James River Group Holdings Ltd owns and operates a group of specialty insurance and reinsurance companies. It reports business into four segments. The Excess and Surplus Lines segment, which is the key revenue driver, primarily offers commercial excess and surplus lines liability and excess property insurance products; the Specialty Admitted Insurance segment offers workers' compensation insurance coverage as well as specialty admitted fronting and program business; the Casualty Reinsurance segment offers commercial liability and non-catastrophe property reinsurance to US insurance companies and to the company's US-based insurance subsidiaries; and Corporate and Other segment.James River Group Holdings Ltd owns and operates a group of specialty insurance and reinsurance companies founded by members of its management team. It is organized for the purpose of acquiring & managing insurance and reinsurance entities.