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Short Duration Contracts | 12 Months Ended
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Dec. 31, 2023
Short Duration Contracts Disclosure [Abstract] |
Short duration contracts | The Company’s reserves for losses and loss adjustment expenses primarily relate to short-duration contracts with various characteristics (e.g., type of coverage, geography, claims duration). The Company considered such information in determining the level of disaggregation for disclosures related to its short-duration contracts, as detailed in the table below:
Reportable segment |  | Level of disaggregation |  | Included lines of business
Insurance |  | Property energy, marine and aviation |  | Property energy, marine and aviation
|  | Third party occurrence business |  | Excess and surplus casualty (excluding contract binding); construction and national accounts; and other (including alternative market risks, excess workers’ compensation and employer’s liability insurance coverages)
|  | Third party claims-made business |  | Professional lines
|  | Multi-line and other specialty |  | Programs; contract binding (part of excess and surplus casualty); travel, accident and health; warranty and lenders solutions; and other (c ontract and commercial surety coverages)
Reinsurance |  | Casualty |  | Casualty
|  | Property catastrophe |  | Property catastrophe
|  | Property excluding property catastrophe |  | Property excluding property catastrophe
|  | Marine and aviation |  | Marine and aviation
|  | Other specialty |  | Other specialty
Mortgage |  | Direct mortgage insurance in the U.S. |  | Mortgage insurance on U.S. primary exposures
The Company determined the following to be insignificant for disclosure purposes: (i) certain mortgage business, including non-U.S. primary business, second lien and student loan exposures, global mortgage reinsurance and participation in various GSE credit risk-sharing products and (ii) certain reinsurance business, including casualty clash and non-traditional lines. Such amounts are included as reconciling items. The Company is required to establish reserves for losses and loss adjustment expenses (“Loss Reserves”) that arise from the business the Company underwrites. Loss Reserves for the insurance, reinsurance and mortgage segments represent estimates of future amounts required to pay losses and loss adjustment expenses for insured or reinsured events which have occurred at or before the balance sheet date. Loss Reserves do not reflect contingency reserve allowances to account for future loss occurrences. Losses arising from future events will be estimated and recognized at the time the losses are incurred and could be substantial. Insurance Segment Loss Reserves for the insurance segment are comprised of estimated amounts for (1) reported losses (“case reserves”) and (2) incurred but not reported losses (“IBNR reserves”). Generally, claims personnel determine whether to establish a case reserve for the estimated amount of the ultimate settlement of individual claims. The estimate reflects the judgment of claims personnel based on general corporate reserving practices, the experience and knowledge of such personnel regarding the nature and value of the specific type of claim and, where appropriate, advice of counsel. The Company also contracts with a number of outside third party administrators in the claims process who, in certain cases, have limited authority to establish case reserves. The work of such administrators is reviewed and monitored by our claims personnel. Loss Reserves are also established to provide for loss adjustment expenses and represent the estimated expense of settling claims, including legal and other fees and the general expenses of administering the claims adjustment process. Periodically, adjustments to the case reserves may be made as additional information is reported or payments are made. IBNR reserves are established to provide for incurred claims which have not yet been reported at the balance sheet date as well as to adjust for any projected variance in case reserving. Actuaries estimate ultimate losses and loss adjustment expenses using various generally accepted actuarial methods applied to known losses and other relevant information. Like case reserves, IBNR reserves are adjusted as additional information becomes known or payments are made. The process of estimating reserves involves a considerable degree of judgment by management and, as of any given date, is inherently uncertain. Ultimate losses and loss adjustment expenses are generally determined by projection of claim emergence and settlement patterns observed in the past that can reasonably be expected to persist into the future. In forecasting ultimate losses and loss adjustment expenses with respect to any line of business, past experience with respect to that line of business is the primary resource, developed through both industry and company experience, but cannot be relied upon in isolation. Uncertainties in estimating ultimate losses and loss adjustment expenses are magnified by the length of the time lag between when a claim actually occurs and when it is reported and settled. This time lag is sometimes referred to as the “claim-tail.” During this period additional facts regarding coverages written in prior accident years, as well as about actual claims and trends, may become known and, as a result, may lead to adjustments of the related Loss Reserves. If the Company determines that an adjustment is appropriate, the adjustment is recorded in the accounting period in which such determination is made. Accordingly, should Loss Reserves need to be increased or decreased in the future from amounts currently established, future results of operations would be negatively or positively impacted respectively. The Company authorizes managing general agents, general agents and other producers to write program business on the Company’s behalf within prescribed underwriting authorities. This delegated authority process introduces additional complexity to the actuarial determination of unpaid future losses and loss adjustment expenses. In order to monitor adherence to the underwriting guidelines given to such parties, the Company periodically performs underwriting and claims due diligence reviews. In determining ultimate losses and loss adjustment expenses, the cost to indemnify claimants, provide needed legal defense and other services for insureds and administer the investigation and adjustment of claims are considered. These claim costs are influenced by many factors that change over time, such as expanded coverage definitions as a result of new court decisions, inflation in costs to repair or replace damaged property, inflation in the cost of medical services and legislated changes in statutory benefits, as well as by the particular, unique facts that pertain to each claim. As a result, the rate at which claims arose in the past and the costs to settle them may not always be representative of what will occur in the future. The factors influencing changes in claim costs are often difficult to isolate or quantify and developments in paid and incurred losses from historical trends are frequently subject to multiple and conflicting interpretations. Changes in coverage terms or claims handling practices may also cause future experience and/or development patterns to vary from the past. A key objective of actuaries in developing estimates of ultimate losses and loss adjustment expenses, and resulting IBNR reserves, is to identify aberrations and systemic changes occurring within historical experience and adjust for them so that the future can be projected more reliably. Because of the factors previously discussed, this process requires the substantial use of informed judgment and is inherently uncertain. Although Loss Reserves are initially determined based on underwriting and pricing analyses, the Company’s insurance segment applies several generally accepted actuarial methods, as discussed below, on a quarterly basis to evaluate the Loss Reserves, in addition to the expected loss method, in particular for Loss Reserves from more mature accident years (the year in which a loss occurred). Each quarter, as part of the reserving process, the segments’ actuaries reaffirm that the assumptions used in the reserving process