Insurance Liabilities - Undiscounted, Incurred and Paid Losses and Allocated Loss Adjustment Expenses (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) claim	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	$ 254
Prior Year Development Net of External Reinsurance After ADC Cessions	(120)
U.S. Workers' Compensation (before discount)
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	7,083
2024 Prior Year Development Excluding the Impact of ADC	(273)
Incurred Impact of ADC	(3,954)
2024 (Net of Impact of ADC)	6,766
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	3,806
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	4,145
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	7,422
Prior Year Development Net of External Reinsurance After ADC Cessions	(205)
Paid Impact of ADC	$ (71)
Year 1 (as a percent)	11.90%
Year 2 (as a percent)	17.50%
Year 3 (as a percent)	11.00%
Year 4 (as a percent)	7.50%
Year 5 (as a percent)	4.50%
Year 6 (as a percent)	3.30%
Year 7 (as a percent)	2.70%
Year 8 (as a percent)	1.20%
Year 9 (as a percent)	1.40%
Year 10 (as a percent)	1.50%
U.S. Workers' Compensation (before discount) | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 71
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(3,708)
Unallocated loss adjustment expense prior year development	(214)
Prior Year Development Net of External Reinsurance After ADC Cessions	68
U.S. Workers' Compensation (before discount) | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,464	$ 1,592	$ 1,612	$ 1,634	$ 1,675	$ 1,722	$ 1,814	$ 1,866	$ 1,864	$ 1,708
2024 Prior Year Development Excluding the Impact of ADC	(128)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 179
Cumulative Number of Reported Claims | claim	37,763
Incurred Impact of ADC	$ (317)
IBNR Impact of ADC	(144)
2024 (Net of Impact of ADC)	1,147	1,154	1,092	1,041	1,105	1,134	1,318	1,279	1,279
Total of IBNR Liabilities Net of Impact of ADC	35
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,080	1,058	1,038	1,013	979	925	854	725	524	234
Prior Year Development Net of External Reinsurance After ADC Cessions	(7)
Paid Impact of ADC	(71)
U.S. Workers' Compensation (before discount) | 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(317)	(438)	(520)	(593)	(570)	(588)	(496)	(587)	(585)
Prior Year Development Net of External Reinsurance After ADC Cessions	121
U.S. Workers' Compensation (before discount) | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	986	1,025	1,036	1,075	1,090	1,140	1,318	1,346	1,299
2024 Prior Year Development Excluding the Impact of ADC	(39)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 178
Cumulative Number of Reported Claims | claim	32,178
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	986	1,025	1,036	1,075	1,090	1,140	1,318	1,346	1,299
Total of IBNR Liabilities Net of Impact of ADC	178
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	708	694	686	662	630	584	521	378	147
Prior Year Development Net of External Reinsurance After ADC Cessions	(39)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2016 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	673	705	712	731	763	776	850	789
2024 Prior Year Development Excluding the Impact of ADC	(32)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 176
Cumulative Number of Reported Claims | claim	28,057
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	673	705	712	731	763	776	850	789
Total of IBNR Liabilities Net of Impact of ADC	176
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	402	395	389	367	333	294	224	93
Prior Year Development Net of External Reinsurance After ADC Cessions	(32)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2017 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	786	875	896	911	961	1,021	998
2024 Prior Year Development Excluding the Impact of ADC	(89)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 200
Cumulative Number of Reported Claims | claim	22,484
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	786	875	896	911	961	1,021	998
Total of IBNR Liabilities Net of Impact of ADC	200
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	448	409	388	359	296	215	85
Prior Year Development Net of External Reinsurance After ADC Cessions	(89)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2018 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	730	788	801	812	873	887
2024 Prior Year Development Excluding the Impact of ADC	(58)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 218
Cumulative Number of Reported Claims | claim	17,292
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	730	788	801	812	873	887
Total of IBNR Liabilities Net of Impact of ADC	218
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	417	389	347	301	219	93
Prior Year Development Net of External Reinsurance After ADC Cessions	(58)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2019 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	434	477	521	573	597
2024 Prior Year Development Excluding the Impact of ADC	(43)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 104
Cumulative Number of Reported Claims | claim	14,124
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	434	477	521	573	597
Total of IBNR Liabilities Net of Impact of ADC	104
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	259	245	205	159	64
Prior Year Development Net of External Reinsurance After ADC Cessions	(43)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2020 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	514	545	570	597
2024 Prior Year Development Excluding the Impact of ADC	(31)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 212
Cumulative Number of Reported Claims | claim	11,293
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	514	545	570	597
Total of IBNR Liabilities Net of Impact of ADC	212
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	211	171	128	60
Prior Year Development Net of External Reinsurance After ADC Cessions	(31)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2021 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	464	493	523
