Summary Of Significant Accounting Policies (Policy)	12 Months Ended
Dec. 31, 2011
Summary Of Significant Accounting Policies [Abstract]
Basis Of Presentation	a) Basis of presentation ACE Limited is a holding company incorporated in Zurich, Switzerland. ACE Limited, through its various subsidiaries, provides a broad range of insurance and reinsurance products to insureds worldwide. ACE operates through the following business segments: Insurance – North American, Insurance – Overseas General, Global Reinsurance, and Life. Refer to Note 15 for additional information. The accompanying consolidated financial statements, which include the accounts of ACE Limited and its subsidiaries (collectively, ACE, we, us, or our), have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and, in the opinion of management, reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of the results and financial position for such periods. All significant intercompany accounts and transactions have been eliminated. 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, 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. Amounts included in the consolidated financial statements reflect our best estimates and assumptions; actual amounts could differ materially from these estimates. ACE's principal estimates include: • unpaid loss and loss expense reserves and future policy benefits reserves; • the valuation of value of business acquired (VOBA) and amortization of deferred policy acquisition costs and VOBA; • reinsurance recoverable, including a provision for uncollectible reinsurance; • the assessment of risk transfer for certain structured insurance and reinsurance contracts; • the valuation of the investment portfolio and assessment of OTTI; • the valuation of deferred tax assets; • the valuation of derivative instruments related to guaranteed living benefits (GLB); and • the valuation of goodwill.
Premiums	b) Premiums Premiums are generally recognized as written upon inception of the policy. For multi-year policies for which premiums written are payable in annual installments, only the current annual premium is included as written at policy inception due to the ability of the insured/reinsured to commute or cancel coverage within the term of the policy. The remaining annual premiums are included as written at each successive anniversary date within the multi-year term. For property and casualty (P&C) insurance and reinsurance products, premiums written are primarily earned on a pro-rata basis over the terms of the policies to which they relate. Unearned premiums represent the portion of premiums written applicable to the unexpired portion of the policies in force. For retrospectively-rated policies, written premiums are adjusted to reflect expected ultimate premiums consistent with changes to reported losses, or other measures of exposure as stated in the policy, and earned over the coverage period of the policy. For retrospectively-rated multi-year policies, the amount of premiums recognized in the current period is computed, using a with-and-without method, as the difference between the ceding enterprise's total contract costs before and after the experience under the contract at the reporting date. Accordingly, for retrospectively-rated multi-year policies, additional premiums are generally written and earned when losses are incurred. Mandatory reinstatement premiums assessed on reinsurance policies are earned in the period of the loss event that gave rise to the reinstatement premiums. All remaining unearned premiums are recognized over the remaining coverage period. Premiums from long duration contracts such as certain traditional term life, whole life, endowment, and long duration personal accident and health (A&H) policies are generally recognized as revenue when due from policyholders. Traditional life policies include those contracts with fixed and guaranteed premiums and benefits. Benefits and expenses are matched with such income to result in the recognition of profit over the life of the contracts. Retroactive loss portfolio transfer (LPT) contracts in which the insured loss events occurred prior to the inception of the contract are evaluated to determine whether they meet the established criteria for reinsurance accounting. If reinsurance accounting is appropriate, written premiums are fully earned and corresponding losses and loss expenses recognized at the inception of the contract. The contracts can cause significant variances in gross premiums written, net premiums written, net premiums earned, and net incurred losses in the years in which they are written. Reinsurance contracts sold not meeting the established criteria for reinsurance accounting are recorded using the deposit method as described below in Note 1 k). Reinsurance premiums assumed are based on information provided by ceding companies supplemented by our own estimates of premium when we have not received ceding company reports. The information used in establishing these estimates is reviewed and adjustments are recorded in the period in which they are determined. These premiums are earned over the coverage terms of the related reinsurance contracts and range from one to three years.
Deferred Policy Acquisition Costs And Value Of Business Acquired	c) Deferred policy acquisition costs and value of business acquired Policy acquisition costs consist of commissions, premium taxes, and underwriting and other costs that vary with, and are primarily related to, the production of premium. A VOBA intangible asset is established upon the acquisition of blocks of long duration contracts and represents the present value of estimated net cash flows for the contracts in force at the time of the acquisition. Acquisition costs and VOBA, collectively policy acquisition costs, are deferred and amortized. Policy acquisition costs on P&C contracts are generally amortized ratably over the period in which premiums are earned. Policy acquisition costs on long duration contracts are amortized over the estimated life of the contracts, generally in proportion to premium revenue recognized. Policy acquisition costs are reviewed to determine if they are recoverable from future income, including investment income. Unrecoverable costs are expensed in the period identified. Advertising costs are expensed as incurred except for direct-response campaigns, principally related to A&H business produced by the Insurance – Overseas General segment, which are deferred and recognized over the expected future benefit period. For individual direct-response marketing campaigns that we can demonstrate have specifically resulted in incremental sales to customers and such sales have probable future economic benefits, incremental costs directly related to the marketing campaigns are capitalized. Deferred marketing costs are reviewed regularly for recoverability and amortized over five years, the expected economic future benefit period. The expected future benefit period is evaluated periodically based on historical results and adjusted prospectively. The amount of deferred marketing costs reported in Deferred policy acquisition costs was $236 million and $253 million at December 31, 2011 and 2010, respectively. The amortization expense for deferred marketing costs was $128 million, $115 million, and $103 million for the years ended December 31, 2011, 2010, and 2009, respectively.
Reinsurance	d) Reinsurance ACE assumes and cedes reinsurance with other insurance companies to provide greater diversification of business and minimize the net loss potential arising from large risks. Ceded reinsurance contracts do not relieve ACE of its primary obligation to its policyholders. For both ceded and assumed reinsurance, risk transfer requirements must be met in order to obtain reinsurance status for accounting purposes, principally resulting in the recognition of cash flows under the contract as premiums and losses. To meet risk transfer requirements, a reinsurance contract must include insurance risk, consisting of both underwriting and timing risk, and a reasonable possibility of a significant loss for the assuming entity. To assess risk transfer for certain contracts, ACE generally develops expected discounted cash flow analyses at contract inception. Deposit accounting is used for contracts that do not meet risk transfer requirements. Deposit accounting requires that consideration received or paid be recorded in the balance sheet as opposed to recording premiums written or losses incurred in the statement of operations. Non-refundable fees on deposit contracts are earned based on the terms of the contract. Refer to Note 1 k). Reinsurance recoverable includes the balances due from reinsurance companies for paid and unpaid losses and loss expenses and policy benefits that will be recovered from reinsurers, based on contracts in force. The method for determining the reinsurance recoverable on unpaid losses and loss expenses incurred but not reported (IBNR) involves actuarial estimates consistent with those used to establish the associated liability for unpaid losses and loss expenses as well as a determination of ACE's ability to cede unpaid losses and loss expenses. Reinsurance recoverable is presented net of a provision for uncollectible reinsurance determined based upon a review of the financial condition of reinsurers and other factors. The provision for uncollectible reinsurance is based on an estimate of the amount of the reinsurance recoverable balance that will ultimately be unrecoverable due to reinsurer insolvency, a contractual dispute, or any other reason. The valuation of this provision includes several judgments including certain aspects of the allocation of reinsurance recoverable on IBNR claims by reinsurer and a default analysis to estimate uncollectible reinsurance. The primary components of the default analysis are reinsurance recoverable balances by reinsurer, net of collateral, and default factors used to determine the portion of a reinsurer's balance deemed uncollectible. The definition of collateral for this purpose requires some judgment and is generally limited to assets held in an ACE-only beneficiary trust, letters of credit, and liabilities held with the same legal entity for which ACE believes there is a contractual right of offset. The determination of the default factor is principally based on the financial strength rating of the reinsurer. Default factors require considerable judgment and are determined using the current financial strength rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions. The more significant considerations include, but are not