continue to form a sound basis for the projection of liabilities. If actual loss activity differs substantially from expectations based on historical information, an adjustment to Loss Reserves may be supported. The Company places more or less reliance on a particular actuarial method based on the facts and circumstances at the time the estimates of Loss Reserves are made. These methods generally fall into one of the following categories or are hybrids of one or more of the following categories: •Expected loss methods - these methods are based on the assumption that ultimate losses vary proportionately with premiums. Expected loss and loss adjustment expense ratios are typically developed based upon the information derived by underwriters and actuaries during the initial pricing of the business, supplemented by industry data available from organizations, such as statistical bureaus and consulting firms, where appropriate. These ratios consider, among other things, rate increases and changes in terms and conditions that have been observed in the market. Expected loss methods are useful for estimating ultimate losses and loss adjustment expenses in the early years of long-tailed lines of business, when little or no paid or incurred loss information is available, and is commonly applied when limited loss experience exists for a company. •Historical incurred loss development methods - these methods assume that the ratio of losses in one period to losses in an earlier period will remain constant in the future. These methods use incurred losses (i.e., the sum of cumulative historical loss payments plus outstanding case reserves) over discrete periods of time to estimate future losses. Historical incurred loss development methods may be preferable to historical paid loss development methods because they explicitly take into account open cases and the claims adjusters’ evaluations of the cost to settle all known claims. However, historical incurred loss development methods necessarily assume that case reserving practices are consistently applied over time. Therefore, when there have been significant changes in how case reserves are established, using incurred loss data to project ultimate losses may be less reliable than other methods. •Historical paid loss development methods - these methods, like historical incurred loss development methods, assume that the ratio of losses in one period to losses in an earlier period will remain constant. These methods use historical loss payments over discrete periods of time to estimate future losses and necessarily assume that factors that have affected paid losses in the past, such as inflation or the effects of litigation, will remain constant in the future. Because historical paid loss development methods do not use incurred losses to estimate ultimate losses, they may be more reliable than the other methods that use incurred losses in situations where there are significant changes in how incurred losses are established by a company’s claims adjusters. However, historical paid loss development methods are more leveraged (meaning that small changes in payments have a larger impact on estimates of ultimate losses) than actuarial methods that use incurred losses because cumulative loss payments take much longer to equal the expected ultimate losses than cumulative incurred amounts. In addition, and for similar reasons, historical paid loss development methods are often slow to react to situations when new or different factors arise than those that have affected paid losses in the past. •Adjusted historical paid and incurred loss development methods - these methods take traditional historical paid and incurred loss development methods and adjust them for the estimated impact of changes from the past in factors such as inflation, the speed of claim payments or the adequacy of case reserves. Adjusted historical paid and incurred loss development methods are often more reliable methods of predicting ultimate losses in periods of significant change, provided the actuaries can develop methods to reasonably quantify the impact of changes. As such, these methods utilize more judgment than historical paid and incurred loss development methods. •Bornhuetter-Ferguson (“B-F”) paid and incurred loss methods - these methods utilize actual paid and incurred losses and expected patterns of paid and incurred losses, taking the initial expected ultimate losses into account to determine an estimate of expected ultimate losses. The B-F paid and incurred loss methods are useful when there are few reported claims and a relatively less stable pattern of reported losses. •Frequency-Severity methods - These methods utilize actual paid and incurred claim experience, but break the data down into its component pieces: claim counts, often expressed as a ratio to exposure or premium (frequency), and average claim size (severity). The component pieces are projected to an ultimate level and multiplied together to result in an estimate of ultimate loss. These methods are especially useful when the severity of claims can be confined to a relatively stable range of estimated ultimate average claim value. •Additional analyses - other methodologies are often used in the reserving process for specific types of claims or events, such as catastrophic or other specific major events. These include vendor catastrophe models, which are typically used in the estimation of Loss Reserves at the early stage of known catastrophic events before information has been reported to an insurer or reinsurer. In the initial reserving process for short-tail insurance lines (consisting of property, energy, marine and aviation and other exposures including travel, accident and health, and warranty and lenders solutions), the Company relies on a combination of the reserving methods discussed above. For catastrophe-exposed business, the reserving process also includes the usage of catastrophe models for known events and a heavy reliance on analysis of individual catastrophic events and management judgment. The development of losses on short-tail business can be unstable, especially for policies characterized by high severity, low frequency losses. As time passes, for a given accident year, additional weight is given to the paid and incurred B-F loss development methods and eventually to the historical paid and incurred loss development methods in the reserving process. The Company makes a number of key assumptions in their reserving process, including that historical paid and reported development patterns are stable, catastrophe models provide useful information about our exposure to catastrophic events that have occurred and underwriters’ judgment as to potential loss exposures can be relied on. The expected loss ratios used in the initial reserving process for short-tail business have varied over time due to changes in pricing, reinsurance structure, estimates of catastrophe losses, policy changes (such as attachment points, class and limits) and geographical distribution. As losses in short-tail lines are reported relatively quickly, expected loss ratios are selected for the current accident year based upon actual attritional loss ratios for earlier accident years, adjusted for rate changes, inflation, changes in reinsurance programs and expected attritional losses based on modeling. Furthermore, ultimate losses for short-tail business are known in a reasonably short period of time. In the initial reserving process for medium-tail and long-tail insurance lines (consisting of third party occurrence business, third party claims made business, and other exposures including surety, programs and contract binding exposures), the Company primarily relies on the expected loss method. The development of the Company’s medium-tail and long-tail business may be unstable, especially if there are high severity major events, as a portion of the Company’s casualty business is in high excess layers. As time passes, for a given accident year, additional weight is given to the paid and incurred B-F loss development methods and historical paid and incurred loss development methods in the reserving process. The Company makes a number of key assumptions in reserving for medium-tail and long-tail lines, including that the pricing loss ratio is the best estimate of the ultimate loss ratio at the time the policy is