8. Operating Segment Information We conduct our worldwide reinsurance business through three operating segments: Property and Marine, Casualty and Finite Risk. The Property and Marine operating segment includes principally property and marine reinsurance coverages that are written in the United States and international markets. This operating segment includes property reinsurance, crop reinsurance and marine and aviation reinsurance. The Property and Marine operating segment includes reinsurance contracts that are either catastrophe excess-of-loss, per-risk excess-of-loss or proportional contracts. The Casualty operating segment includes reinsurance contracts that cover general and product liability, professional liability, accident and health, umbrella liability, workers' compensation, casualty clash, automobile liability, surety, trade credit, and political risk. We generally seek to write casualty reinsurance on an excess-of-loss basis. We write first dollar proportional casualty reinsurance contracts on an opportunistic basis. The Finite Risk operating segment includes principally structured reinsurance contracts with ceding companies whose needs may not be met efficiently through traditional reinsurance products. In exchange for contractual features that limit our downside risk, reinsurance contracts that we classify as finite risk provide the potential for significant profit commission to the ceding company. The classes of risks underwritten through finite risk contracts are generally consistent with the classes covered by traditional products. The finite risk contracts that we underwrite generally provide prospective protection, meaning coverage is provided for losses that are incurred after inception of the contract, as contrasted with retrospective coverage, which covers losses that are incurred prior to inception of the contract. The three main categories of finite risk contracts are quota share, multi-year excess-of-loss and whole account aggregate stop loss. In managing our operating segments, we use