necessarily limited to, the following: • For reinsurers that maintain a financial strength rating from a major rating agency, and for which recoverable balances are considered representative of the larger population (i.e., default probabilities are consistent with similarly rated reinsurers and payment durations conform to averages), the financial rating is based on a published source and the default factor is based on published default statistics of a major rating agency applicable to the reinsurer's particular rating class. When a recoverable is expected to be paid in a brief period of time by a highly rated reinsurer, such as certain property catastrophe claims, a default factor may not be applied; • For balances recoverable from reinsurers that are both unrated by a major rating agency and for which management is unable to determine a credible rating equivalent based on a parent, affiliate, or peer company, we determine a rating equivalent based on an analysis of the reinsurer that considers an assessment of the creditworthiness of the particular entity, industry benchmarks, or other factors as considered appropriate. We then apply the applicable default factor for that rating class. For balances recoverable from unrated reinsurers for which the ceded reserve is below a certain threshold, we generally apply a default factor of 25 percent, consistent with published statistics of a major rating agency; • For balances recoverable from reinsurers that are either insolvent or under regulatory supervision, we establish a default factor and resulting provision for uncollectible reinsurance based on reinsurer-specific facts and circumstances. Upon initial notification of an insolvency, we generally recognize an expense for a substantial portion of all balances outstanding, net of collateral, through a combination of write-offs of recoverable balances and increases to the provision for uncollectible reinsurance. When regulatory action is taken on a reinsurer, we generally recognize a default factor by estimating an expected recovery on all balances outstanding, net of collateral. When sufficient credible information becomes available, we adjust the provision for uncollectible reinsurance by establishing a default factor pursuant to information received; and • For other recoverables, management determines the provision for uncollectible reinsurance based on the specific facts and circumstances. The methods used to determine the reinsurance recoverable balance and related provision for uncollectible reinsurance are regularly reviewed and updated and any resulting adjustments are reflected in earnings in the period identified. Prepaid reinsurance premiums represent the portion of premiums ceded to reinsurers applicable to the unexpired coverage terms of the reinsurance contracts in force. The value of reinsurance business assumed of $35 million and $92 million at December 31, 2011 and 2010, respectively, included in Other assets in the accompanying consolidated balance sheets, represents the excess of estimated ultimate value of the liabilities assumed under retroactive reinsurance contracts over consideration received. The value of reinsurance business assumed is amortized and recorded to losses and loss expenses based on the payment pattern of the losses assumed and ranges between 7 and 40 years. The unamortized value is reviewed regularly to determine if it is recoverable based upon the terms of the contract, estimated losses and loss expenses, and anticipated investment income. Unrecoverable amounts are expensed in the period identified.
Investments	e) Investments Fixed maturity investments are classified as either available for sale or held to maturity. The available for sale portfolio is reported at fair value. The held to maturity portfolio includes securities for which we have the ability and intent to hold to maturity or redemption and is reported at amortized cost. Equity securities are classified as available for sale and are recorded at fair value. Short-term investments comprise securities due to mature within one year of the date of purchase and are recorded at fair value which typically approximates cost. Short-term investments include certain cash and cash equivalents, which are part of investment portfolios under the management of external investment managers. Other investments principally comprise life insurance policies, policy loans, trading securities, other direct equity investments, investment funds, and limited partnerships. • Life insurance policies are carried at policy cash surrender value. • Policy loans are carried at outstanding balance. • Trading securities are recorded on a trade date basis and carried at fair value. Unrealized gains and losses on trading securities are reflected in net income. • Other investments over which ACE can exercise significant influence are accounted for using the equity method. • All other investments over which ACE cannot exercise significant influence are carried at fair value with changes in fair value recognized through OCI. For these investments, investment income and realized gains are recognized as related distributions are received. • Partially-owned investment companies comprise entities in which we hold an ownership interest in excess of three percent. These investments as well as ACE's investments in investment funds where its ownership interest is in excess of three percent are accounted for under the equity method because ACE exerts significant influence. These investments apply investment company accounting to determine operating results, and ACE retains the investment company accounting in applying the equity method. This means that investment income, realized gains or losses, and unrealized gains or losses are included in the portion of equity earnings reflected in Other (income) expense. Investments in partially-owned insurance companies primarily represent direct investments in which ACE has significant influence and, as such, meet the requirements for equity accounting. We report our share of the net income or loss of the partially-owned insurance companies in Other (income) expense. Investments in partially-owned insurance companies over which ACE does not exert significant influence are carried at fair value. Realized gains or losses on sales of investments are determined on a first-in, first-out basis. Unrealized appreciation (depreciation) on investments is included as a separate component of AOCI in shareholders' equity. We regularly review our investments for OTTI. Refer to Note 3 for additional information. With respect to securities where the decline in value is determined to be temporary and the security's value is not written down, a subsequent decision may be made to sell that security and realize a loss. Subsequent decisions on security sales are the result of changing or unforeseen facts and circumstances (i.e., arising from a large insured loss such as a catastrophe), deterioration of the creditworthiness of the issuer or its industry, or changes in regulatory requirements. We believe that subsequent decisions to sell such securities are consistent with the classification of the majority of the portfolio as available for sale. We use derivative instruments including futures, options, swaps, and foreign currency forward contracts for the purpose of managing certain investment portfolio risks and exposures. Refer to Note 10 for additional information. Derivatives are reported at fair value and recorded in the accompanying consolidated balance sheets in Accounts payable, accrued expenses, and other liabilities with changes in fair value included in Net realized gains (losses) in the consolidated statements of operations. Collateral held by brokers equal to a percentage of the total value of open futures contracts is included in the investment portfolio. Net investment income includes interest and dividend income and amortization of fixed maturity market premiums and discounts and is net of investment management and custody fees. For mortgage-backed securities, and any other holdings for which there is a prepayment risk, prepayment assumptions are evaluated and revised as necessary. Any adjustments required due to the resultant change in effective yields and maturities are recognized prospectively. Prepayment fees or call premiums that are only payable when a security is called prior to its maturity are earned when received and reflected in Net investment income. ACE participates in a securities lending program operated by a third party banking institution whereby certain assets are loaned to qualified borrowers and from which it earns an incremental return. Borrowers provide collateral, in the form of either cash or approved securities, of 102 percent of the fair value of the loaned securities. Each security loan is deemed to be an overnight transaction. Cash collateral is invested in a collateral pool which is managed by the banking institution. The collateral pool is subject to written investment guidelines with key objectives which include the safeguard of principal and adequate liquidity to meet anticipated redemptions. The fair value of the loaned securities is monitored on a daily basis, with additional collateral obtained or refunded as the fair value of the loaned securities changes. The collateral is held by the third party banking institution, and the collateral can only be accessed in the event that the institution borrowing the securities is in default under the lending agreement. As a result of these restrictions, we consider our securities lending activities to be non-cash investing and financing activities. An indemnification agreement with the lending agent protects us in the event a borrower becomes insolvent or fails to return any of the securities on loan. The fair value of the securities on loan is included in fixed maturities and equity securities. The securities lending collateral is reported as a separate line in total assets with a related liability reflecting our obligation to return the collateral plus interest. Similar to securities lending arrangements, securities sold under reverse repurchase agreements, whereby ACE sells securities and repurchases them at a future date for a predetermined price, are accounted for as collateralized investments and borrowings and are recorded at the contractual repurchase amounts plus accrued interest. Assets to be repurchased are the same, or substantially the same, as the assets transferred and the transferor, through right of substitution, maintains the right and ability to redeem the collateral on short notice. The fair value of the underlying securities is included in fixed maturities and equity securities. In contrast to securities lending programs, the use of cash received is not restricted. We report the obligation to return the cash as Short-term debt in the consolidated balance sheets. Refer to Note 4 for a discussion on the determination of fair value for ACE's various investment securities.
