RLI Corp., an insurance holding company, underwrites property and casualty insurance in the United States and internationally. Its Casualty segment provides commercial and personal coverage products; and general liability products, such as coverage for third-party liability of commercial insureds, including manufacturers, contractors, apartments, and mercantile. This segment also offers coverages for security guards and in the areas of onshore energy-related businesses and environmental liability for underground storage tanks, contractors and asbestos, and environmental remediation specialists; and professional liability coverages focuses on providing errors and omission coverage to small to medium-sized design, technical, computer, and miscellaneous professionals. In addition, this segment provides commercial automobile liability and physical damage insurance to local, intermediate and long haul truckers, public transportation entities, and equipment dealers; incidental and related in