The United Services Automobile Association has a funny legal structure: it's not a corporation and has no shareholders. Policyholders and account holders are paid any profits. In that respect, it functions very much like a credit union; technically, it's structured as
a Texas-based and Texas Department of Insurance regulated unincorporated reciprocal inter-insurance exchange and Fortune 500 financial services company offering banking, investing, and insurance to people and families that serve, or served, in the United States military.
Normally a company like this is a corporation so that its owners can benefit from limited liability: otherwise, if the company loses millions or billions, any one of the individual owners / members could be held liable for paying those millions and billions! However, the Texas laws which govern them as a Texas-based inter-insurance exchange also serve to limit the liability of members.
The banking services are provided by the USAA Federal Savings Bank, which is structured as a (drumroll) federal savings bank. They also own a couple of other random businesses.