Cash	f) Cash Cash includes cash on hand and deposits with an original maturity of three months or less at time of purchase. Cash held by external money managers is included in Short-term investments. We have agreements with a third party bank provider which implemented two international multi-currency notional cash pooling programs. In each program, participating ACE entities establish deposit accounts in different currencies with the bank provider and each day the credit or debit balances in every account are notionally translated into a single currency (U.S. dollars) and then notionally pooled. The bank extends overdraft credit to any participating ACE entity as needed, provided that the overall notionally-pooled balance of all accounts in each pool at the end of each day is at least zero. Actual cash balances are not physically converted and are not commingled between legal entities. Any overdraft balances incurred under this program by an ACE entity would be guaranteed by ACE Limited (up to $350 million in the aggregate). Our revolving credit facility allows for same day drawings to fund a net pool overdraft should participating ACE entities withdraw contributed funds from the pool.
Goodwill And Other Intangible Assets	g) Goodwill and other intangible assets Goodwill represents the excess of the cost of acquisitions over the fair value of net assets acquired and is not amortized. Goodwill is assigned at acquisition to the applicable reporting unit of the acquired entities giving rise to the goodwill. Goodwill impairment tests are performed annually, or more frequently if circumstances indicate a possible impairment. For goodwill impairment testing, we use a qualitative assessment to determine whether it is more likely than not (i.e., more than a 50 percent probability) that the fair value of a reporting unit is greater than its carrying amount. If our assessment indicates less than a 50 percent probability that fair value exceeds carrying value, we quantitatively estimate a reporting unit's fair value using a consistently applied combination of the following models: an earnings multiple, a book value multiple, a discounted cash flow, or an allocated market capitalization model. The earnings and book value models apply multiples of comparable publicly traded companies to forecasted earnings or book value of each reporting unit and consider current market transactions. The discounted cash flow model applies a discount to estimated cash flows including a terminal value calculation. The market capitalization model allocates market capitalization to each reporting unit. Where appropriate, we consider the impact of a control premium. Goodwill recorded in connection with investments in partially-owned insurance companies is recorded in Investments in partially-owned insurance companies and is also measured for impairment annually. Indefinite lived intangible assets are not subject to amortization. Finite lived intangible assets are amortized over their useful lives, generally ranging from 4 to 20 years. The carrying amounts of intangible assets are regularly reviewed for indicators of impairment. Impairment is recognized if the carrying amount is not recoverable from its undiscounted cash flows and is measured as the difference between the carrying amount and fair value.
Unpaid Losses And Loss Expenses	h) Unpaid losses and loss expenses A liability is established for the estimated unpaid losses and loss expenses under the terms of, and with respect to, ACE's policies and agreements. These amounts include provision for both reported claims (case reserves) and IBNR claims. The methods of determining such estimates and establishing the resulting liability are reviewed regularly and any adjustments are reflected in operations in the period in which they become known. Future developments may result in losses and loss expenses materially greater or less than recorded amounts. Except for net loss and loss expense reserves of $59 million net of discount held at December 31, 2011, representing structured settlements for which the timing and amount of future claim payments are reliably determinable, ACE does not discount its P&C loss reserves. Structured settlements represent contracts purchased from life insurance companies primarily to settle workers' compensation claims, where payments to the claimant by the life insurance company are expected to be made in the form of an annuity. ACE retains the liability to the claimant in the event that the life insurance company fails to pay. At December 31, 2011, the gross liability for the amount due to claimants was $644 million and reinsurance recoverables for amounts due from the life insurance companies was $585 million. For structured settlement contracts where payments are guaranteed regardless of claimant life expectancy, the amounts recoverable from the life insurance companies are included in Other assets, as they do not meet the requirements for reinsurance accounting. At December 31, 2011, there was $59 million included in Other assets in the consolidated balance sheets relating to structured settlements. Included in unpaid losses and loss expenses are liabilities for asbestos and environmental (A&E) claims and expenses. These unpaid losses and loss expenses are principally related to claims arising from remediation costs associated with hazardous waste sites and bodily-injury claims related to asbestos products and environmental hazards. The estimation of these liabilities is particularly sensitive to changes in the legal environment, including specific settlements that may be used as precedents to settle future claims. However, ACE does not anticipate future changes in laws and regulations in setting its A&E reserve levels. Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves first reported in previous calendar years and excludes the effect of losses from the development of earned premiums from previous accident years. With respect to crop business, prior to the December 2010 acquisition of Rain and Hail Insurance Service, Inc. (Rain and Hail), reports relating to the previous crop year(s) were normally received in subsequent calendar years and this typically resulted in adjustments to the previously reported premiums, losses and loss expenses, and profit share commission. Following the acquisition, such information is available before the close of the calendar year. Commencing with the quarter ended September 30, 2009, prior period development for the crop business includes adjustments to both crop losses and loss expenses and the related crop profit share commission. For purposes of analysis and disclosure, management views prior period development to be changes in the nominal value of loss estimates from period to period and excludes changes in loss estimates that do not arise from the emergence of claims, such as those related to uncollectible reinsurance, interest, unallocated loss adjustment expenses, or foreign currency. Accordingly, specific items excluded from prior period development include the following: gains/losses related to foreign currency remeasurement; losses recognized from the early termination or commutation of reinsurance agreements that principally relate to the time value of money; changes in the value of reinsurance business assumed reflected in losses incurred but principally related to the time value of money; and losses that arise from changes in estimates of earned premiums from prior accident years. Except for foreign currency remeasurement, which is disclosed separately, these items are included in current year losses.
Future Policy Benefits	i) Future policy benefits The valuation of long duration contract reserves requires management to make estimates and assumptions regarding expenses, mortality, persistency, and investment yields. Such estimates are primarily based on historical experience and information provided by ceding companies and include a margin for adverse deviation. Interest rates used in calculating reserves range from less than one percent to six percent and one percent to seven percent at December 31, 2011 and 2010, respectively. Actual results could differ materially from these estimates. Management monitors actual experience, and where circumstances warrant, will revise assumptions and the related reserve estimates. Revisions are recorded in the period they are determined. Certain of our long duration contracts have assets that do not qualify for separate account reporting under GAAP (failed separate accounts). The assets related to failed separate accounts are reported in Other investments and the offsetting liabilities are reported in Future policy benefits in the consolidated balance sheets. Changes in the fair value of failed separate account assets are reported in Other income (expense) and the offsetting movements in the failed separate account liabilities are included in Policy benefits in the consolidated statements of operations.
