I remember him on the Johnny Carson show, how the hell did he get so rich?
He got into the television production side of things in the early 90's. First he had an interview show, then a stand up comedy show, showcasing young comedians. They weren't very good, but they were safe and didn't rock the boat, so they got syndicated a lot to stations that needed filler for the very late night slots (2am - 4am).
From there, he threw money into safe documentary and lifestyle shows that had high syndication value. He also bought into a few digital stations, so he reaps a lot of cash from those.
Smart guy.