2024 Prior Year Development Excluding the Impact of ADC	(29)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 209
Cumulative Number of Reported Claims | claim	9,829
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	464	493	523
Total of IBNR Liabilities Net of Impact of ADC	209
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	143	102	45
Prior Year Development Net of External Reinsurance After ADC Cessions	(29)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2022 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	465	500
2024 Prior Year Development Excluding the Impact of ADC	(35)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 273
Cumulative Number of Reported Claims | claim	8,954
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	465	500
Total of IBNR Liabilities Net of Impact of ADC	273
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	103	38
Prior Year Development Net of External Reinsurance After ADC Cessions	(35)
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2023 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	567
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 455
Cumulative Number of Reported Claims | claim	6,285
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	567
Total of IBNR Liabilities Net of Impact of ADC	455
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	35
Prior Year Development Net of External Reinsurance After ADC Cessions
Paid Impact of ADC	0
U.S. Workers' Compensation (before discount) | 2024 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Workers' Compensation (before discount) | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	(484)
Incurred Impact of ADC	(317)
2024 (Net of Impact of ADC)	6,766	6,562	6,151	5,740	5,389	4,958	4,484	3,414	2,578
Prior Year Development Net of External Reinsurance After ADC Cessions	(363)
U.S. Workers' Compensation (before discount) | Short Duration Insurance Contracts Last Ten Accident Years | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(317)	(438)	(520)	(593)	(570)	(588)	(496)	(587)	(585)
Prior Year Development Net of External Reinsurance After ADC Cessions	121
U.S. Workers' Compensation (before discount) | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
U.S. Workers' Compensation (before discount) | Incurred Impact Of Adverse Development Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	71
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(3,708)
U.S. Workers' Compensation (before discount) | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(187)
Prior Year Development Net of External Reinsurance After ADC Cessions	(26)
U.S. Workers' Compensation (before discount) | Short Duration Insurance Contracts Accident Years Prior To 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior Year Development Net of External Reinsurance After ADC Cessions	161
U.S. Workers' Compensation (before discount) | Net Of Impact Of Adverse Development Reinsurance Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	3,735
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	437
Unallocated loss adjustment expense prior year development	184
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	3,468
U.S. Workers' Compensation (before discount) | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	398
U.S. Excess Casualty
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	7,409
2024 Prior Year Development Excluding the Impact of ADC	545
Incurred Impact of ADC	(1,955)
2024 (Net of Impact of ADC)	6,875
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	4,350
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	2,104
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	5,163
Prior Year Development Net of External Reinsurance After ADC Cessions	238
Paid Impact of ADC	$ (197)
Year 1 (as a percent)	1.10%
Year 2 (as a percent)	10.10%
Year 3 (as a percent)	8.90%
Year 4 (as a percent)	19.50%
Year 5 (as a percent)	10.80%
Year 6 (as a percent)	7.20%
Year 7 (as a percent)	6.10%
Year 8 (as a percent)	7.90%
Year 9 (as a percent)	3.10%
Year 10 (as a percent)	2.00%
U.S. Excess Casualty | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 197
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(1,618)
Unallocated loss adjustment expense prior year development	(57)
Prior Year Development Net of External Reinsurance After ADC Cessions	(307)
U.S. Excess Casualty | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,723	1,658	1,686	1,721	1,694	1,656	1,603	1,440	1,463	989
2024 Prior Year Development Excluding the Impact of ADC	65
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 258
Cumulative Number of Reported Claims | claim	3,269
Incurred Impact of ADC	$ (534)
IBNR Impact of ADC	(131)
2024 (Net of Impact of ADC)	1,189	1,196	1,174	1,231	1,211	1,163	1,139	1,015	1,027
Total of IBNR Liabilities Net of Impact of ADC	127
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,325	1,291	1,253	1,124	1,061	935	718	391	210	9
Prior Year Development Net of External Reinsurance After ADC Cessions	(7)
Paid Impact of ADC	(197)
U.S. Excess Casualty | 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(534)	(462)	(512)	(490)	(483)	(493)	(464)	(425)	(436)
Prior Year Development Net of External Reinsurance After ADC Cessions	(72)
U.S. Excess Casualty | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,317	1,276	1,263	1,250	1,274	1,171	1,162	1,146	898
2024 Prior Year Development Excluding the Impact of ADC	41
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 343
Cumulative Number of Reported Claims | claim	2,970
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,317	1,276	1,263	1,250	1,274	1,171	1,162	1,146	898
Total of IBNR Liabilities Net of Impact of ADC	343
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	851	798	670	566	502	388	204	80	28
Prior Year Development Net of External Reinsurance After ADC Cessions	41
Paid Impact of ADC	0
U.S. Excess Casualty | 2016 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,228	1,182	1,200	1,157	1,153	1,097	1,002	856
2024 Prior Year Development Excluding the Impact of ADC	46
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 227