Assumed Reinsurance Programs Involving Minimum Benefit Guarantees Under Annuity Contracts	j) Assumed reinsurance programs involving minimum benefit guarantees under annuity contracts ACE reinsures various death and living benefit guarantees associated with variable annuities issued primarily in the United States and Japan. Each reinsurance treaty covers variable annuities written during a limited period, typically not exceeding two years. We generally receive a monthly premium during the accumulation phase of the covered annuities (in-force) based on a percentage of either the underlying accumulated account values or the underlying accumulated guaranteed values. Depending on an annuitant's age, the accumulation phase can last many years. To limit our exposure under these programs, all reinsurance treaties include aggregate claim limits and many include an aggregate deductible. The guarantees which are payable on death, referred to as guaranteed minimum death benefits (GMDB), principally cover shortfalls between accumulated account value at the time of an annuitant's death and either i) an annuitant's total deposits; ii) an annuitant's total deposits plus a minimum annual return; or iii) the highest accumulated account value attained at any policy anniversary date. In addition, a death benefit may be based on a formula specified in the variable annuity contract that uses a percentage of the growth of the underlying contract value. Liabilities for GMDBs are based on cumulative assessments or premiums to date multiplied by a benefit ratio that is determined by estimating the present value of benefit payments and related adjustment expenses divided by the present value of cumulative assessment or expected fees during the contract period. Under reinsurance programs covering GLBs, we assume the risk of guaranteed minimum income benefits (GMIB) and guaranteed minimum accumulation benefits (GMAB) associated with variable annuity contracts. The GMIB risk is triggered if, at the time the contract holder elects to convert the accumulated account value to a periodic payment stream (annuitize), the accumulated account value is not sufficient to provide a guaranteed minimum level of monthly income. The GMAB risk is triggered if, at contract maturity, the contract holder's account value is less than a guaranteed minimum value. Our GLB reinsurance product meets the definition of a derivative for accounting purposes and is carried at fair value with changes in fair value recognized in income and classified as described below. As the assuming entity, we are obligated to provide coverage until the earlier of the expiration of the underlying guaranteed benefit or the treaty expiration date. Premiums received under the reinsurance treaties are classified as premium. Expected losses allocated to premiums received are classified as policy benefits and valued similar to GMDB reinsurance. Other changes in fair value, principally arising from changes in expected losses allocated to expected future premiums, are classified as Net realized gains (losses). Fair value represents management's estimate of exit price and thus includes a risk margin. We may recognize a realized loss for other changes in fair value due to adverse changes in the capital markets (i.e., declining interest rates and/or declining equity markets) and changes in policyholder behavior (i.e., increased annuitization or decreased lapse rates) although we expect the business to be profitable. We believe this presentation provides the most meaningful disclosure of changes in the underlying risk within the GLB reinsurance programs for a given reporting period. Refer to Note 5 c) for additional information.
Deposit Assets And Liabilities	k) Deposit assets and liabilities Deposit assets arise from ceded reinsurance contracts purchased that do not transfer significant underwriting or timing risk. Under deposit accounting, consideration received or paid, excluding non-refundable fees, is recorded as a deposit asset or liability in the balance sheet as opposed to recording ceded premiums and losses in the statement of operations. Interest income on deposits, representing the consideration received or to be received in excess of cash payments related to the deposit contract, is earned based on an effective yield calculation. The calculation of the effective yield is based on the amount and timing of actual cash flows at the balance sheet date and the estimated amount and timing of future cash flows. The effective yield is recalculated periodically to reflect revised estimates of cash flows. When a change in the actual or estimated cash flows occurs, the resulting change to the carrying amount of the deposit asset is reported as income or expense. Deposit assets of $133 million and $144 million at December 31, 2011 and 2010, respectively, are reflected in Other assets in the consolidated balance sheets and the accretion of deposit assets related to interest pursuant to the effective yield calculation is reflected in Net investment income in the consolidated statements of operations. Non-refundable fees are earned based on contract terms. Non-refundable fees paid but unearned are reflected in Other assets in the consolidated balance sheets and earned fees are reflected in Other (income) expense in the consolidated statements of operations. Deposit liabilities include reinsurance deposit liabilities of $318 million and $351 million and contract holder deposit funds of $345 million and $70 million at December 31, 2011 and 2010, respectively. The reinsurance deposit liabilities arise from contracts sold for which there is not a significant transfer of risk. At contract inception, the deposit liability equals net cash received. An accretion rate is established based on actuarial estimates whereby the deposit liability is increased to the estimated amount payable over the contract term. The deposit accretion rate is the rate of return required to fund expected future payment obligations. We periodically reassess the estimated ultimate liability and related expected rate of return. Changes to the amount of the deposit liability are reflected through Interest expense to reflect the cumulative effect of the period the contract has been in force, and by an adjustment to the future accretion rate of the liability over the remaining estimated contract term. Contract holder deposit funds represent a liability for investment contracts sold that do not meet the definition of an insurance contract and are sold with a guaranteed rate of return. The liability equals accumulated policy account values, which consist of the deposit payments plus credited interest, less withdrawals and amounts assessed through the end of the period.
Foreign Currency Remeasurement And Translation	l) Foreign currency remeasurement and translation The functional currency for each of our foreign operations is generally the currency of the local operating environment. Transactions in currencies other than a foreign operation's functional currency are remeasured into the functional currency and the resulting foreign exchange gains and losses are reflected in Net realized gains (losses) in the consolidated statements of operations. Functional currency assets and liabilities are translated into the reporting currency, U.S. dollars, using period end rates of exchange and the related translation adjustments are recorded as a separate component of AOCI. Functional statement of operations amounts expressed in functional currencies are translated using average exchange rates. Gains and losses resulting from foreign currency transactions are recorded in Net realized gains (losses) in the consolidated statements of operations.
Administrative Expenses	m) Administrative expenses Administrative expenses generally include all operating costs other than policy acquisition costs. The Insurance – North American segment manages and uses an in-house third-party claims administrator, ESIS Inc. (ESIS). ESIS performs claims management and risk control services for domestic and international organizations that self-insure P&C exposures as well as internal P&C exposures. The net operating results of ESIS are included within Administrative expenses in the consolidated statements of operations and were $21 million, $85 million, and $26 million for the years ended December 31, 2011, 2010, and 2009, respectively.
Income Taxes	n) Income taxes Income taxes have been recorded related to those operations subject to income taxes. Deferred tax assets and liabilities result from temporary differences between the amounts recorded in the consolidated financial statements and the tax basis of our assets and liabilities. Refer to Note 8 for additional information. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance against deferred tax assets is recorded if it is more likely than not that all, or some portion, of the benefits related to deferred tax assets will not be realized. The valuation allowance assessment considers tax planning strategies, where applicable. We recognize uncertain tax positions deemed more likely than not of being sustained upon examination. Recognized income tax positions are measured at the largest amount that is greater than 50 percent likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
Earnings Per Share	o) Earnings per share Basic earnings per share is calculated using the weighted-average shares outstanding including participating securities with non-forfeitable rights to dividends such as unvested restricted stock. All potentially dilutive securities including stock options are excluded from the basic earnings per share calculation. In calculating diluted earnings per share, the weighted-average shares outstanding is increased to include all potentially dilutive securities. Basic and diluted earnings per share are calculated by dividing net income available to common shareholders by the applicable weighted-average number of shares outstanding during the year.
Cash Flow Information	p) Cash flow information Premiums received and losses paid associated with the GLB reinsurance products, which as discussed previously meet the definition of a derivative instrument for accounting purposes, are included within cash flows from operating activities in the consolidated statement of cash flows. Cash flows, such as settlements and collateral requirements, associated with all other derivative instruments are included on a net basis within cash flows from investing activities in the consolidated statement of cash flows. Purchases, sales, and maturities of short-term investments are recorded net for purposes of the consolidated statements of cash flows and are classified with cash flows related to fixed maturities.
Derivatives	q) Derivatives ACE recognizes all derivatives at fair value in the consolidated balance sheets and participates in derivative instruments in two principal ways: (i) To sell protection to customers as an insurance or reinsurance contract that meets the definition of a derivative for accounting purposes. For 2011 and 2010, the reinsurance of GLBs was our primary product falling into this category; and (ii) To mitigate financial risks, principally arising from investment holdings, products sold, or assets and liabilities held in foreign currencies. For these instruments, changes in assets or liabilities measured at fair value are recorded as realized gains or losses in the consolidated statement of operations. We did not designate any derivatives as accounting hedges during 2011, 2010, or 2009.
Share-Based Compensation	r) Share-based compensation ACE measures and records compensation cost for all share-based payment awards at grant-date fair value. Compensation costs are recognized for share-based payment awards with only service conditions that have graded vesting schedules on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards. Refer to Note 12 for additional information.

