana, and joined billionaires George Soros and John Sperling in supporting a series of state initiatives to replace mandatory sentences with treatment for some nonviolent drug offenders.

Lewis was reviled by conservative commentators including Fox Network's Bill O'Reilly. But Lewis considered himself a libertarian first and foremost. He wanted drugs legalized and regulated, like alcohol.

"As long as you're not hurting somebody else, who the hell cares?" Lewis said. "Kill yourself. God bless you."

Princeton, with $220 million in gifts, remained the biggest beneficiary of a generosity that made Lewis the biggest individual donor in the university's history, according to Progressive.

His gifts included $60 million for a Gehry-designed science library and an endowment for the Lewis-Sigler Genomics Institute.

But his biggest Princeton donation,

the $101 million gift in 2006, focused on a cause that for Lewis became an abiding passion, second only to his love of insurance - the arts.

Renwick, Progressive's president and CEO, said that Lewis remained closely involved in the company's business in recent years.

"Peter was by far the best chair-leader Progressive could ever have," he said. "He was very involved with the board. We spoke every Sunday."

During those conversations, Renwick, 58, said his relationship with Lewis bloomed into a friendship, and a mentorship.

"He was more than happy [with Progressive in recent years] and, if I'm being less than humble, he was proud to see how things had moved on from what he had started."

Renwick said that Lewis was especially pleased with the Progressive advertising campaign built around "Flo," a ditzy-smart redhead who dresses somewhat like a nurse and who plays the part of a cashier in a bright white setting meant to evoke a Progressive superstore.

"Peter loved Flo," Renwick said, because the campaign built around the character helped Progressive build its brand nationally.

"The fact that it's a household name, made him sit back and think, 'that's what I always envisioned,' " Renwick said.