Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2011
Related Party Transactions [Abstract]
Related Party Transactions	17. Related party transactions The ACE Foundation – Bermuda is an unconsolidated not-for-profit organization whose primary purpose is to fund charitable causes in Bermuda. The Trustees are principally ACE management. ACE maintains a non-interest bearing demand note receivable from the ACE Foundation – Bermuda, the balance of which was $29 million and $30 million, at December 31, 2011 and 2010, respectively. The receivable is included in Other assets in the consolidated balance sheets. The borrower has used the related proceeds to finance investments in Bermuda real estate, some of which have been rented to ACE employees at rates established by independent, professional real estate appraisers. The borrower uses income from the investments to both repay the note and to fund charitable activities. Accordingly, we report the demand note at the lower of its principal value or the fair value of assets held by the borrower to repay the loan, including the real estate properties.

The entire disclosure for related party transactions, including the nature of the relationship(s), a description of the transactions, the amount of the transactions, the effects of any change in the method of establishing the terms of the transaction from the previous period, stated interest rate, expiration date, terms and manner of settlement per the agreement with the related party, and amounts due to or from related parties. If the entity and one or more other entities are under common ownership or management control and this control affects the operating results or financial position, disclosure includes the nature of the control relationship even if there are no transactions between the entities. Disclosure may also include the aggregate amount of current and deferred tax expense for each statement of earnings presented where the entity is a member of a group that files a consolidated tax return, the amount of any tax related balances due to or from affiliates as of the date of each statement of financial position presented, the principal provisions of the method by which the consolidated amount of current and deferred tax expense is allocated to the members of the group and the nature and effect of any changes in that method. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

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