Other than State Farm, are there any other large companies that are mutual companies?
Mutual is a term used in the insurance industry to describe how a company is organized. A mutual has no stockholder other than its policy holders.
Many (most?) large insurance companies are mutuals
Metropolitan, Pruduntial, New York Life, and Northwestern Mutual jump to mind.
Sometimes, they “demutualize.” Back in 2000, MetLife did so. Each policy holder was issued shares of stock in the demutualized company.