Summary Of Significant Accounting Policies (Policy)

12 Months Ended

Dec. 31, 2011

Summary Of Significant Accounting Policies [Abstract]

a) Basis of presentation

ACE Limited is a holding company incorporated in Zurich, Switzerland. ACE Limited, through its various subsidiaries, provides a broad range of insurance and reinsurance products to insureds worldwide. ACE operates through the following business segments: Insurance – North American, Insurance – Overseas General, Global Reinsurance, and Life. Refer to Note 15 for additional information.

The accompanying consolidated financial statements, which include the accounts of ACE Limited and its subsidiaries (collectively, ACE, we, us, or our), have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and, in the opinion of management, reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of the results and financial position for such periods. All significant intercompany accounts and transactions have been eliminated.

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, 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. Amounts included in the consolidated financial statements reflect our best estimates and assumptions; actual amounts could differ materially from these estimates. ACE's principal estimates include:

• unpaid loss and loss expense reserves and future policy benefits reserves;

• the valuation of value of business acquired (VOBA) and amortization of deferred policy acquisition costs and VOBA;

• reinsurance recoverable, including a provision for uncollectible reinsurance;

• the assessment of risk transfer for certain structured insurance and reinsurance contracts;

• the valuation of the investment portfolio and assessment of OTTI;

• the valuation of deferred tax assets;

• the valuation of derivative instruments related to guaranteed living benefits (GLB); and

• the valuation of goodwill.

Premiums

b) Premiums

Premiums are generally recognized as written upon inception of the policy. For multi-year policies for which premiums written are payable in annual installments, only the current annual premium is included as written at policy inception due to the ability of the insured/reinsured to commute or cancel coverage within the term of the policy. The remaining annual premiums are included as written at each successive anniversary date within the multi-year term.

For property and casualty (P&C) insurance and reinsurance products, premiums written are primarily earned on a pro-rata basis over the terms of the policies to which they relate. Unearned premiums represent the portion of premiums written applicable to the unexpired portion of the policies in force. For retrospectively-rated policies, written premiums are adjusted to reflect expected ultimate premiums consistent with changes to reported losses, or other measures of exposure as stated in the policy, and earned over the coverage period of the policy. For retrospectively-rated multi-year policies, the amount of premiums recognized in the current period is computed, using a with-and-without method, as the difference between the ceding enterprise's total contract costs before and after the experience under the contract at the reporting date. Accordingly, for retrospectively-rated multi-year policies, additional premiums are generally written and earned when losses are incurred.

Mandatory reinstatement premiums assessed on reinsurance policies are earned in the period of the loss event that gave rise to the reinstatement premiums. All remaining unearned premiums are recognized over the remaining coverage period.

Premiums from long duration contracts such as certain traditional term life, whole life, endowment, and long duration personal accident and health (A&H) policies are generally recognized as revenue when due from policyholders. Traditional life policies include those contracts with fixed and guaranteed premiums and benefits. Benefits and expenses are matched with such income to result in the recognition of profit over the life of the contracts.

Retroactive loss portfolio transfer (LPT) contracts in which the insured loss events occurred prior to the inception of the contract are evaluated to determine whether they meet the established criteria for reinsurance accounting. If reinsurance accounting is appropriate, written premiums are fully earned and corresponding losses and loss expenses recognized at the inception of the contract. The contracts can cause significant variances in gross premiums written, net premiums written, net premiums earned, and net incurred losses in the years in which they are written. Reinsurance contracts sold not meeting the established criteria for reinsurance accounting are recorded using the deposit method as described below in Note 1 k).

Reinsurance premiums assumed are based on information provided by ceding companies supplemented by our own estimates of premium when we have not received ceding company reports. The information used in establishing these estimates is reviewed and adjustments are recorded in the period in which they are determined. These premiums are earned over the coverage terms of the related reinsurance contracts and range from one to three years.

Deferred Policy Acquisition Costs And Value Of Business Acquired

c) Deferred policy acquisition costs and value of business acquired

Policy acquisition costs consist of commissions, premium taxes, and underwriting and other costs that vary with, and are primarily related to, the production of premium. A VOBA intangible asset is established upon the acquisition of blocks of long duration contracts and represents the present value of estimated net cash flows for the contracts in force at the time of the acquisition. Acquisition costs and VOBA, collectively policy acquisition costs, are deferred and amortized. Policy acquisition costs on P&C contracts are generally amortized ratably over the period in which premiums are earned. Policy acquisition costs on long duration contracts are amortized over the estimated life of the contracts, generally in proportion to premium revenue recognized. Policy acquisition costs are reviewed to determine if they are recoverable from future income, including investment income. Unrecoverable costs are expensed in the period identified.

Advertising costs are expensed as incurred except for direct-response campaigns, principally related to A&H business produced by the Insurance – Overseas General segment, which are deferred and recognized over the expected future benefit period. For individual direct-response marketing campaigns that we can demonstrate have specifically resulted in incremental sales to customers and such sales have probable future economic benefits, incremental costs directly related to the marketing campaigns are capitalized. Deferred marketing costs are reviewed regularly for recoverability and amortized over five years, the expected economic future benefit period. The expected future benefit period is evaluated periodically based on historical results and adjusted prospectively. The amount of deferred marketing costs reported in Deferred policy acquisition costs was $236 million and $253 million at December 31, 2011 and 2010, respectively. The amortization expense for deferred marketing costs was $128 million, $115 million, and $103 million for the years ended December 31, 2011, 2010, and 2009, respectively.

Reinsurance

d) Reinsurance

ACE assumes and cedes reinsurance with other insurance companies to provide greater diversification of business and minimize the net loss potential arising from large risks. Ceded reinsurance contracts do not relieve ACE of its primary obligation to its policyholders.

For both ceded and assumed reinsurance, risk transfer requirements must be met in order to obtain reinsurance status for accounting purposes, principally resulting in the recognition of cash flows under the contract as premiums and losses. To meet risk transfer requirements, a reinsurance contract must include insurance risk, consisting of both underwriting and timing risk, and a reasonable possibility of a significant loss for the assuming entity. To assess risk transfer for certain contracts, ACE generally develops expected discounted cash flow analyses at contract inception. Deposit accounting is used for contracts that do not meet risk transfer requirements. Deposit accounting requires that consideration received or paid be recorded in the balance sheet as opposed to recording premiums written or losses incurred in the statement of operations. Non-refundable fees on deposit contracts are earned based on the terms of the contract. Refer to Note 1 k).

Reinsurance recoverable includes the balances due from reinsurance companies for paid and unpaid losses and loss expenses and policy benefits that will be recovered from reinsurers, based on contracts in force. The method for determining the reinsurance recoverable on unpaid losses and loss expenses incurred but not reported (IBNR) involves actuarial estimates consistent with those used to establish the associated liability for unpaid losses and loss expenses as well as a determination of ACE's ability to cede unpaid losses and loss expenses.