entered into, that the loss development patterns, which are based on a combination of company and industry loss development patterns and adjusted to reflect differences in the insurance segment’s mix of business, are reasonable and that claims personnel and underwriters analyses of our exposure to major events are assumed to be the best estimate of exposure to the known claims on those events. The expected loss ratios used in the initial reserving process for medium-tail and long-tail business for recent accident years have varied over time, in some cases significantly, from earlier accident years. As the credibility of historical experience for earlier accident years increases, the experience from these accident years will be given a greater weighting in the actuarial analysis to determine future accident year expected loss ratios, adjusted for changes in pricing, loss trends, terms and conditions and reinsurance structure. From time to time, the Company enters into loss portfolio transfer and adverse development cover reinsurance agreements accounted for as retroactive reinsurance. These agreements transfer Loss Reserves and future favorable or adverse development on certain runoff programs and certain third party occurrence business, within multi-line and other specialty business (the “Covered Lines”). As incurred losses and allocated loss adjustment expenses for the Covered Lines are ceded to the reinsurer, the Company is not exposed to changes in the amount, timing and uncertainty of cash flows arising from the Covered Lines. To avoid distortion, the incurred losses and allocated loss adjustment expenses and cumulative paid losses and loss adjustment expenses for the Covered Lines are excluded entirely from the tables below. Unpaid loss and loss adjustment expenses recoverable at December 31, 2023 included $225 million related to such reinsurance agreements. The following tables present information on the insurance segment’s short-duration insurance contracts:
Property, energy, marine and aviation (in millions except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 148 |  |  | $ | 146 |  |  | $ | 147 |  |  | $ | 136 |  |  | $ | 132 |  |  | $ | 134 |  |  | $ | 135 |  |  | $ | 135 |  |  | $ | 134 |  |  | $ | 133 |  |  | $ | 2 |  |  | 3,871 |
2015 |  |  |  | 112 |  |  | 110 |  |  | 104 |  |  | 102 |  |  | 98 |  |  | 92 |  |  | 92 |  |  | 91 |  |  | 89 |  |  | 2 |  |  | 4,530 |
2016 |  |  |  |  |  | 104 |  |  | 101 |  |  | 105 |  |  | 100 |  |  | 96 |  |  | 92 |  |  | 88 |  |  | 88 |  |  | — |  |  | 6,171 |
2017 |  |  |  |  |  |  |  | 281 |  |  | 246 |  |  | 236 |  |  | 230 |  |  | 231 |  |  | 225 |  |  | 225 |  |  | 1 |  |  | 6,475 |
2018 |  |  |  |  |  |  |  |  |  | 181 |  |  | 186 |  |  | 174 |  |  | 170 |  |  | 170 |  |  | 172 |  |  | 5 |  |  | 5,077 |
2019 |  |  |  |  |  |  |  |  |  |  |  | 179 |  |  | 179 |  |  | 165 |  |  | 161 |  |  | 159 |  |  | (1) |  |  | 7,018 |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 359 |  |  | 329 |  |  | 336 |  |  | 333 |  |  | 9 |  |  | 8,212 |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 427 |  |  | 429 |  |  | 423 |  |  | 41 |  |  | 8,807 |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 522 |  |  | 495 |  |  | 74 |  |  | 13,274 |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 571 |  |  | 275 |  |  | 13,682 |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 2,688 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 26 |  |  | $ | 54 |  |  | $ | 78 |  |  | $ | 84 |  |  | $ | 88 |  |  | $ | 98 |  |  | $ | 115 |  |  | $ | 122 |  |  | $ | 123 |  |  | $ | 125 |  |  |  |  |
2015 |  |  |  | 24 |  |  | 65 |  |  | 76 |  |  | 86 |  |  | 88 |  |  | 86 |  |  | 87 |  |  | 88 |  |  | 86 |  |  |  |  |
2016 |  |  |  |  |  | 25 |  |  | 83 |  |  | 98 |  |  | 97 |  |  | 95 |  |  | 91 |  |  | 87 |  |  | 87 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 30 |  |  | 140 |  |  | 196 |  |  | 212 |  |  | 216 |  |  | 218 |  |  | 220 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 30 |  |  | 102 |  |  | 135 |  |  | 143 |  |  | 150 |  |  | 154 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 26 |  |  | 105 |  |  | 134 |  |  | 139 |  |  | 148 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 56 |  |  | 194 |  |  | 251 |  |  | 293 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 90 |  |  | 268 |  |  | 343 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100 |  |  | 276 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 146 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | Total |  | 1,878 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 14 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 824 |  |  |  |  |
Third party occurrence business (in millions except claim count)
|  | Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 330 |  |  | $ | 336 |  |  | $ | 339 |  |  | $ | 343 |  |  | $ | 339 |  |  | $ | 344 |  |  | $ | 343 |  |  | $ | 343 |  |  | $ | 345 |  |  | $ | 344 |  |  | $ | 49 |  |  | 75,679 |
2015 |  |  |  | 359 |  |  | 392 |  |  | 399 |  |  | 392 |  |  | 391 |  |  | 382 |  |  | 386 |  |  | 379 |  |  | 377 |  |  | 66 |  |  | 78,689 |
2016 |  |  |  |  |  | 390 |  |  | 394 |  |  | 406 |  |  | 399 |  |  | 375 |  |  | 368 |  |  | 363 |  |  | 352 |  |  | 77 |  |  | 78,883 |
2017 |  |  |  |  |  |  |  | 417 |  |  | 418 |  |  | 422 |  |  | 412 |  |  | 407 |  |  | 406 |  |  | 405 |  |  | 100 |  |  | 84,687 |
2018 |  |  |  |  |  |  |  |  |  | 430 |  |  | 453 |  |  | 451 |  |  | 451 |  |  | 459 |  |  | 462 |  |  | 127 |  |  | 78,320 |
2019 |  |  |  |  |  |  |  |  |  |  |  | 456 |  |  | 487 |  |  | 481 |  |  | 471 |  |  | 470 |  |  | 154 |  |  | 86,139 |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 607 |  |  | 616 |  |  | 640 |  |  | 632 |  |  | 226 |  |  | 92,279 |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 622 |  |  | 663 |  |  | 659 |  |  | 290 |  |  | 92,672 |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 688 |  |  | 726 |  |  | 513 |  |  | 92,564 |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 877 |  |  | 750 |  |  | 72,833 |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 5,304 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 9 |  |  | $ | 40 |  |  | $ | 71 |  |  | $ | 113 |  |  | $ | 162 |  |  | $ | 191 |  |  | $ | 211 |  |  | $ | 224 |  |  | $ | 237 |  |  | $ | 257 |  |  |  |  |
2015 |  |  |  | 11 |  |  | 45 |  |  | 88 |  |  | 139 |  |  | 182 |  |  | 212 |  |  | 227 |  |  | 249 |  |  | 268 |  |  |  |  |
2016 |  |  |  |  |  | 12 |  |  | 42 |  |  | 88 |  |  | 137 |  |  | 165 |  |  | 195 |  |  | 215 |  |  | 231 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 13 |  |  | 52 |  |  | 100 |  |  | 135 |  |  | 165 |  |  | 221 |  |  | 247 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 17 |  |  | 64 |  |  | 115 |  |  | 154 |  |  | 200 |  |  | 247 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 18 |  |  | 73 |  |  | 122 |  |  | 173 |  |  | 214 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 24 |  |  | 77 |  |  | 155 |  |  | 235 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 26 |  |  | 91 |  |  | 174 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 24 |  |  | 85 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 32 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | Total |  | 1,990 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 287 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 3,601 |  |  |  |  |
Third party claims-made business (in millions except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 264 |  |  | $ | 279 |  |  | $ | 299 |  |  | $ | 279 |  |  | $ | 281 |  |  | $ | 297 |  |  | $ | 291 |  |  | $ | 288 |  |  | $ | 296 |  |  | $ | 287 |  |  | $ | 14 |  |  | 14,494 |
2015 |  |  |  | 259 |  |  | 277 |  |  | 276 |  |  | 260 |  |  | 255 |  |  | 252 |  |  | 268 |  |  | 267 |  |  | 274 |  |  | 13 |  |  | 13,932 |
2016 |  |  |  |  |  | 275 |  |  | 291 |  |  | 308 |  |  | 314 |  |  | 322 |  |  | 327 |  |  | 330 |  |  | 327 |  |  | 18 |  |  | 14,912 |
2017 |  |  |  |  |  |  |  | 270 |  |  | 286 |  |  | 312 |  |  | 308 |  |  | 323 |  |  | 317 |  |  | 338 |  |  | 48 |  |  | 15,473 |
2018 |  |  |  |  |  |  |  |  |  | 273 |  |  | 314 |  |  | 320 |  |  | 336 |  |  | 347 |  |  | 367 |  |  | 44 |  |  | 17,098 |
