From Wikipedia:
USAA was founded in 1922 by a group of U.S. Army officers to self-insure one another when they were unable to secure auto insurance because of the perception that they, as military officers, were a high-risk group.
From their site's front page: USAA means United Services Automobile Association and its insurance, banking, investment and other companies. Banks Member FDIC. https://www.usaa.com
Notice the FDIC. Credit unions are not insured via FDIC, they use NCUA. http://www.gobankingrates.com/banking/fdic-versus-ncua-insur...