It didn’t take a penny in federal bailout money. It grew throughout the financial crisis. It has consistently garnered top customer service rankings. And Fortune magazine just named it one of the 20 best companies to work for in America. Meet America’s good bank: USAA.

USAA is a San Antonio, Texas-based bank, insurance, and financial services company with 22,000 employees, serving 8 million current and former members of the military and their families. The company’s roots go back to 1922, when 25 army officers agreed to insure one another’s cars when no traditional companies would. Since then, USAA, or the United Services Automobile Association, has steadily grown.

By its very definition, USAA serves the middle class. It does business only with current and former members of the military and their families. Studies have shown that the U.S.’s all-volunteer military is dominated by members of the middle class, not the elite.

While other financial and insurance companies flirted with collapse, USAA’s net worth grew from $14.6 billion in 2008 to $19.3 billion in 2011. And it has continued lending money while other banks have tightened their loan operations despite billions in government funding to encourage liquidity. It has a free checking account, has been at the forefront of electronic banking, and reimburses up to $15 in other banks’ ATM fees. Its credit card rates are 43 percent lower than the national average.

The firm’s structure is one of its most interesting attributes. Unlike nearly every other Fortune 500 company, USAA is not a corporation.  It is an inter-insurance exchange made up of the people who have taken out policies with the firm. As a group, they are insured by each other and simultaneously own the company’s assets. Instead of paying stockholders, USAA distributes its profits to its members. In 2010, it distributed $1.3 billion.