Arch Capital Group Ltd. engages in the provision of property and casualty insurance and reinsurance lines. The insurance segment consists of the Company’s insurance underwriting units, which offer specialty product lines, including construction and national accounts; excess and surplus casualty; professional lines; programs; property, energy, marine and aviation; travel, accident and health; warranty and lender solutions, and others (consisting of alternative markets, excess workers' compensation and surety business). The reinsurance segment consists of its reinsurance underwriting units, which offer specialty product lines, including casualty; marine and aviation; other specialty; property catastrophe; property excluding property catastrophe, and others (consisting of life reinsurance and other). The mortgage segment includes its United States primary mortgage insurance business, investment and services related to United States credit-risk transfer.