Arch Capital Group Ltd. writes insurance and reinsurance on worldwide basis. The Company operates in five segments: insurance, reinsurance, mortgage, other and corporate. The Company's insurance, reinsurance and mortgage segments are underwriting segments. The insurance segment's product lines include construction and national accounts; excess and surplus casualty; lenders products; professional lines; programs; property, energy, marine and aviation; travel, accident and health, and other, which includes alternative market risks and excess workers' compensation. The reinsurance segment's product lines include casualty; marine and aviation; other specialty; property catastrophe; property excluding property catastrophe, and other, which includes life reinsurance and casualty clash businesses. The mortgage segment includes the results of Arch Mortgage Insurance Company (Arch MI U.S.) and Arch Mortgage Insurance Designated Activity Company (Arch MI Europe).