Cumulative Number of Reported Claims | claim	2,252
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,228	1,182	1,200	1,157	1,153	1,097	1,002	856
Total of IBNR Liabilities Net of Impact of ADC	227
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	860	781	676	585	505	156	45	1
Prior Year Development Net of External Reinsurance After ADC Cessions	46
Paid Impact of ADC	0
U.S. Excess Casualty | 2017 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	779	779	769	769	721	646	648
2024 Prior Year Development Excluding the Impact of ADC	0
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 149
Cumulative Number of Reported Claims | claim	1,613
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	779	779	769	769	721	646	648
Total of IBNR Liabilities Net of Impact of ADC	149
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	527	494	414	315	227	125	1
Prior Year Development Net of External Reinsurance After ADC Cessions	0
Paid Impact of ADC	0
U.S. Excess Casualty | 2018 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	604	600	612	597	583	577
2024 Prior Year Development Excluding the Impact of ADC	4
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 279
Cumulative Number of Reported Claims | claim	1,469
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	604	600	612	597	583	577
Total of IBNR Liabilities Net of Impact of ADC	279
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	253	216	157	79	43	7
Prior Year Development Net of External Reinsurance After ADC Cessions	4
Paid Impact of ADC	0
U.S. Excess Casualty | 2019 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	404	420	410	413	406
2024 Prior Year Development Excluding the Impact of ADC	(16)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 194
Cumulative Number of Reported Claims | claim	1,438
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	404	420	410	413	406
Total of IBNR Liabilities Net of Impact of ADC	194
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	188	128	33	15	4
Prior Year Development Net of External Reinsurance After ADC Cessions	(16)
Paid Impact of ADC	0
U.S. Excess Casualty | 2020 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	358	274	277	278
2024 Prior Year Development Excluding the Impact of ADC	84
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 154
Cumulative Number of Reported Claims | claim	1,039
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	358	274	277	278
Total of IBNR Liabilities Net of Impact of ADC	154
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	161	62	43	4
Prior Year Development Net of External Reinsurance After ADC Cessions	84
Paid Impact of ADC	0
U.S. Excess Casualty | 2021 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	333	305	305
2024 Prior Year Development Excluding the Impact of ADC	28
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 156
Cumulative Number of Reported Claims | claim	690
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	333	305	305
Total of IBNR Liabilities Net of Impact of ADC	156
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	96	51	14
Prior Year Development Net of External Reinsurance After ADC Cessions	28
Paid Impact of ADC	0
U.S. Excess Casualty | 2022 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	348	345
2024 Prior Year Development Excluding the Impact of ADC	3
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 210
Cumulative Number of Reported Claims | claim	567
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	348	345
Total of IBNR Liabilities Net of Impact of ADC	210
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	89	1
Prior Year Development Net of External Reinsurance After ADC Cessions	3
Paid Impact of ADC	0
U.S. Excess Casualty | 2023 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	315
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 302
Cumulative Number of Reported Claims | claim	235
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	315
Total of IBNR Liabilities Net of Impact of ADC	302
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
Prior Year Development Net of External Reinsurance After ADC Cessions
Paid Impact of ADC	0
U.S. Excess Casualty | 2024 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Excess Casualty | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	255
Incurred Impact of ADC	(534)
2024 (Net of Impact of ADC)	6,875	6,377	6,010	5,695	5,348	4,654	3,951	3,017	1,925
Prior Year Development Net of External Reinsurance After ADC Cessions	183
U.S. Excess Casualty | Short Duration Insurance Contracts Last Ten Accident Years | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(534)	(462)	(512)	(490)	(483)	(493)	(464)	(425)	(436)
Prior Year Development Net of External Reinsurance After ADC Cessions	(72)
U.S. Excess Casualty | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
U.S. Excess Casualty | Incurred Impact Of Adverse Development Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	197
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(1,618)
U.S. Excess Casualty | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	217
Prior Year Development Net of External Reinsurance After ADC Cessions	39
U.S. Excess Casualty | Short Duration Insurance Contracts Accident Years Prior To 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior Year Development Net of External Reinsurance After ADC Cessions	(178)
U.S. Excess Casualty | Net Of Impact Of Adverse Development Reinsurance Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	(4,153)
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	486
Unallocated loss adjustment expense prior year development	16
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	3,208
U.S. Excess Casualty | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	73
U.S. Other Casualty
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	9,520
2024 Prior Year Development Excluding the Impact of ADC	12
Incurred Impact of ADC	(998)
2024 (Net of Impact of ADC)	9,247
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	5,435
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	1,300