2019 |  |  |  |  |  |  |  |  |  |  |  | 289 |  |  | 317 |  |  | 317 |  |  | 322 |  |  | 330 |  |  | 66 |  |  | 15,879 |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 383 |  |  | 413 |  |  | 423 |  |  | 446 |  |  | 118 |  |  | 15,239 |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 515 |  |  | 518 |  |  | 499 |  |  | 254 |  |  | 16,323 |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 669 |  |  | 655 |  |  | 448 |  |  | 18,563 |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 811 |  |  | 641 |  |  | 20,494 |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 4,334 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 14 |  |  | $ | 63 |  |  | $ | 129 |  |  | $ | 173 |  |  | $ | 207 |  |  | $ | 229 |  |  | $ | 243 |  |  | $ | 249 |  |  | $ | 260 |  |  | $ | 266 |  |  |  |  |
2015 |  |  |  | 9 |  |  | 52 |  |  | 100 |  |  | 126 |  |  | 174 |  |  | 193 |  |  | 217 |  |  | 221 |  |  | 242 |  |  |  |  |
2016 |  |  |  |  |  | 11 |  |  | 68 |  |  | 127 |  |  | 158 |  |  | 205 |  |  | 242 |  |  | 257 |  |  | 296 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 9 |  |  | 68 |  |  | 113 |  |  | 143 |  |  | 196 |  |  | 233 |  |  | 258 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 12 |  |  | 68 |  |  | 118 |  |  | 158 |  |  | 208 |  |  | 258 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 12 |  |  | 65 |  |  | 122 |  |  | 155 |  |  | 197 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 17 |  |  | 87 |  |  | 152 |  |  | 215 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 23 |  |  | 90 |  |  | 163 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 25 |  |  | 100 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 64 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | Total |  | 2,059 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 77 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 2,352 |  |  |  |  |
Multi-line and other specialty (in millions except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 302 |  |  | $ | 326 |  |  | $ | 318 |  |  | $ | 318 |  |  | $ | 317 |  |  | $ | 313 |  |  | $ | 310 |  |  | $ | 309 |  |  | $ | 311 |  |  | $ | 310 |  |  | $ | 4 |  |  | 148,702 |
2015 |  |  |  | 335 |  |  | 358 |  |  | 357 |  |  | 365 |  |  | 357 |  |  | 349 |  |  | 347 |  |  | 345 |  |  | 345 |  |  | 5 |  |  | 180,468 |
2016 |  |  |  |  |  | 409 |  |  | 431 |  |  | 428 |  |  | 416 |  |  | 410 |  |  | 408 |  |  | 409 |  |  | 406 |  |  | 7 |  |  | 192,955 |
2017 |  |  |  |  |  |  |  | 482 |  |  | 501 |  |  | 491 |  |  | 501 |  |  | 504 |  |  | 513 |  |  | 516 |  |  | 9 |  |  | 235,539 |
2018 |  |  |  |  |  |  |  |  |  | 512 |  |  | 565 |  |  | 563 |  |  | 565 |  |  | 565 |  |  | 565 |  |  | 14 |  |  | 260,995 |
2019 |  |  |  |  |  |  |  |  |  |  |  | 567 |  |  | 612 |  |  | 640 |  |  | 651 |  |  | 657 |  |  | 21 |  |  | 252,766 |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 618 |  |  | 569 |  |  | 515 |  |  | 517 |  |  | 44 |  |  | 166,357 |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 635 |  |  | 619 |  |  | 614 |  |  | 76 |  |  | 114,447 |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 678 |  |  | 642 |  |  | 157 |  |  | 143,264 |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 817 |  |  | 450 |  |  | 118,241 |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 5,389 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 108 |  |  | $ | 197 |  |  | $ | 234 |  |  | $ | 267 |  |  | $ | 281 |  |  | $ | 292 |  |  | $ | 293 |  |  | $ | 295 |  |  | $ | 296 |  |  | $ | 297 |  |  |  |  |
2015 |  |  |  | 138 |  |  | 236 |  |  | 278 |  |  | 306 |  |  | 321 |  |  | 327 |  |  | 330 |  |  | 331 |  |  | 333 |  |  |  |  |
2016 |  |  |  |  |  | 176 |  |  | 305 |  |  | 342 |  |  | 363 |  |  | 379 |  |  | 385 |  |  | 390 |  |  | 392 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 181 |  |  | 342 |  |  | 381 |  |  | 423 |  |  | 446 |  |  | 472 |  |  | 480 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 212 |  |  | 389 |  |  | 443 |  |  | 480 |  |  | 509 |  |  | 527 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 212 |  |  | 386 |  |  | 487 |  |  | 549 |  |  | 577 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 172 |  |  | 309 |  |  | 359 |  |  | 406 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 157 |  |  | 335 |  |  | 428 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 177 |  |  | 371 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 254 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | Total |  | 4,065 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 24 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 1,348 |  |  |  |  |
The following table presents the average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance, as of December 31, 2023:
|  | Average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance
|  | Year 1 |  | Year 2 |  | Year 3 |  | Year 4 |  | Year 5 |  | Year 6 |  | Year 7 |  | Year 8 |  | Year 9 |  | Year 10
Property, energy, marine and aviation |  | 20.5 | % |  | 43.7 | % |  | 18.1 | % |  | 6.0 | % |  | 2.2 | % |  | 1.0 | % |  | 2.6 | % |  | 1.9 | % |  | (0.4) | % |  | 1.5 | %
Third party occurrence business |  | 3.5 | % |  | 9.4 | % |  | 11.5 | % |  | 11.4 | % |  | 9.9 | % |  | 9.8 | % |  | 5.6 | % |  | 4.6 | % |  | 4.4 | % |  | 5.6 | %
Third party claims-made business |  | 4.1 | % |  | 15.5 | % |  | 16.5 | % |  | 11.1 | % |  | 14.3 | % |  | 10.1 | % |  | 6.3 | % |  | 5.2 | % |  | 5.7 | % |  | 2.0 | %
Multi-line and other specialty |  | 34.0 | % |  | 29.3 | % |  | 11.3 | % |  | 8.2 | % |  | 4.5 | % |  | 2.9 | % |  | 1.1 | % |  | 0.4 | % |  | 0.4 | % |  | 0.5 | %
Reinsurance Segment Loss Reserves for the Company’s reinsurance segment are comprised of (1) case reserves, (2) additional case reserves (“ACRs”) and (3) IBNR reserves. The Company receives reports of claims notices from ceding companies and records case reserves based upon the amount of reserves recommended by the ceding company. Case reserves may be supplemented by ACRs, which may be estimated by the Company’s claims personnel ahead of official notification from the ceding company, or when judgment regarding the size or severity of the known event differs from the ceding company. In certain instances, the Company establishes ACRs even when the ceding company does not report any liability on a known event. In addition, specific claim information reported by ceding companies or obtained through claim audits can alert the Company to emerging trends such as changing legal interpretations of coverage and liability, claims from unexpected sources or classes of business, and significant changes in the frequency or severity of individual claims. Such information is often used in the process of estimating IBNR reserves. IBNR reserves are established to provide for incurred claims which have not yet been reported at the balance sheet date as well as to adjust for any projected variance in case reserving. Actuaries estimate ultimate losses and loss adjustment expenses using various generally accepted actuarial methods applied to known losses and other relevant information. Like case reserves, IBNR reserves are adjusted as additional information becomes known or payments are made. The process of estimating Loss Reserves involves a considerable degree of judgment by management and, as of any given date, is inherently uncertain. The estimation of Loss Reserves for the reinsurance segment is subject to the same risk factors as the estimation of Loss Reserves for the insurance segment. In addition, the inherent uncertainties of estimating such reserves are even greater for reinsurers, due primarily to the following factors: (1) the claim-tail for reinsurers is generally longer because claims are first reported to the ceding company and then to the reinsurer through one or more intermediaries, (2) the reliance on premium estimates, where reports have not been received from the ceding company, in the reserving process, (3) the potential for writing a number of reinsurance contracts with different ceding companies with the same exposure to a single loss event, (4) the diversity of loss development patterns among different types of reinsurance contracts, (5) the necessary reliance on the ceding companies for information regarding reported claims and (6) the differing reserving practices among ceding companies. Ultimate losses and loss adjustment expenses are generally determined by projection of claim emergence and settlement patterns observed in the past that can reasonably be expected to persist into the future. As with the insurance segment, the process