FORTUNE magazine released its 2012 list of "100 Best Companies to Work For," which contained four insurers and a handful of vendors and consultants that play in the insurance space. The top-rated carrier on this year’s list is USAA, which provides a full range of financial services to member of the U.S. military and their families. The insurer, ranked at number 20 (down from 17 last year) has a 7-percent job growth and 23,211 U.S. employees.