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	5,385
Prior Year Development Net of External Reinsurance After ADC Cessions	44
Paid Impact of ADC	$ (194)
Year 1 (as a percent)	5.20%
Year 2 (as a percent)	9.70%
Year 3 (as a percent)	13.80%
Year 4 (as a percent)	14.00%
Year 5 (as a percent)	13.30%
Year 6 (as a percent)	8.70%
Year 7 (as a percent)	7.80%
Year 8 (as a percent)	4.00%
Year 9 (as a percent)	3.50%
Year 10 (as a percent)	0.60%
U.S. Other Casualty | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 194
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(919)
Unallocated loss adjustment expense prior year development	(28)
Prior Year Development Net of External Reinsurance After ADC Cessions	32
U.S. Other Casualty | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,770	1,796	1,815	1,824	1,834	1,794	1,736	1,829	1,762	1,329
2024 Prior Year Development Excluding the Impact of ADC	(26)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 6
Cumulative Number of Reported Claims | claim	35,881
Incurred Impact of ADC	$ (273)
IBNR Impact of ADC	(3)
2024 (Net of Impact of ADC)	1,497	1,514	1,563	1,562	1,553	1,493	1,423	1,373	1,361
Total of IBNR Liabilities Net of Impact of ADC	3
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,717	1,707	1,680	1,603	1,485	1,351	1,087	769	309	105
Prior Year Development Net of External Reinsurance After ADC Cessions	(17)
Paid Impact of ADC	(194)
U.S. Other Casualty | 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(273)	(282)	(252)	(262)	(281)	(301)	(313)	(456)	(401)
Prior Year Development Net of External Reinsurance After ADC Cessions	9
U.S. Other Casualty | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,264	1,297	1,293	1,323	1,340	1,391	1,321	1,343	1,339
2024 Prior Year Development Excluding the Impact of ADC	(33)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 69
Cumulative Number of Reported Claims | claim	29,391
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,264	1,297	1,293	1,323	1,340	1,391	1,321	1,343	1,339
Total of IBNR Liabilities Net of Impact of ADC	69
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,144	1,074	1,018	938	846	703	489	298	77
Prior Year Development Net of External Reinsurance After ADC Cessions	(33)
Paid Impact of ADC	0
U.S. Other Casualty | 2016 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	662	654	643	668	674	738	629	602
2024 Prior Year Development Excluding the Impact of ADC	8
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 14
Cumulative Number of Reported Claims | claim	21,382
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	662	654	643	668	674	738	629	602
Total of IBNR Liabilities Net of Impact of ADC	14
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	613	592	527	455	314	216	111	51
Prior Year Development Net of External Reinsurance After ADC Cessions	8
Paid Impact of ADC	0
U.S. Other Casualty | 2017 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	841	810	824	870	837	845	802
2024 Prior Year Development Excluding the Impact of ADC	31
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 154
Cumulative Number of Reported Claims | claim	17,096
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	841	810	824	870	837	845	802
Total of IBNR Liabilities Net of Impact of ADC	154
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	636	565	470	360	227	122	43
Prior Year Development Net of External Reinsurance After ADC Cessions	31
Paid Impact of ADC	0
U.S. Other Casualty | 2018 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,024	1,039	1,062	1,053	1,058	1,059
2024 Prior Year Development Excluding the Impact of ADC	(15)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 469
Cumulative Number of Reported Claims | claim	21,383
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,024	1,039	1,062	1,053	1,058	1,059
Total of IBNR Liabilities Net of Impact of ADC	469
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	474	410	321	226	138	53
Prior Year Development Net of External Reinsurance After ADC Cessions	(15)
Paid Impact of ADC	0
U.S. Other Casualty | 2019 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	519	540	538	576	524
2024 Prior Year Development Excluding the Impact of ADC	(21)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 223
Cumulative Number of Reported Claims | claim	11,622
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	519	540	538	576	524
Total of IBNR Liabilities Net of Impact of ADC	223
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	252	198	139	73	26
Prior Year Development Net of External Reinsurance After ADC Cessions	(21)
Paid Impact of ADC	0
U.S. Other Casualty | 2020 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	818	790	793	795
2024 Prior Year Development Excluding the Impact of ADC	28
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 470
Cumulative Number of Reported Claims | claim	11,249
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	818	790	793	795
Total of IBNR Liabilities Net of Impact of ADC	470
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	265	169	87	32
Prior Year Development Net of External Reinsurance After ADC Cessions	28
Paid Impact of ADC	0
U.S. Other Casualty | 2021 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	827	819	793
2024 Prior Year Development Excluding the Impact of ADC	8
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 530
Cumulative Number of Reported Claims | claim	13,636
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	827	819	793
Total of IBNR Liabilities Net of Impact of ADC	530
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	195	112	38
Prior Year Development Net of External Reinsurance After ADC Cessions	8
Paid Impact of ADC	0
U.S. Other Casualty | 2022 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	955	933
2024 Prior Year Development Excluding the Impact of ADC	22
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 781
Cumulative Number of Reported Claims | claim	13,687
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	955	933
Total of IBNR Liabilities Net of Impact of ADC	781
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	102	36