of estimating Loss Reserves for the reinsurance segment involves a considerable degree of judgment by management and, as of any given date, is inherently uncertain. As discussed above, such uncertainty is greater for reinsurers compared to insurers. As a result, our reinsurance operations obtain information from numerous sources to assist in the process. Pricing actuaries from the reinsurance segment devote considerable effort to understanding and analyzing a ceding company’s operations and loss history during the underwriting of the business, using a combination of ceding company and industry statistics. Such statistics normally include historical premium and loss data by class of business, individual claim information for larger claims, distributions of insurance limits provided, loss reporting and payment patterns, and rate change history. This analysis is used to project expected loss ratios for each treaty during the upcoming contract period. As mentioned above, there can be a considerable time lag from the time a claim is reported to a ceding company to the time it is reported to the reinsurer. The lag can be several years in some cases and may be attributed to a number of reasons, including the time it takes to investigate a claim, delays associated with the litigation process, the deterioration in a claimant’s physical condition many years after an accident occurs, the case reserving approach of the ceding company, etc. In the reserving process, the Company assumes that such lags are predictable, on average, over time and therefore the lags are contemplated in the loss reporting patterns used in their actuarial methods. This means that the reinsurance segment must rely on estimates for a longer period of time than does an insurance company. Backlogs in the recording of assumed reinsurance can also complicate the accuracy of loss reserve estimation. As of December 31, 2023 there were no significant backlogs related to the processing of assumed reinsurance information at our reinsurance operations. The reinsurance segment relies heavily on information reported by ceding companies, as discussed above. In order to determine the accuracy and completeness of such information, underwriters, actuaries, and claims personnel often perform audits of ceding companies and regularly review information received from ceding companies for unusual or unexpected results. Material findings are usually discussed with the ceding companies. The Company sometimes encounters situations where they determine that a claim presentation from a ceding company is not in accordance with contract terms. In these situations, the Company attempts to resolve the dispute with the ceding company. Most situations are resolved amicably and without the need for litigation or arbitration. However, in the infrequent situations where a resolution is not possible, the Company will vigorously defend its position in such disputes. Although Loss Reserves are initially determined based on underwriting and pricing analysis, the Company applies several generally accepted actuarial methods, as discussed above, on a quarterly basis to evaluate its Loss Reserves in addition to the expected loss method, in particular for reserves from more mature underwriting years (the year in which business is underwritten). Each quarter, as part of the reserving process, the Company’s actuaries reaffirm that the assumptions used in the reserving process continue to form a sound basis for projection of liabilities. If actual loss activity differs substantially from expectations based on historical information, an adjustment to Loss Reserves may be supported. Estimated Loss Reserves for more mature underwriting years are now based more on actual loss activity and historical patterns than on the initial assumptions based on pricing indications. More recent underwriting years rely more heavily on internal pricing assumptions. The Company places more or less reliance on a particular actuarial method based on the facts and circumstances at the time the estimates of Loss Reserves are made. In the initial reserving process for short-tail reinsurance lines (consisting of property excluding property catastrophe and property catastrophe exposures), the Company relies on a combination of the reserving methods discussed above. For known catastrophic events, the reserving process also includes the usage of catastrophe models and a heavy reliance on analysis which includes ceding company inquiries and management judgment. The development of property losses may be unstable, especially where there is high catastrophic exposure, may be characterized by high severity, low frequency losses for excess and catastrophe-exposed business and may be highly correlated across contracts. As time passes, for a given underwriting year, additional weight is given to the paid and incurred B-F loss development methods and historical paid and incurred loss development methods in the reserving process. The Company makes a number of key assumptions in reserving for short-tail lines, including that historical paid and reported development patterns are stable, catastrophe models provide useful information about our exposure to catastrophic events that have occurred and our underwriters’ judgment and guidance received from ceding companies as to potential loss exposures may be relied on. The expected loss ratios used in the initial reserving process for property exposures have varied over time due to changes in pricing, reinsurance structure, estimates of catastrophe losses, terms and conditions and geographical distribution. As losses in property lines are reported relatively quickly, expected loss ratios are selected for the current underwriting year incorporating the experience for earlier underwriting years, adjusted for rate changes, inflation, changes in reinsurance programs, expectations about present and future market conditions and expected attritional losses based on modeling. Due to the short-tail nature of property business, reported loss experience emerges quickly and ultimate losses are known in a reasonably short period of time. In the initial reserving process for medium-tail and long-tail reinsurance lines (consisting of casualty, other specialty, marine and aviation and other exposures), the Company primarily relies on the expected loss method. The development of medium-tail and long-tail business may be unstable, especially if there are high severity major events, with business written on an excess of loss basis typically having a longer tail than business written on a pro rata basis. As time passes, for a given underwriting year, additional weight is given to the paid and incurred B-F loss development methods and eventually to the historical paid and incurred loss development methods in the reserving process. Our reinsurance operations make a number of key assumptions in reserving for medium-tail and long-tail lines, including that the pricing loss ratio is the best estimate of the ultimate loss ratio at the time the contract is entered into, historical paid and reported development patterns are stable and claims personnel and underwriters’ analyses of our exposure to major events are our best estimate of our exposure to the known claims on those events. The expected loss ratios used in our reinsurance operations’ initial reserving process for medium-tail and long-tail contracts have varied over time due to changes in pricing, terms and conditions and reinsurance structure. As the credibility of historical experience for earlier underwriting years increases, the experience from these underwriting years is used in the actuarial analysis to determine future underwriting year expected loss ratios, adjusted for changes in pricing, loss trends, terms and conditions and reinsurance structure. The following tables present information on the reinsurance segment’s short-duration insurance contracts:
Casualty (in millions)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 215 |  |  | $ | 220 |  |  | $ | 217 |  |  | $ | 230 |  |  | $ | 227 |  |  | $ | 237 |  |  | $ | 237 |  |  | $ | 234 |  |  | $ | 234 |  |  | $ | 241 |  |  | $ | 33 |  |  | N/A
2015 |  |  |  | 220 |  |  | 219 |  |  | 228 |  |  | 235 |  |  | 239 |  |  | 246 |  |  | 249 |  |  | 251 |  |  | 260 |  |  | 44 |  |  | N/A
2016 |  |  |  |  |  | 212 |  |  | 224 |  |  | 247 |  |  | 262 |  |  | 269 |  |  | 268 |  |  | 272 |  |  | 281 |  |  | 45 |  |  | N/A