Reinsurance recoverable is presented net of a provision for uncollectible reinsurance determined based upon a review of the financial condition of reinsurers and other factors. The provision for uncollectible reinsurance is based on an estimate of the amount of the reinsurance recoverable balance that will ultimately be unrecoverable due to reinsurer insolvency, a contractual dispute, or any other reason. The valuation of this provision includes several judgments including certain aspects of the allocation of reinsurance recoverable on IBNR claims by reinsurer and a default analysis to estimate uncollectible reinsurance. The primary components of the default analysis are reinsurance recoverable balances by reinsurer, net of collateral, and default factors used to determine the portion of a reinsurer's balance deemed uncollectible. The definition of collateral for this purpose requires some judgment and is generally limited to assets held in an ACE-only beneficiary trust, letters of credit, and liabilities held with the same legal entity for which ACE believes there is a contractual right of offset. The determination of the default factor is principally based on the financial strength rating of the reinsurer. Default factors require considerable judgment and are determined using the current financial strength rating, or rating equivalent, of each reinsurer as well as other key considerations and assumptions. The more significant considerations include, but are not necessarily limited to, the following:

• For reinsurers that maintain a financial strength rating from a major rating agency, and for which recoverable balances are considered representative of the larger population (i.e., default probabilities are consistent with similarly rated reinsurers and payment durations conform to averages), the financial rating is based on a published source and the default factor is based on published default statistics of a major rating agency applicable to the reinsurer's particular rating class. When a recoverable is expected to be paid in a brief period of time by a highly rated reinsurer, such as certain property catastrophe claims, a default factor may not be applied;

• For balances recoverable from reinsurers that are both unrated by a major rating agency and for which management is unable to determine a credible rating equivalent based on a parent, affiliate, or peer company, we determine a rating equivalent based on an analysis of the reinsurer that considers an assessment of the creditworthiness of the particular entity, industry benchmarks, or other factors as considered appropriate. We then apply the applicable default factor for that rating class. For balances recoverable from unrated reinsurers for which the ceded reserve is below a certain threshold, we generally apply a default factor of 25 percent, consistent with published statistics of a major rating agency;

• For balances recoverable from reinsurers that are either insolvent or under regulatory supervision, we establish a default factor and resulting provision for uncollectible reinsurance based on reinsurer-specific facts and circumstances. Upon initial notification of an insolvency, we generally recognize an expense for a substantial portion of all balances outstanding, net of collateral, through a combination of write-offs of recoverable balances and increases to the provision for uncollectible reinsurance. When regulatory action is taken on a reinsurer, we generally recognize a default factor by estimating an expected recovery on all balances outstanding, net of collateral. When sufficient credible information becomes available, we adjust the provision for uncollectible reinsurance by establishing a default factor pursuant to information received; and

• For other recoverables, management determines the provision for uncollectible reinsurance based on the specific facts and circumstances.

The methods used to determine the reinsurance recoverable balance and related provision for uncollectible reinsurance are regularly reviewed and updated and any resulting adjustments are reflected in earnings in the period identified.

Prepaid reinsurance premiums represent the portion of premiums ceded to reinsurers applicable to the unexpired coverage terms of the reinsurance contracts in force.

The value of reinsurance business assumed of $35 million and $92 million at December 31, 2011 and 2010, respectively, included in Other assets in the accompanying consolidated balance sheets, represents the excess of estimated ultimate value of the liabilities assumed under retroactive reinsurance contracts over consideration received. The value of reinsurance business assumed is amortized and recorded to losses and loss expenses based on the payment pattern of the losses assumed and ranges between 7 and 40 years. The unamortized value is reviewed regularly to determine if it is recoverable based upon the terms of the contract, estimated losses and loss expenses, and anticipated investment income. Unrecoverable amounts are expensed in the period identified.

Investments

e) Investments

Fixed maturity investments are classified as either available for sale or held to maturity. The available for sale portfolio is reported at fair value. The held to maturity portfolio includes securities for which we have the ability and intent to hold to maturity or redemption and is reported at amortized cost. Equity securities are classified as available for sale and are recorded at fair value. Short-term investments comprise securities due to mature within one year of the date of purchase and are recorded at fair value which typically approximates cost. Short-term investments include certain cash and cash equivalents, which are part of investment portfolios under the management of external investment managers.

Other investments principally comprise life insurance policies, policy loans, trading securities, other direct equity investments, investment funds, and limited partnerships.

• Life insurance policies are carried at policy cash surrender value.

• Policy loans are carried at outstanding balance.

• Trading securities are recorded on a trade date basis and carried at fair value. Unrealized gains and losses on trading securities are reflected in net income.

• Other investments over which ACE can exercise significant influence are accounted for using the equity method.

• All other investments over which ACE cannot exercise significant influence are carried at fair value with changes in fair value recognized through OCI. For these investments, investment income and realized gains are recognized as related distributions are received.

• Partially-owned investment companies comprise entities in which we hold an ownership interest in excess of three percent. These investments as well as ACE's investments in investment funds where its ownership interest is in excess of three percent are accounted for under the equity method because ACE exerts significant influence. These investments apply investment company accounting to determine operating results, and ACE retains the investment company accounting in applying the equity method. This means that investment income, realized gains or losses, and unrealized gains or losses are included in the portion of equity earnings reflected in Other (income) expense.

Investments in partially-owned insurance companies primarily represent direct investments in which ACE has significant influence and, as such, meet the requirements for equity accounting. We report our share of the net income or loss of the partially-owned insurance companies in Other (income) expense. Investments in partially-owned insurance companies over which ACE does not exert significant influence are carried at fair value.

Realized gains or losses on sales of investments are determined on a first-in, first-out basis. Unrealized appreciation (depreciation) on investments is included as a separate component of AOCI in shareholders' equity. We regularly review our investments for OTTI. Refer to Note 3 for additional information.

With respect to securities where the decline in value is determined to be temporary and the security's value is not written down, a subsequent decision may be made to sell that security and realize a loss. Subsequent decisions on security sales are the result of changing or unforeseen facts and circumstances (i.e., arising from a large insured loss such as a catastrophe), deterioration of the creditworthiness of the issuer or its industry, or changes in regulatory requirements. We believe that subsequent decisions to sell such securities are consistent with the classification of the majority of the portfolio as available for sale.

We use derivative instruments including futures, options, swaps, and foreign currency forward contracts for the purpose of managing certain investment portfolio risks and exposures. Refer to Note 10 for additional information. Derivatives are reported at fair value and recorded in the accompanying consolidated balance sheets in Accounts payable, accrued expenses, and other liabilities with changes in fair value included in Net realized gains (losses) in the consolidated statements of operations. Collateral held by brokers equal to a percentage of the total value of open futures contracts is included in the investment portfolio.

Net investment income includes interest and dividend income and amortization of fixed maturity market premiums and discounts and is net of investment management and custody fees. For mortgage-backed securities, and any other holdings for which there is a prepayment risk, prepayment assumptions are evaluated and revised as necessary. Any adjustments required due to the resultant change in effective yields and maturities are recognized prospectively. Prepayment fees or call premiums that are only payable when a security is called prior to its maturity are earned when received and reflected in Net investment income.

ACE participates in a securities lending program operated by a third party banking institution whereby certain assets are loaned to qualified borrowers and from which it earns an incremental return. Borrowers provide collateral, in the form of either cash or approved securities, of 102 percent of the fair value of the loaned securities. Each security loan is deemed to be an overnight transaction. Cash collateral is invested in a collateral pool which is managed by the banking institution. The collateral pool is subject to written investment guidelines with key objectives which include the safeguard of principal and adequate liquidity to meet anticipated redemptions. The fair value of the loaned securities is monitored on a daily basis, with additional collateral obtained or refunded as the fair value of the loaned securities changes. The collateral is held by the third party banking institution, and the collateral can only be accessed in the event that the institution borrowing the securities is in default under the lending agreement. As a result of these restrictions, we consider our securities lending activities to be non-cash investing and financing activities. An indemnification agreement with the lending agent protects us in the event a borrower becomes insolvent or fails to return any of the securities on loan. The fair value of the securities on loan is included in fixed maturities and equity securities. The securities lending collateral is reported as a separate line in total assets with a related liability reflecting our obligation to return the collateral plus interest.

Similar to securities lending arrangements, securities sold under reverse repurchase agreements, whereby ACE sells securities and repurchases them at a future date for a predetermined price, are accounted for as collateralized investments and borrowings and are recorded at the contractual repurchase amounts plus accrued interest. Assets to be repurchased are the same, or substantially the same, as the assets transferred and the transferor, through right of substitution, maintains the right and ability to redeem the collateral on short notice. The fair value of the underlying securities is included in fixed maturities and equity securities. In contrast to securities lending programs, the use of cash received is not restricted. We report the obligation to return the cash as Short-term debt in the consolidated balance sheets.