Prior Year Development Net of External Reinsurance After ADC Cessions	22
Paid Impact of ADC	0
U.S. Other Casualty | 2023 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	840
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 754
Cumulative Number of Reported Claims | claim	9,070
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	840
Total of IBNR Liabilities Net of Impact of ADC	754
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	37
Prior Year Development Net of External Reinsurance After ADC Cessions
Paid Impact of ADC	0
U.S. Other Casualty | 2024 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Other Casualty | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	2
Incurred Impact of ADC	(273)
2024 (Net of Impact of ADC)	9,247	8,396	7,509	6,847	5,986	5,526	4,175	3,318	2,700
Prior Year Development Net of External Reinsurance After ADC Cessions	11
U.S. Other Casualty | Short Duration Insurance Contracts Last Ten Accident Years | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(273)	(282)	(252)	(262)	(281)	(301)	(313)	(456)	(401)
Prior Year Development Net of External Reinsurance After ADC Cessions	9
U.S. Other Casualty | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
U.S. Other Casualty | Incurred Impact Of Adverse Development Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	194
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(919)
U.S. Other Casualty | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(14)
Prior Year Development Net of External Reinsurance After ADC Cessions	37
U.S. Other Casualty | Short Duration Insurance Contracts Accident Years Prior To 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior Year Development Net of External Reinsurance After ADC Cessions	51
U.S. Other Casualty | Net Of Impact Of Adverse Development Reinsurance Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	(5,241)
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	381
Unallocated loss adjustment expense prior year development	(4)
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	4,387
U.S. Other Casualty | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	24
U.S. Financial Lines
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	16,431
2024 Prior Year Development Excluding the Impact of ADC	51
Incurred Impact of ADC	(514)
2024 (Net of Impact of ADC)	15,946
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	10,922
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	427
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	5,936
Prior Year Development Net of External Reinsurance After ADC Cessions	(40)
Paid Impact of ADC	$ (367)
Year 1 (as a percent)	3.90%
Year 2 (as a percent)	14.00%
Year 3 (as a percent)	16.00%
Year 4 (as a percent)	15.00%
Year 5 (as a percent)	12.30%
Year 6 (as a percent)	8.50%
Year 7 (as a percent)	6.90%
Year 8 (as a percent)	6.20%
Year 9 (as a percent)	4.00%
Year 10 (as a percent)	0.70%
U.S. Financial Lines | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 367
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(396)
Unallocated loss adjustment expense prior year development	(13)
Prior Year Development Net of External Reinsurance After ADC Cessions	(91)
U.S. Financial Lines | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,039	2,048	2,044	1,959	1,874	1,830	1,788	1,743	1,762	1,737
2024 Prior Year Development Excluding the Impact of ADC	(9)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 63
Cumulative Number of Reported Claims | claim	16,263
Incurred Impact of ADC	$ (485)
IBNR Impact of ADC	(50)
2024 (Net of Impact of ADC)	1,554	1,553	1,605	1,595	1,550	1,552	1,462	1,430	1,429
Total of IBNR Liabilities Net of Impact of ADC	13
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,929	1,914	1,818	1,686	1,488	1,282	1,055	791	390	63
Prior Year Development Net of External Reinsurance After ADC Cessions	1
Paid Impact of ADC	(367)
U.S. Financial Lines | 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(485)	(495)	(439)	(364)	(324)	(278)	(326)	(313)	(333)
Prior Year Development Net of External Reinsurance After ADC Cessions	10
U.S. Financial Lines | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,322	2,308	2,325	2,281	2,139	2,064	1,993	1,855	1,605
2024 Prior Year Development Excluding the Impact of ADC	14
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 112
Cumulative Number of Reported Claims | claim	16,138
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	2,322	2,308	2,325	2,281	2,139	2,064	1,993	1,855	1,605
Total of IBNR Liabilities Net of Impact of ADC	112
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	2,115	2,039	1,903	1,826	1,659	1,358	1,002	499	73
Prior Year Development Net of External Reinsurance After ADC Cessions	14
Paid Impact of ADC	0
U.S. Financial Lines | 2016 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,969	1,957	1,987	1,898	1,846	1,756	1,675	1,564
2024 Prior Year Development Excluding the Impact of ADC	12
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 121
Cumulative Number of Reported Claims | claim	15,287
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,969	1,957	1,987	1,898	1,846	1,756	1,675	1,564
Total of IBNR Liabilities Net of Impact of ADC	121
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,777	1,653	1,515	1,396	1,118	761	391	64
Prior Year Development Net of External Reinsurance After ADC Cessions	12
Paid Impact of ADC	0
U.S. Financial Lines | 2017 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,282	2,322	2,225	2,063	1,882	1,766	1,640
2024 Prior Year Development Excluding the Impact of ADC	(40)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 354
Cumulative Number of Reported Claims | claim	14,857
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	2,282	2,322	2,225	2,063	1,882	1,766	1,640
Total of IBNR Liabilities Net of Impact of ADC	354
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,776	1,601	1,415	1,126	835	486	86
Prior Year Development Net of External Reinsurance After ADC Cessions	(40)
Paid Impact of ADC	0
U.S. Financial Lines | 2018 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,945	1,912	1,926	1,627	1,536	1,503