2017 |  |  |  |  |  |  |  | 267 |  |  | 254 |  |  | 270 |  |  | 297 |  |  | 309 |  |  | 316 |  |  | 330 |  |  | 53 |  |  | N/A
2018 |  |  |  |  |  |  |  |  |  | 276 |  |  | 289 |  |  | 281 |  |  | 286 |  |  | 298 |  |  | 308 |  |  | 50 |  |  | N/A
2019 |  |  |  |  |  |  |  |  |  |  |  | 330 |  |  | 341 |  |  | 367 |  |  | 379 |  |  | 400 |  |  | 84 |  |  | N/A
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 382 |  |  | 371 |  |  | 354 |  |  | 372 |  |  | 163 |  |  | N/A
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 439 |  |  | 434 |  |  | 425 |  |  | 205 |  |  | N/A
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 547 |  |  | 527 |  |  | 390 |  |  | N/A
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 657 |  |  | 568 |  |  | N/A
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 3,801 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 4 |  |  | $ | 16 |  |  | $ | 41 |  |  | $ | 63 |  |  | $ | 91 |  |  | $ | 114 |  |  | $ | 134 |  |  | $ | 145 |  |  | $ | 153 |  |  | $ | 160 |  |  |  |  |
2015 |  |  |  | 4 |  |  | 20 |  |  | 47 |  |  | 71 |  |  | 96 |  |  | 120 |  |  | 137 |  |  | 152 |  |  | 170 |  |  |  |  |
2016 |  |  |  |  |  | 6 |  |  | 26 |  |  | 52 |  |  | 87 |  |  | 113 |  |  | 132 |  |  | 157 |  |  | 172 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 6 |  |  | 30 |  |  | 64 |  |  | 113 |  |  | 137 |  |  | 164 |  |  | 189 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 8 |  |  | 31 |  |  | 106 |  |  | 129 |  |  | 155 |  |  | 182 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 16 |  |  | 58 |  |  | 97 |  |  | 130 |  |  | 219 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 18 |  |  | 50 |  |  | 90 |  |  | 132 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 15 |  |  | 53 |  |  | 102 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 18 |  |  | 61 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 18 |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | 1,405 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 310 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 2,706 |  |  |  |  |
Property catastrophe (in millions)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 44 |  |  | $ | 30 |  |  | $ | 25 |  |  | $ | 22 |  |  | $ | 20 |  |  | $ | 20 |  |  | $ | 19 |  |  | $ | 19 |  |  | $ | 19 |  |  | $ | 19 |  |  | $ | — |  |  | N/A
2015 |  |  |  | 33 |  |  | 18 |  |  | 12 |  |  | 6 |  |  | 4 |  |  | 3 |  |  | 3 |  |  | 3 |  |  | 3 |  |  | — |  |  | N/A
2016 |  |  |  |  |  | 24 |  |  | 17 |  |  | 13 |  |  | 9 |  |  | 7 |  |  | 6 |  |  | 5 |  |  | 5 |  |  | 1 |  |  | N/A
2017 |  |  |  |  |  |  |  | 86 |  |  | 54 |  |  | 50 |  |  | 36 |  |  | 24 |  |  | 21 |  |  | 22 |  |  | (1) |  |  | N/A
2018 |  |  |  |  |  |  |  |  |  | 71 |  |  | 49 |  |  | 30 |  |  | 17 |  |  | 8 |  |  | 5 |  |  | 3 |  |  | N/A
2019 |  |  |  |  |  |  |  |  |  |  |  | 20 |  |  | 10 |  |  | 9 |  |  | 1 |  |  | (7) |  |  | 2 |  |  | N/A
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 269 |  |  | 333 |  |  | 337 |  |  | 326 |  |  | 17 |  |  | N/A
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 314 |  |  | 308 |  |  | 294 |  |  | 13 |  |  | N/A
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 303 |  |  | 295 |  |  | 41 |  |  | N/A
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 267 |  |  | 76 |  |  | N/A
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 1,229 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 14 |  |  | $ | 20 |  |  | $ | 18 |  |  | $ | 19 |  |  | $ | 18 |  |  | $ | 19 |  |  | $ | 19 |  |  | $ | 19 |  |  | $ | 19 |  |  | $ | 19 |  |  |  |  |
2015 |  |  |  | (3) |  |  | (2) |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  | 2 |  |  |  |  |
2016 |  |  |  |  |  | (7) |  |  | 2 |  |  | 2 |  |  | 3 |  |  | 2 |  |  | 3 |  |  | 3 |  |  | 3 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 31 |  |  | 32 |  |  | 37 |  |  | 27 |  |  | 14 |  |  | 16 |  |  | 17 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 27 |  |  | 5 |  |  | 16 |  |  | (13) |  |  | (11) |  |  | (9) |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 4 |  |  | 7 |  |  | 11 |  |  | (14) |  |  | (13) |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 56 |  |  | 158 |  |  | 207 |  |  | 249 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 65 |  |  | 171 |  |  | 222 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 70 |  |  | 169 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 9 |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | 668 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 2 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 563 |  |  |  |  |
Property excluding property catastrophe (in millions)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 142 |  |  | $ | 117 |  |  | $ | 98 |  |  | $ | 90 |  |  | $ | 88 |  |  | $ | 84 |  |  | $ | 82 |  |  | $ | 80 |  |  | $ | 79 |  |  | $ | 79 |  |  | $ | — |  |  | N/A
2015 |  |  |  | 214 |  |  | 188 |  |  | 184 |  |  | 188 |  |  | 187 |  |  | 176 |  |  | 173 |  |  | 167 |  |  | 167 |  |  | 4 |  |  | N/A
2016 |  |  |  |  |  | 175 |  |  | 145 |  |  | 137 |  |  | 135 |  |  | 139 |  |  | 136 |  |  | 130 |  |  | 130 |  |  | 6 |  |  | N/A
2017 |  |  |  |  |  |  |  | 268 |  |  | 250 |  |  | 237 |  |  | 230 |  |  | 214 |  |  | 206 |  |  | 202 |  |  | 7 |  |  | N/A
2018 |  |  |  |  |  |  |  |  |  | 224 |  |  | 239 |  |  | 235 |  |  | 212 |  |  | 202 |  |  | 203 |  |  | 7 |  |  | N/A
2019 |  |  |  |  |  |  |  |  |  |  |  | 216 |  |  | 206 |  |  | 195 |  |  | 190 |  |  | 190 |  |  | 3 |  |  | N/A
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 368 |  |  | 340 |  |  | 320 |  |  | 320 |  |  | 15 |  |  | N/A
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 545 |  |  | 497 |  |  | 491 |  |  | 38 |  |  | N/A
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 742 |  |  | 668 |  |  | 119 |  |  | N/A
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 835 |  |  | 414 |  |  | N/A
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 3,285 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 23 |  |  | $ | 62 |  |  | $ | 71 |  |  | $ | 76 |  |  | $ | 78 |  |  | $ | 78 |  |  | $ | 78 |  |  | $ | 78 |  |  | $ | 78 |  |  | $ | 78 |  |  |  |  |
2015 |  |  |  | 75 |  |  | 119 |  |  | 149 |  |  | 160 |  |  | 165 |  |  | 159 |  |  | 159 |  |  | 159 |  |  | 160 |  |  |  |  |
2016 |  |  |  |  |  | 33 |  |  | 94 |  |  | 98 |  |  | 104 |  |  | 111 |  |  | 114 |  |  | 115 |  |  | 115 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 28 |  |  | 125 |  |  | 156 |  |  | 164 |  |  | 179 |  |  | 182 |  |  | 186 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 30 |  |  | 108 |  |  | 152 |  |  | 167 |  |  | 175 |  |  | 177 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 43 |  |  | 124 |  |  | 150 |  |  | 162 |  |  | 169 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 101 |  |  | 207 |  |  | 243 |  |  | 267 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 136 |  |  | 270 |  |  | 364 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 143 |  |  | 361 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 152 |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | 2,029 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 5 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 1,261 |  |  |  |  |
Marine and aviation (in millions)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 31 |  |  | $ | 29 |  |  | $ | 27 |  |  | $ | 25 |  |  | $ | 23 |  |  | $ | 23 |  |  | $ | 22 |  |  | $ | 22 |  |  | $ | 19 |  |  | $ | 18 |  |  | $ | — |  |  | N/A
2015 |  |  |  | 33 |  |  | 37 |  |  | 32 |  |  | 31 |  |  | 30 |  |  | 28 |  |  | 27 |  |  | 25 |  |  | 24 |  |  | 1 |  |  | N/A
2016 |  |  |  |  |  | 27 |  |  | 23 |  |  | 23 |  |  | 19 |  |  | 17 |  |  | 15 |  |  | 12 |  |  | 11 |  |  | 3 |  |  | N/A
2017 |  |  |  |  |  |  |  | 29 |  |  | 26 |  |  | 24 |  |  | 21 |  |  | 20 |  |  | 17 |  |  | 15 |  |  | 3 |  |  | N/A
2018 |  |  |  |  |  |  |  |  |  | 27 |  |  | 26 |  |  | 24 |  |  | 24 |  |  | 21 |  |  | 21 |  |  | 3 |  |  | N/A
2019 |  |  |  |  |  |  |  |  |  |  |  | 48 |  |  | 55 |  |  | 60 |  |  | 61 |  |  | 62 |  |  | 9 |  |  | N/A
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 83 |  |  | 76 |  |  | 79 |  |  | 80 |  |  | 10 |  |  | N/A
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 110 |  |  | 96 |  |  | 81 |  |  | 18 |  |  | N/A
