Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2013

Accounting Policies [Abstract]

Basis of Accounting, Policy

The interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of ACGL and its wholly owned subsidiaries (together with ACGL, the “Company”). All significant intercompany transactions and balances have been eliminated in consolidation.

Use of Estimates, Policy

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates and assumptions. In the opinion of management, the accompanying unaudited interim consolidated financial statements reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of results on an interim basis. The results of any interim period are not necessarily indicative of the results for a full year or any future periods.