2024 Prior Year Development Excluding the Impact of ADC	33
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 358
Cumulative Number of Reported Claims | claim	13,381
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,945	1,912	1,926	1,627	1,536	1,503
Total of IBNR Liabilities Net of Impact of ADC	358
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,423	1,204	953	642	367	94
Prior Year Development Net of External Reinsurance After ADC Cessions	33
Paid Impact of ADC	0
U.S. Financial Lines | 2019 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,470	1,457	1,408	1,252	1,213
2024 Prior Year Development Excluding the Impact of ADC	13
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 260
Cumulative Number of Reported Claims | claim	10,461
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,470	1,457	1,408	1,252	1,213
Total of IBNR Liabilities Net of Impact of ADC	260
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,063	915	648	356	84
Prior Year Development Net of External Reinsurance After ADC Cessions	13
Paid Impact of ADC	0
U.S. Financial Lines | 2020 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,316	1,388	1,408	1,430
2024 Prior Year Development Excluding the Impact of ADC	(72)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 700
Cumulative Number of Reported Claims | claim	7,226
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,316	1,388	1,408	1,430
Total of IBNR Liabilities Net of Impact of ADC	700
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	468	315	151	43
Prior Year Development Net of External Reinsurance After ADC Cessions	(72)
Paid Impact of ADC	0
U.S. Financial Lines | 2021 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,105	1,108	1,130
2024 Prior Year Development Excluding the Impact of ADC	(3)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 857
Cumulative Number of Reported Claims | claim	5,939
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,105	1,108	1,130
Total of IBNR Liabilities Net of Impact of ADC	857
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	177	109	30
Prior Year Development Net of External Reinsurance After ADC Cessions	(3)
Paid Impact of ADC	0
U.S. Financial Lines | 2022 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,041	1,043
2024 Prior Year Development Excluding the Impact of ADC	(2)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 800
Cumulative Number of Reported Claims | claim	6,997
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,041	1,043
Total of IBNR Liabilities Net of Impact of ADC	800
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	150	46
Prior Year Development Net of External Reinsurance After ADC Cessions	(2)
Paid Impact of ADC	0
U.S. Financial Lines | 2023 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	942
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 851
Cumulative Number of Reported Claims | claim	7,258
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	942
Total of IBNR Liabilities Net of Impact of ADC	851
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	44
Prior Year Development Net of External Reinsurance After ADC Cessions
Paid Impact of ADC	0
U.S. Financial Lines | 2024 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Financial Lines | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	(54)
Incurred Impact of ADC	(485)
2024 (Net of Impact of ADC)	15,946	15,048	14,014	12,146	10,166	8,641	6,770	4,849	3,034
Prior Year Development Net of External Reinsurance After ADC Cessions	(44)
U.S. Financial Lines | Short Duration Insurance Contracts Last Ten Accident Years | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(485)	(495)	(439)	(364)	(324)	(278)	(326)	(313)	(333)
Prior Year Development Net of External Reinsurance After ADC Cessions	10
U.S. Financial Lines | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
U.S. Financial Lines | Incurred Impact Of Adverse Development Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	367
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(396)
U.S. Financial Lines | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	92
Prior Year Development Net of External Reinsurance After ADC Cessions	4
U.S. Financial Lines | Short Duration Insurance Contracts Accident Years Prior To 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior Year Development Net of External Reinsurance After ADC Cessions	(88)
U.S. Financial Lines | Net Of Impact Of Adverse Development Reinsurance Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	(10,555)
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	31
Unallocated loss adjustment expense prior year development	0
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	5,422
U.S. Financial Lines | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	13
U.S. Property and Special Risks
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	27,783
2024 Prior Year Development Excluding the Impact of ADC	(44)
Incurred Impact of ADC	(179)
2024 (Net of Impact of ADC)	27,686
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	23,702
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	395
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	4,476
Prior Year Development Net of External Reinsurance After ADC Cessions	4
Paid Impact of ADC	$ (70)
Year 1 (as a percent)	35.60%
Year 2 (as a percent)	31.10%
Year 3 (as a percent)	10.90%
Year 4 (as a percent)	7.10%
Year 5 (as a percent)	5.10%
Year 6 (as a percent)	2.80%
Year 7 (as a percent)	2.20%
Year 8 (as a percent)	1.60%
Year 9 (as a percent)	1.90%
Year 10 (as a percent)	0.20%
U.S. Property and Special Risks | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 70
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(152)
Unallocated loss adjustment expense prior year development	(1)
Prior Year Development Net of External Reinsurance After ADC Cessions	48
U.S. Property and Special Risks | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,484	2,493	2,490	2,479	2,471	2,466	2,492	2,489	2,506	2,567
2024 Prior Year Development Excluding the Impact of ADC	(9)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 4