Refer to Note 4 for a discussion on the determination of fair value for ACE's various investment securities.

Cash

f) Cash

Cash includes cash on hand and deposits with an original maturity of three months or less at time of purchase. Cash held by external money managers is included in Short-term investments.

We have agreements with a third party bank provider which implemented two international multi-currency notional cash pooling programs. In each program, participating ACE entities establish deposit accounts in different currencies with the bank provider and each day the credit or debit balances in every account are notionally translated into a single currency (U.S. dollars) and then notionally pooled. The bank extends overdraft credit to any participating ACE entity as needed, provided that the overall notionally-pooled balance of all accounts in each pool at the end of each day is at least zero. Actual cash balances are not physically converted and are not commingled between legal entities. Any overdraft balances incurred under this program by an ACE entity would be guaranteed by ACE Limited (up to $350 million in the aggregate). Our revolving credit facility allows for same day drawings to fund a net pool overdraft should participating ACE entities withdraw contributed funds from the pool.

Goodwill And Other Intangible Assets

g) Goodwill and other intangible assets

Goodwill represents the excess of the cost of acquisitions over the fair value of net assets acquired and is not amortized. Goodwill is assigned at acquisition to the applicable reporting unit of the acquired entities giving rise to the goodwill. Goodwill impairment tests are performed annually, or more frequently if circumstances indicate a possible impairment. For goodwill impairment testing, we use a qualitative assessment to determine whether it is more likely than not (i.e., more than a 50 percent probability) that the fair value of a reporting unit is greater than its carrying amount. If our assessment indicates less than a 50 percent probability that fair value exceeds carrying value, we quantitatively estimate a reporting unit's fair value using a consistently applied combination of the following models: an earnings multiple, a book value multiple, a discounted cash flow, or an allocated market capitalization model. The earnings and book value models apply multiples of comparable publicly traded companies to forecasted earnings or book value of each reporting unit and consider current market transactions. The discounted cash flow model applies a discount to estimated cash flows including a terminal value calculation. The market capitalization model allocates market capitalization to each reporting unit. Where appropriate, we consider the impact of a control premium. Goodwill recorded in connection with investments in partially-owned insurance companies is recorded in Investments in partially-owned insurance companies and is also measured for impairment annually.

Indefinite lived intangible assets are not subject to amortization. Finite lived intangible assets are amortized over their useful lives, generally ranging from 4 to 20 years. The carrying amounts of intangible assets are regularly reviewed for indicators of impairment. Impairment is recognized if the carrying amount is not recoverable from its undiscounted cash flows and is measured as the difference between the carrying amount and fair value.

Unpaid Losses And Loss Expenses

h) Unpaid losses and loss expenses

A liability is established for the estimated unpaid losses and loss expenses under the terms of, and with respect to, ACE's policies and agreements. These amounts include provision for both reported claims (case reserves) and IBNR claims. The methods of determining such estimates and establishing the resulting liability are reviewed regularly and any adjustments are reflected in operations in the period in which they become known. Future developments may result in losses and loss expenses materially greater or less than recorded amounts.

Except for net loss and loss expense reserves of $59 million net of discount held at December 31, 2011, representing structured settlements for which the timing and amount of future claim payments are reliably determinable, ACE does not discount its P&C loss reserves. Structured settlements represent contracts purchased from life insurance companies primarily to settle workers' compensation claims, where payments to the claimant by the life insurance company are expected to be made in the form of an annuity. ACE retains the liability to the claimant in the event that the life insurance company fails to pay. At December 31, 2011, the gross liability for the amount due to claimants was $644 million and reinsurance recoverables for amounts due from the life insurance companies was $585 million. For structured settlement contracts where payments are guaranteed regardless of claimant life expectancy, the amounts recoverable from the life insurance companies are included in Other assets, as they do not meet the requirements for reinsurance accounting. At December 31, 2011, there was $59 million included in Other assets in the consolidated balance sheets relating to structured settlements.

Included in unpaid losses and loss expenses are liabilities for asbestos and environmental (A&E) claims and expenses. These unpaid losses and loss expenses are principally related to claims arising from remediation costs associated with hazardous waste sites and bodily-injury claims related to asbestos products and environmental hazards. The estimation of these liabilities is particularly sensitive to changes in the legal environment, including specific settlements that may be used as precedents to settle future claims. However, ACE does not anticipate future changes in laws and regulations in setting its A&E reserve levels.

Prior period development arises from changes to loss estimates recognized in the current year that relate to loss reserves first reported in previous calendar years and excludes the effect of losses from the development of earned premiums from previous accident years. With respect to crop business, prior to the December 2010 acquisition of Rain and Hail Insurance Service, Inc. (Rain and Hail), reports relating to the previous crop year(s) were normally received in subsequent calendar years and this typically resulted in adjustments to the previously reported premiums, losses and loss expenses, and profit share commission. Following the acquisition, such information is available before the close of the calendar year. Commencing with the quarter ended September 30, 2009, prior period development for the crop business includes adjustments to both crop losses and loss expenses and the related crop profit share commission.

For purposes of analysis and disclosure, management views prior period development to be changes in the nominal value of loss estimates from period to period and excludes changes in loss estimates that do not arise from the emergence of claims, such as those related to uncollectible reinsurance, interest, unallocated loss adjustment expenses, or foreign currency. Accordingly, specific items excluded from prior period development include the following: gains/losses related to foreign currency remeasurement; losses recognized from the early termination or commutation of reinsurance agreements that principally relate to the time value of money; changes in the value of reinsurance business assumed reflected in losses incurred but principally related to the time value of money; and losses that arise from changes in estimates of earned premiums from prior accident years. Except for foreign currency remeasurement, which is disclosed separately, these items are included in current year losses.

Future Policy Benefits

i) Future policy benefits

The valuation of long duration contract reserves requires management to make estimates and assumptions regarding expenses, mortality, persistency, and investment yields. Such estimates are primarily based on historical experience and information provided by ceding companies and include a margin for adverse deviation. Interest rates used in calculating reserves range from less than one percent to six percent and one percent to seven percent at December 31, 2011 and 2010, respectively. Actual results could differ materially from these estimates. Management monitors actual experience, and where circumstances warrant, will revise assumptions and the related reserve estimates. Revisions are recorded in the period they are determined.

Certain of our long duration contracts have assets that do not qualify for separate account reporting under GAAP (failed separate accounts). The assets related to failed separate accounts are reported in Other investments and the offsetting liabilities are reported in Future policy benefits in the consolidated balance sheets. Changes in the fair value of failed separate account assets are reported in Other income (expense) and the offsetting movements in the failed separate account liabilities are included in Policy benefits in the consolidated statements of operations.

Assumed Reinsurance Programs Involving Minimum Benefit Guarantees Under Annuity Contracts

j) Assumed reinsurance programs involving minimum benefit guarantees under annuity contracts

ACE reinsures various death and living benefit guarantees associated with variable annuities issued primarily in the United States and Japan. Each reinsurance treaty covers variable annuities written during a limited period, typically not exceeding two years. We generally receive a monthly premium during the accumulation phase of the covered annuities (in-force) based on a percentage of either the underlying accumulated account values or the underlying accumulated guaranteed values. Depending on an annuitant's age, the accumulation phase can last many years. To limit our exposure under these programs, all reinsurance treaties include aggregate claim limits and many include an aggregate deductible.

The guarantees which are payable on death, referred to as guaranteed minimum death benefits (GMDB), principally cover shortfalls between accumulated account value at the time of an annuitant's death and either i) an annuitant's total deposits; ii) an annuitant's total deposits plus a minimum annual return; or iii) the highest accumulated account value attained at any policy anniversary date. In addition, a death benefit may be based on a formula specified in the variable annuity contract that uses a percentage of the growth of the underlying contract value. Liabilities for GMDBs are based on cumulative assessments or premiums to date multiplied by a benefit ratio that is determined by estimating the present value of benefit payments and related adjustment expenses divided by the present value of cumulative assessment or expected fees during the contract period.