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 126 |  |  | 138 |  |  | 59 |  |  | N/A
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 161 |  |  | 127 |  |  | N/A
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 611 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 4 |  |  | $ | 8 |  |  | $ | 11 |  |  | $ | 12 |  |  | $ | 15 |  |  | $ | 15 |  |  | $ | 16 |  |  | $ | 16 |  |  | $ | 17 |  |  | $ | 17 |  |  |  |  |
2015 |  |  |  | — |  |  | 13 |  |  | 19 |  |  | 21 |  |  | 22 |  |  | 22 |  |  | 22 |  |  | 22 |  |  | 22 |  |  |  |  |
2016 |  |  |  |  |  | (7) |  |  | (2) |  |  | — |  |  | 3 |  |  | 6 |  |  | 7 |  |  | 7 |  |  | 7 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 2 |  |  | 6 |  |  | 9 |  |  | 11 |  |  | 12 |  |  | 12 |  |  | 12 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 2 |  |  | 7 |  |  | 11 |  |  | 13 |  |  | 14 |  |  | 15 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 11 |  |  | 21 |  |  | 29 |  |  | 35 |  |  | 43 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 9 |  |  | 26 |  |  | 42 |  |  | 60 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8 |  |  | 24 |  |  | 45 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 12 |  |  | 37 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 13 |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | 271 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 17 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 357 |  |  |  |  |
Other specialty (in millions)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of reported claims
|  | Year ended December 31, |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 337 |  |  | $ | 316 |  |  | $ | 318 |  |  | $ | 312 |  |  | $ | 307 |  |  | $ | 308 |  |  | $ | 304 |  |  | $ | 298 |  |  | $ | 296 |  |  | $ | 295 |  |  | $ | 1 |  |  | N/A
2015 |  |  |  | 280 |  |  | 278 |  |  | 276 |  |  | 273 |  |  | 273 |  |  | 270 |  |  | 259 |  |  | 258 |  |  | 255 |  |  | 3 |  |  | N/A
2016 |  |  |  |  |  | 326 |  |  | 323 |  |  | 316 |  |  | 307 |  |  | 314 |  |  | 309 |  |  | 306 |  |  | 307 |  |  | 6 |  |  | N/A
2017 |  |  |  |  |  |  |  | 398 |  |  | 390 |  |  | 372 |  |  | 372 |  |  | 370 |  |  | 366 |  |  | 363 |  |  | 15 |  |  | N/A
2018 |  |  |  |  |  |  |  |  |  | 416 |  |  | 409 |  |  | 404 |  |  | 428 |  |  | 424 |  |  | 423 |  |  | 29 |  |  | N/A
2019 |  |  |  |  |  |  |  |  |  |  |  | 427 |  |  | 406 |  |  | 400 |  |  | 395 |  |  | 405 |  |  | 40 |  |  | N/A
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 593 |  |  | 524 |  |  | 519 |  |  | 539 |  |  | 61 |  |  | N/A
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 610 |  |  | 611 |  |  | 613 |  |  | 80 |  |  | N/A
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 953 |  |  | 935 |  |  | 225 |  |  | N/A
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,348 |  |  | 817 |  |  | N/A
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 5,483 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | $ | 96 |  |  | $ | 186 |  |  | $ | 229 |  |  | $ | 248 |  |  | $ | 258 |  |  | $ | 271 |  |  | $ | 275 |  |  | $ | 278 |  |  | $ | 280 |  |  | $ | 282 |  |  |  |  |
2015 |  |  |  | 83 |  |  | 162 |  |  | 197 |  |  | 211 |  |  | 224 |  |  | 236 |  |  | 239 |  |  | 240 |  |  | 241 |  |  |  |  |
2016 |  |  |  |  |  | 108 |  |  | 205 |  |  | 242 |  |  | 261 |  |  | 277 |  |  | 283 |  |  | 289 |  |  | 293 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 136 |  |  | 256 |  |  | 298 |  |  | 313 |  |  | 326 |  |  | 337 |  |  | 346 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 130 |  |  | 276 |  |  | 315 |  |  | 336 |  |  | 353 |  |  | 376 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 121 |  |  | 211 |  |  | 277 |  |  | 303 |  |  | 325 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 134 |  |  | 293 |  |  | 370 |  |  | 405 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 152 |  |  | 311 |  |  | 432 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 182 |  |  | 464 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 244 |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | 3,408 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 19 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 2,094 |  |  |  |  |
The following table presents the average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance, as of December 31, 2023:
|  | Average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance
|  | Year 1 |  | Year 2 |  | Year 3 |  | Year 4 |  | Year 5 |  | Year 6 |  | Year 7 |  | Year 8 |  | Year 9 |  | Year 10
Casualty |  | 2.8 | % |  | 7.7 | % |  | 12.1 | % |  | 10.4 | % |  | 11.4 | % |  | 8.5 | % |  | 7.8 | % |  | 5.3 | % |  | 5.2 | % |  | 2.9 | %
Property catastrophe |  | 56.0 | % |  | (17.5) | % |  | 47.2 | % |  | (41.9) | % |  | (6.2) | % |  | 10.9 | % |  | 2.4 | % |  | 1.1 | % |  | (1.7) | % |  | — | %
Property excluding property catastrophe |  | 25.0 | % |  | 38.2 | % |  | 14.2 | % |  | 6.0 | % |  | 4.4 | % |  | 0.2 | % |  | 0.7 | % |  | 0.1 | % |  | 0.4 | % |  | 0.4 | %
Marine and aviation |  | 3.0 | % |  | 28.8 | % |  | 20.0 | % |  | 13.0 | % |  | 10.6 | % |  | 3.4 | % |  | 2.2 | % |  | 1.0 | % |  | 3.8 | % |  | 0.4 | %
Other specialty |  | 28.6 | % |  | 29.9 | % |  | 13.9 | % |  | 5.7 | % |  | 4.5 | % |  | 3.9 | % |  | 1.7 | % |  | 0.9 | % |  | 0.6 | % |  | 1.0 | %
Mortgage Segment The Company’s mortgage segment includes (1) U.S. primary mortgage insurance (2) U.S. credit risk transfer and other, and (3) international mortgage insurance and reinsurance. The latter two categories along with second lien and student loan exposures are excluded on the basis of insignificance for the purposes of presenting disclosures related to short duration contracts. For primary mortgage insurance business, the Company establishes case reserves for loans that have been reported as delinquent by loan servicers as well as those that are delinquent but not reported (IBNR reserves). The Company also reserves for the expenses of adjusting claims related to these delinquencies. The trigger that creates a case reserve estimate is that an insured loan is reported to us as being two payments in arrears. The actuarial reviews and documentation created in the reserving process are completed in accordance with generally accepted actuarial standards. The selected assumptions reflect actuarial judgment based on the analysis of historical data and experience combined with information concerning current underwriting, economic, judicial, regulatory and other influences on ultimate claim settlements. Because the reserving process requires the Company to forecast future conditions, it is inherently uncertain and requires significant judgment and estimation. The use of different estimates would result in the establishment of different reserve levels. Additionally, changes in estimates are likely to occur from period to period as economic conditions change, and the ultimate liability may vary significantly from the estimates used. Major risk factors include (but are not limited to) changes in home prices and borrower equity, which can limit the borrower’s ability to sell the property and satisfy the outstanding loan balance, and changes in unemployment, which can affect the borrower’s income and ability to make mortgage payments. The unique nature of the COVID-19 pandemic, with no historical precedent, adds further uncertainty to current reserve estimates. The lead actuarial methodology used by the Company is a frequency-severity method based on the inventory of pending delinquencies. Each month the loan servicers report the delinquency status of each insured loan. Using the frequency-severity method allows the Company to take advantage of its knowledge of the number of delinquent loans and the coverage provided (“risk size”) on those loans by directly relating the reserves to these amounts. The delinquencies are grouped into homogeneous cohorts for analysis, reflecting the age of delinquency. A claim rate is then developed for each cohort which represents the frequency with which the delinquencies become claims. The claim frequency rates are based on an analysis of the patterns of emerging cure counts and claim counts, the foreclosure status of the pending delinquencies, the product and geographical mix of the delinquencies and our view of future economic and claim conditions, which include trends in home prices and unemployment. Claim rates can vary materially by age of