Cumulative Number of Reported Claims | claim	59,598
Incurred Impact of ADC	$ (97)
IBNR Impact of ADC	(3)
2024 (Net of Impact of ADC)	2,387	2,393	2,375	2,372	2,372	2,372	2,405	2,391	2,365
Total of IBNR Liabilities Net of Impact of ADC	1
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	2,462	2,457	2,391	2,344	2,308	2,240	2,121	1,878	1,572	844
Prior Year Development Net of External Reinsurance After ADC Cessions	(6)
Paid Impact of ADC	(70)
U.S. Property and Special Risks | 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(97)	(100)	(115)	(107)	(99)	(94)	(87)	(98)	(141)
Prior Year Development Net of External Reinsurance After ADC Cessions	3
U.S. Property and Special Risks | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,727	2,713	2,700	2,694	2,707	2,697	2,690	2,748	2,674
2024 Prior Year Development Excluding the Impact of ADC	14
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 8
Cumulative Number of Reported Claims | claim	54,893
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	2,727	2,713	2,700	2,694	2,707	2,697	2,690	2,748	2,674
Total of IBNR Liabilities Net of Impact of ADC	8
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	2,679	2,647	2,616	2,539	2,464	2,296	2,076	1,747	821
Prior Year Development Net of External Reinsurance After ADC Cessions	14
Paid Impact of ADC	0
U.S. Property and Special Risks | 2016 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	4,187	4,175	4,212	4,173	4,153	4,127	4,239	4,569
2024 Prior Year Development Excluding the Impact of ADC	12
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 12
Cumulative Number of Reported Claims | claim	79,846
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	4,187	4,175	4,212	4,173	4,153	4,127	4,239	4,569
Total of IBNR Liabilities Net of Impact of ADC	12
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	4,129	4,055	3,999	3,897	3,638	3,281	2,625	1,137
Prior Year Development Net of External Reinsurance After ADC Cessions	12
Paid Impact of ADC	0
U.S. Property and Special Risks | 2017 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	3,204	3,210	3,201	3,229	2,992	2,993	2,978
2024 Prior Year Development Excluding the Impact of ADC	(6)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 49
Cumulative Number of Reported Claims | claim	70,122
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	3,204	3,210	3,201	3,229	2,992	2,993	2,978
Total of IBNR Liabilities Net of Impact of ADC	49
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	3,094	2,994	2,863	2,715	2,509	2,162	977
Prior Year Development Net of External Reinsurance After ADC Cessions	(6)
Paid Impact of ADC	0
U.S. Property and Special Risks | 2018 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,198	2,177	2,222	2,211	2,146	2,177
2024 Prior Year Development Excluding the Impact of ADC	21
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 34
Cumulative Number of Reported Claims | claim	78,995
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	2,198	2,177	2,222	2,211	2,146	2,177
Total of IBNR Liabilities Net of Impact of ADC	34
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	2,124	2,083	2,037	1,906	1,673	1,039
Prior Year Development Net of External Reinsurance After ADC Cessions	21
Paid Impact of ADC	0
U.S. Property and Special Risks | 2019 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	3,269	3,238	3,280	3,320	3,391
2024 Prior Year Development Excluding the Impact of ADC	31
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 645
Cumulative Number of Reported Claims | claim	68,891
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	3,269	3,238	3,280	3,320	3,391
Total of IBNR Liabilities Net of Impact of ADC	645
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	2,414	2,190	1,874	1,613	844
Prior Year Development Net of External Reinsurance After ADC Cessions	31
Paid Impact of ADC	0
U.S. Property and Special Risks | 2020 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,190	2,160	2,213	2,339
2024 Prior Year Development Excluding the Impact of ADC	30
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 122
Cumulative Number of Reported Claims | claim	82,226
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	2,190	2,160	2,213	2,339
Total of IBNR Liabilities Net of Impact of ADC	122
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	2,004	1,983	1,743	878
Prior Year Development Net of External Reinsurance After ADC Cessions	30
Paid Impact of ADC	0
U.S. Property and Special Risks | 2021 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	3,240	3,281	3,171
2024 Prior Year Development Excluding the Impact of ADC	(41)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 504
Cumulative Number of Reported Claims | claim	86,499
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	3,240	3,281	3,171
Total of IBNR Liabilities Net of Impact of ADC	504
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	2,437	2,207	1,208
Prior Year Development Net of External Reinsurance After ADC Cessions	(41)
Paid Impact of ADC	0
U.S. Property and Special Risks | 2022 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,440	2,528
2024 Prior Year Development Excluding the Impact of ADC	(88)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 431
Cumulative Number of Reported Claims | claim	99,114
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	2,440	2,528
Total of IBNR Liabilities Net of Impact of ADC	431
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,692	1,173
Prior Year Development Net of External Reinsurance After ADC Cessions	(88)
Paid Impact of ADC	0
U.S. Property and Special Risks | 2023 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,844
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 537
Cumulative Number of Reported Claims | claim	25,410
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,844
Total of IBNR Liabilities Net of Impact of ADC	537
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	667
Prior Year Development Net of External Reinsurance After ADC Cessions
Paid Impact of ADC	0