Under reinsurance programs covering GLBs, we assume the risk of guaranteed minimum income benefits (GMIB) and guaranteed minimum accumulation benefits (GMAB) associated with variable annuity contracts. The GMIB risk is triggered if, at the time the contract holder elects to convert the accumulated account value to a periodic payment stream (annuitize), the accumulated account value is not sufficient to provide a guaranteed minimum level of monthly income. The GMAB risk is triggered if, at contract maturity, the contract holder's account value is less than a guaranteed minimum value. Our GLB reinsurance product meets the definition of a derivative for accounting purposes and is carried at fair value with changes in fair value recognized in income and classified as described below. As the assuming entity, we are obligated to provide coverage until the earlier of the expiration of the underlying guaranteed benefit or the treaty expiration date. Premiums received under the reinsurance treaties are classified as premium. Expected losses allocated to premiums received are classified as policy benefits and valued similar to GMDB reinsurance. Other changes in fair value, principally arising from changes in expected losses allocated to expected future premiums, are classified as Net realized gains (losses). Fair value represents management's estimate of exit price and thus includes a risk margin. We may recognize a realized loss for other changes in fair value due to adverse changes in the capital markets (i.e., declining interest rates and/or declining equity markets) and changes in policyholder behavior (i.e., increased annuitization or decreased lapse rates) although we expect the business to be profitable. We believe this presentation provides the most meaningful disclosure of changes in the underlying risk within the GLB reinsurance programs for a given reporting period. Refer to Note 5 c) for additional information.

Deposit Assets And Liabilities

k) Deposit assets and liabilities

Deposit assets arise from ceded reinsurance contracts purchased that do not transfer significant underwriting or timing risk. Under deposit accounting, consideration received or paid, excluding non-refundable fees, is recorded as a deposit asset or liability in the balance sheet as opposed to recording ceded premiums and losses in the statement of operations. Interest income on deposits, representing the consideration received or to be received in excess of cash payments related to the deposit contract, is earned based on an effective yield calculation. The calculation of the effective yield is based on the amount and timing of actual cash flows at the balance sheet date and the estimated amount and timing of future cash flows. The effective yield is recalculated periodically to reflect revised estimates of cash flows. When a change in the actual or estimated cash flows occurs, the resulting change to the carrying amount of the deposit asset is reported as income or expense. Deposit assets of $133 million and $144 million at December 31, 2011 and 2010, respectively, are reflected in Other assets in the consolidated balance sheets and the accretion of deposit assets related to interest pursuant to the effective yield calculation is reflected in Net investment income in the consolidated statements of operations.

Non-refundable fees are earned based on contract terms. Non-refundable fees paid but unearned are reflected in Other assets in the consolidated balance sheets and earned fees are reflected in Other (income) expense in the consolidated statements of operations.

Deposit liabilities include reinsurance deposit liabilities of $318 million and $351 million and contract holder deposit funds of $345 million and $70 million at December 31, 2011 and 2010, respectively. The reinsurance deposit liabilities arise from contracts sold for which there is not a significant transfer of risk. At contract inception, the deposit liability equals net cash received. An accretion rate is established based on actuarial estimates whereby the deposit liability is increased to the estimated amount payable over the contract term. The deposit accretion rate is the rate of return required to fund expected future payment obligations. We periodically reassess the estimated ultimate liability and related expected rate of return. Changes to the amount of the deposit liability are reflected through Interest expense to reflect the cumulative effect of the period the contract has been in force, and by an adjustment to the future accretion rate of the liability over the remaining estimated contract term.

Contract holder deposit funds represent a liability for investment contracts sold that do not meet the definition of an insurance contract and are sold with a guaranteed rate of return. The liability equals accumulated policy account values, which consist of the deposit payments plus credited interest, less withdrawals and amounts assessed through the end of the period.

Foreign Currency Remeasurement And Translation

l) Foreign currency remeasurement and translation

The functional currency for each of our foreign operations is generally the currency of the local operating environment. Transactions in currencies other than a foreign operation's functional currency are remeasured into the functional currency and the resulting foreign exchange gains and losses are reflected in Net realized gains (losses) in the consolidated statements of operations. Functional currency assets and liabilities are translated into the reporting currency, U.S. dollars, using period end rates of exchange and the related translation adjustments are recorded as a separate component of AOCI. Functional statement of operations amounts expressed in functional currencies are translated using average exchange rates. Gains and losses resulting from foreign currency transactions are recorded in Net realized gains (losses) in the consolidated statements of operations.

Administrative Expenses

m) Administrative expenses

Administrative expenses generally include all operating costs other than policy acquisition costs. The Insurance – North American segment manages and uses an in-house third-party claims administrator, ESIS Inc. (ESIS). ESIS performs claims management and risk control services for domestic and international organizations that self-insure P&C exposures as well as internal P&C exposures. The net operating results of ESIS are included within Administrative expenses in the consolidated statements of operations and were $21 million, $85 million, and $26 million for the years ended December 31, 2011, 2010, and 2009, respectively.

Income Taxes

n) Income taxes

Income taxes have been recorded related to those operations subject to income taxes. Deferred tax assets and liabilities result from temporary differences between the amounts recorded in the consolidated financial statements and the tax basis of our assets and liabilities. Refer to Note 8 for additional information. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance against deferred tax assets is recorded if it is more likely than not that all, or some portion, of the benefits related to deferred tax assets will not be realized. The valuation allowance assessment considers tax planning strategies, where applicable.

We recognize uncertain tax positions deemed more likely than not of being sustained upon examination. Recognized income tax positions are measured at the largest amount that is greater than 50 percent likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.

Earnings Per Share

o) Earnings per share

Basic earnings per share is calculated using the weighted-average shares outstanding including participating securities with non-forfeitable rights to dividends such as unvested restricted stock. All potentially dilutive securities including stock options are excluded from the basic earnings per share calculation. In calculating diluted earnings per share, the weighted-average shares outstanding is increased to include all potentially dilutive securities. Basic and diluted earnings per share are calculated by dividing net income available to common shareholders by the applicable weighted-average number of shares outstanding during the year.

Cash Flow Information

p) Cash flow information

Premiums received and losses paid associated with the GLB reinsurance products, which as discussed previously meet the definition of a derivative instrument for accounting purposes, are included within cash flows from operating activities in the consolidated statement of cash flows. Cash flows, such as settlements and collateral requirements, associated with all other derivative instruments are included on a net basis within cash flows from investing activities in the consolidated statement of cash flows. Purchases, sales, and maturities of short-term investments are recorded net for purposes of the consolidated statements of cash flows and are classified with cash flows related to fixed maturities.

Derivatives

q) Derivatives

ACE recognizes all derivatives at fair value in the consolidated balance sheets and participates in derivative instruments in two principal ways:

(i) To sell protection to customers as an insurance or reinsurance contract that meets the definition of a derivative for accounting purposes. For 2011 and 2010, the reinsurance of GLBs was our primary product falling into this category; and

(ii) To mitigate financial risks, principally arising from investment holdings, products sold, or assets and liabilities held in foreign currencies. For these instruments, changes in assets or liabilities measured at fair value are recorded as realized gains or losses in the consolidated statement of operations.

We did not designate any derivatives as accounting hedges during 2011, 2010, or 2009.

Share-Based Compensation

r) Share-based compensation

ACE measures and records compensation cost for all share-based payment awards at grant-date fair value. Compensation costs are recognized for share-based payment awards with only service conditions that have graded vesting schedules on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards. Refer to Note 12 for additional information.