I talked to their recruiters at a career fair at my school. They called me shortly after the career fair was over and invited me to a dinner with other potential recruits at a steak house the following evening. Prior to the dinner, I was also invited to the first interview.
The dinner was mostly informational (it was not an interview), though the person who eventually interviewed me was there. They mainly told us about the company, the interview process, and what to expect.
They recommend "business professional dress" for the interview, so have a suit and tie ahead of time, because the process moves pretty quickly at the beginning (they fly their recruiters in for the job fairs and want to get bang for their buck).
For the interview, it was an hour long with three behavioral questions (If you find a list of a few dozen behavioral questions online, they will probably be on there), three analytical questions (come up with something innovative given a certain scenario, design something that does something, etc).
After that, it was about two weeks before I was invited to a second interview. They fly you out to San Antonio, put you up in a nice hotel. There's a dinner the night before where you get to meet with some managers from the company. The next morning (early) they shuttle you from the hotel to the USAA Campus, serve breakfast, and then the interviews begin.
The second interview is almost identical to the first one, the only real difference is there are two people in the interview instead of one, and the questions are the same format, but different.
After that, they serve lunch, have various people come and speak about the company, internship program, etc, and give a tour of the campus (it is huge).
I was extended an offer about three weeks later.