delinquency, depending on the mix of delinquencies and economic conditions. Claim size severity estimates are determined by examining the risk sizes on the delinquent loans and estimating the portion of risk that will be paid, as well as any expenses. This is done based on a review of historical development patterns, an assessment of economic conditions and the level of equity the borrowers may have in their homes, as well as considering economic conditions and loss mitigation opportunities. Mortgage insurance is generally not subject to large claim sizes, as with some other lines of insurance. A claim size over $250,000 is rare, and this helps reduce the volatility of claim size estimates. The claim rate and claim size assumptions generate case reserves for the population of reported delinquencies. The reserve for unreported delinquencies (included in IBNR reserves) is estimated by looking at historical patterns of reporting. Claim rates and claim sizes can then be assigned to estimated unreported delinquencies using assumptions made in the establishment of case reserves. Mortgage insurance Loss Reserves are short-tail, in the sense that the vast majority of delinquencies are resolved within two years of being reported. Due to the forbearances and foreclosure moratoriums associated with COVID-19, settlement timelines have been extended. While reserves are initially analyzed by reserve cohort, as described above, they are also rolled up by underwriting year to ensure that reserve assumptions are consistent with the performance of the underwriting year. The accuracy of prior reserve assumptions is also checked in hindsight to determine if adjustments to the assumptions are needed. Loss Reserves for the Company’s mortgage reinsurance business and GSE credit risk sharing transactions are comprised of case reserves and IBNR reserves. The Company’s mortgage reinsurance operations receive reports of delinquent loans and claims notices from ceding companies and record case reserves based upon the amount of reserves recommended by the ceding company. In addition, specific claim and delinquency information reported by ceding companies is used in the process of estimating IBNR reserves. The following table presents information on the mortgage segment’s short-duration insurance contracts:
U.S. primary mortgage insurance (in millions except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance |  | December 31, 2023
|  |  |  |  |  |  | Total of IBNR liabilities plus expected development on reported claims |  | Cumulative number of paid claims
Year ended December 31, |  |  |  |  |  |  |
Accident year |  | 2014 unaudited |  | 2015 unaudited |  | 2016 unaudited |  | 2017 unaudited |  | 2018 unaudited |  | 2019 unaudited |  | 2020 unaudited |  | 2021 unaudited |  |  | 2022 unaudited |  | 2023 |  |
2014 |  | $ | 316 |  |  | $ | 297 |  |  | $ | 279 |  |  | $ | 266 |  |  | $ | 266 |  |  | $ | 261 |  |  | $ | 263 |  |  | $ | 263 |  |  |  | $ | 261 |  |  | $ | 259 |  |  | — |  |  | 6,332 |
2015 |  |  |  | 223 |  |  | 197 |  |  | 198 |  |  | 195 |  |  | 189 |  |  | 191 |  |  | 191 |  |  |  | 189 |  |  | 188 |  |  | — |  |  | 4,588 |
2016 |  |  |  |  |  | 184 |  |  | 171 |  |  | 149 |  |  | 141 |  |  | 142 |  |  | 142 |  |  |  | 137 |  |  | 136 |  |  | — |  |  | 3,462 |
2017 |  |  |  |  |  |  |  | 179 |  |  | 132 |  |  | 107 |  |  | 108 |  |  | 109 |  |  |  | 102 |  |  | 99 |  |  | — |  |  | 2,541 |
2018 |  |  |  |  |  |  |  |  |  | 132 |  |  | 96 |  |  | 89 |  |  | 88 |  |  |  | 72 |  |  | 69 |  |  | — |  |  | 1,763 |
2019 |  |  |  |  |  |  |  |  |  |  |  | 108 |  |  | 119 |  |  | 110 |  |  |  | 63 |  |  | 51 |  |  | — |  |  | 1,149 |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 420 |  |  | 374 |  |  |  | 78 |  |  | 33 |  |  | — |  |  | 492 |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 144 |  |  |  | 77 |  |  | 20 |  |  | — |  |  | 211 |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 173 |  |  | 55 |  |  | — |  |  | 135 |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 182 |  |  | 1 |  |  | 9 |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | $ | 1,092 |  |  |  |  |
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance |  |  |  |
2014 |  | 20 |  |  | 129 |  |  | 202 |  |  | 234 |  |  | 247 |  |  | 254 |  |  | 256 |  |  | 257 |  |  |  | 257 |  |  | 258 |  |  |  |  |
2015 |  |  |  | 16 |  |  | 92 |  |  | 151 |  |  | 171 |  |  | 180 |  |  | 183 |  |  | 184 |  |  |  | 185 |  |  | 186 |  |  |  |  |
2016 |  |  |  |  |  | 11 |  |  | 72 |  |  | 113 |  |  | 127 |  |  | 131 |  |  | 132 |  |  |  | 132 |  |  | 133 |  |  |  |  |
2017 |  |  |  |  |  |  |  | 9 |  |  | 48 |  |  | 79 |  |  | 87 |  |  | 90 |  |  |  | 92 |  |  | 93 |  |  |  |  |
2018 |  |  |  |  |  |  |  |  |  | 4 |  |  | 31 |  |  | 50 |  |  | 56 |  |  |  | 59 |  |  | 60 |  |  |  |  |
2019 |  |  |  |  |  |  |  |  |  |  |  | 3 |  |  | 20 |  |  | 29 |  |  |  | 34 |  |  | 39 |  |  |  |  |
2020 |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |  | 4 |  |  |  | 8 |  |  | 13 |  |  |  |  |
2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | — |  |  |  | 2 |  |  | 5 |  |  |  |  |
2022 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | — |  |  | 3 |  |  |  |  |
2023 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | — |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Total |  | 790 |  |  |  |  |
|  |  |  |  |  |  |  |  |  | All outstanding liabilities before 2014, net of reinsurance |  | 8 |  |  |  |  |
|  |  |  |  |  |  |  | Liabilities for losses and loss adjustment expenses, net of reinsurance |  | $ | 310 |  |  |  |  |
The following table presents the average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance, as of December 31, 2023:
Average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance |  |  |  |  |  |
|  | Year 1 |  | Year 2 |  | Year 3 |  | Year 4 |  | Year 5 |  | Year 6 |  | Year 7 |  | Year 8 |  | Year 9 |  | Year 10
U.S. Primary |  | 5.1 | % |  | 29.1 | % |  | 24.2 | % |  | 10.7 | % |  | 4.7 | % |  | 1.8 | % |  | 0.7 | % |  | 0.5 | % |  | 0.2 | % |  | 0.1 | %
The following table represents a reconciliation of the disclosures of net incurred and paid loss development tables to the reserve for losses and loss adjustment expenses at December 31, 2023:
| December 31, 2023
Net outstanding liabilities |
Insurance |
Property, energy, marine and aviation | $ | 824 |
Third party occurrence business | 3,601 |
Third party claims-made business | 2,352 |
Multi-line and other specialty | 1,348 |
Reinsurance |
Casualty | 2,706 |
Property catastrophe | 563 |
Property excluding property catastrophe | 1,261 |
Marine and aviation | 357 |
Other specialty | 2,094 |
Mortgage |
U.S. primary | 310 |
Other short duration lines not included in disclosures | 284 |
Total for short duration lines | 15,700 |
Unpaid losses and loss adjustment expenses recoverable |
Insurance |
Property, energy, marine and aviation | 359 |
Third party occurrence business | 2,025 |
Third party claims-made business | 1,001 |
Multi-line and other specialty | 246 |
Reinsurance |
Casualty | 738 |
Property catastrophe | 519 |
Property excluding property catastrophe | 239 |
Marine and aviation | 240 |
Other specialty | 828 |
Mortgage |
U.S. primary | 33 |
Other short duration lines not included in disclosures (1) | 468 |
Intercompany eliminations | (6) |
Total for short duration lines | 6,690 |
Lines other than short duration | 132 |
Discounting | (66) |
Unallocated claims adjustment expenses | 296 |
| 362 |
Reserve for losses and loss adjustment expenses | $ | 22,752 |
(1) Includes unpaid loss and loss adjustment expenses recoverable of $225 million related to the loss portfolio transfer reinsurance agreements.

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- Definition The entire disclosure for insurance products considered to be short-duration contracts because the contract provides insurance protection for a fixed period of short duration and enables the insurer to cancel the contract or to adjust the provisions of the contract at the end of any contract period, such as adjusting the amount of premiums charged or coverage provided, and on contracts on which amounts are paid but insurance risk is not transferred. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 944 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org//944/tableOfContent + Details
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