Don't sweat the small stuff. Don't get angry. Don't neglect your health.

Modern management wisdom was of little use to Larry H. Miller, who managed from the gut -- sweating every detail, busting phones in anger, and working long hours that threatened his health -- as he built a car-dealership empire and revived the Utah Jazz basketball team.

Miller, who died February 20 at 64 from complications of type 2 diabetes, relied on a photographic memory to muscle through an incredible workload.

A college dropout who learned the auto business as a parts manager, Miller bought his first dealership in 1979 and expanded to 39 dealerships across six states. He was most famous for owning the Jazz, a small-market team that improbably made it to the NBA finals twice during the 1990s.

Miller paid less than $25 million for the Jazz in the mid-1980s. It had steadily lost money. Forbes now values the franchise at $358 million. The Larry H. Miller Group owns a minor league baseball team, too, and a new, $100 million auto racing track. Overall, the Miller Group's 80 companies employ about 7,000 and have sales of more than $3 billion. Miller also donated land, buildings, everything -- including an entrepreneurship training center, at a cost of more than $50 million -- to build a suburban Sandy, Utah, campus for the Salt Lake Community College system.

After every Jazz home game, win or lose, Larry Miller sat down with the coaches and team executives for a postmortem. "We'd cover a lot of business," says Randy Rigby, president of the sports and entertainment parts of the Miller Group. "Some nights, we didn't leave until 12:30."

"He was famous for breaking phones. Intensity -- all day, every day," says Miller's son Greg, who is now CEO of Larry H. Miller Group. "He spent a lot of time at work as I was growing up. As a teenager, I resented that." And Dad didn't hand out praise, "no matter how hard I worked or how well I performed," Greg says.

But as Larry Miller's health failed last year, he took stock. He publicly voiced regrets about missing his kids' childhoods. "In his final months, he kind of let his guard down," Greg says. "He became the dad and the leader and the mentor that I wished he would've been. He was just a good guy. It was really enjoyable to work with him the last six months of his life."

Inheriting his father's inbox, Greg saw how a founder's attention to detail gets stretched when the company grows. A relatively small operation, for example, a 17-screen movie theater, was reporting directly to Larry that, finally, it had caught those kids who were buying arcade tokens and using them to ride Utah Transit Authority trains. "My dad was concerned with that level of detail," says Greg. "It became counterproductive."

But Greg also saw how his father's attention to detail was crucial to keeping up customer service at the dealerships. "He knew how to execute the basics better than anyone else," Greg says. "He did way more right than he did wrong."