I turned in my resume to them at a career fair, and was contacted shortly after about setting up a group interview.
Interview one: two-on-one, at my university. Entirely behavioral with two senior managers. Was fairly easy but was still skeptical of being passed onto the next round.
Interview two: arranged for a day of interviews on the AB campus in St. Louis. Was me and 30 other potential interns, and we were split up dependent on which position we were going for (co-op, IT, marketing, &c.) This day of interviews consisted of a 5 on 5 student panel where we were also asked entirely behavioral questions. Was meant to be easygoing but was stressful nonetheless.
Took the recruiters one week to get back to me with an offer.