U.S. Property and Special Risks | 2024 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Property and Special Risks | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	(36)
Incurred Impact of ADC	(97)
2024 (Net of Impact of ADC)	27,686	25,875	23,374	20,338	17,761	14,366	12,312	9,708	5,039
Prior Year Development Net of External Reinsurance After ADC Cessions	(33)
U.S. Property and Special Risks | Short Duration Insurance Contracts Last Ten Accident Years | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(97)	(100)	(115)	(107)	(99)	(94)	(87)	(98)	(141)
Prior Year Development Net of External Reinsurance After ADC Cessions	3
U.S. Property and Special Risks | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
U.S. Property and Special Risks | Incurred Impact Of Adverse Development Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	70
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(152)
U.S. Property and Special Risks | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(8)
Prior Year Development Net of External Reinsurance After ADC Cessions	38
U.S. Property and Special Risks | Short Duration Insurance Contracts Accident Years Prior To 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior Year Development Net of External Reinsurance After ADC Cessions	46
U.S. Property and Special Risks | Net Of Impact Of Adverse Development Reinsurance Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	(23,632)
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	243
Unallocated loss adjustment expense prior year development	(1)
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	4,297
U.S. Property and Special Risks | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	0
U.S. Personal Insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	11,863
2024 Prior Year Development Excluding the Impact of ADC	(23)
Incurred Impact of ADC	0
2024 (Net of Impact of ADC)	11,854
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	10,979
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(48)
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	836
Prior Year Development Net of External Reinsurance After ADC Cessions	(25)
Paid Impact of ADC	$ (9)
Year 1 (as a percent)	60.30%
Year 2 (as a percent)	22.90%
Year 3 (as a percent)	4.70%
Year 4 (as a percent)	0.50%
Year 5 (as a percent)	2.50%
Year 6 (as a percent)	1.00%
Year 7 (as a percent)	0.70%
Year 8 (as a percent)	0.50%
Year 9 (as a percent)	0.10%
Year 10 (as a percent)	0.20%
U.S. Personal Insurance | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 9
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	0
Unallocated loss adjustment expense prior year development	0
Prior Year Development Net of External Reinsurance After ADC Cessions	(2)
U.S. Personal Insurance | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,488	1,487	1,488	1,487	1,485	1,482	1,483	1,494	1,498	1,511
2024 Prior Year Development Excluding the Impact of ADC	1
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 12
Cumulative Number of Reported Claims | claim	261,309
Incurred Impact of ADC	$ (9)
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,479	1,479	1,481	1,482	1,480	1,476	1,472	1,475	1,476
Total of IBNR Liabilities Net of Impact of ADC	12
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,474	1,471	1,468	1,463	1,461	1,455	1,439	1,411	1,320	931
Prior Year Development Net of External Reinsurance After ADC Cessions	0
Paid Impact of ADC	(9)
U.S. Personal Insurance | 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(9)	(8)	(7)	(5)	(5)	(6)	(11)	(19)	(22)
Prior Year Development Net of External Reinsurance After ADC Cessions	(1)
U.S. Personal Insurance | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,541	1,541	1,544	1,544	1,542	1,540	1,533	1,533	1,536
2024 Prior Year Development Excluding the Impact of ADC	0
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 16
Cumulative Number of Reported Claims | claim	247,696
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,541	1,541	1,544	1,544	1,542	1,540	1,533	1,533	1,536
Total of IBNR Liabilities Net of Impact of ADC	16
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,521	1,521	1,518	1,512	1,501	1,460	1,422	1,344	857
Prior Year Development Net of External Reinsurance After ADC Cessions	0
Paid Impact of ADC	0
U.S. Personal Insurance | 2016 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,899	1,896	1,916	1,924	2,057	2,011	2,137	1,878
2024 Prior Year Development Excluding the Impact of ADC	3
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 15
Cumulative Number of Reported Claims | claim	220,270
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,899	1,896	1,916	1,924	2,057	2,011	2,137	1,878
Total of IBNR Liabilities Net of Impact of ADC	15
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,878	1,861	1,852	1,826	1,789	1,896	1,672	941
Prior Year Development Net of External Reinsurance After ADC Cessions	3
Paid Impact of ADC	0
U.S. Personal Insurance | 2017 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,927	1,920	1,936	1,937	2,154	2,193	2,188
2024 Prior Year Development Excluding the Impact of ADC	7
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 37
Cumulative Number of Reported Claims | claim	102,483
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,927	1,920	1,936	1,937	2,154	2,193	2,188
Total of IBNR Liabilities Net of Impact of ADC	37
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,881	1,849	1,832	1,789	1,973	1,939	1,227
Prior Year Development Net of External Reinsurance After ADC Cessions	7
Paid Impact of ADC	0
U.S. Personal Insurance | 2018 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,569	1,578	1,596	1,646	1,664	1,593
2024 Prior Year Development Excluding the Impact of ADC	(9)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 44
Cumulative Number of Reported Claims | claim	93,909
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	1,569	1,578	1,596	1,646	1,664	1,593
Total of IBNR Liabilities Net of Impact of ADC	44
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	1,516	1,491	1,416	1,379	1,295	884
Prior Year Development Net of External Reinsurance After ADC Cessions	(9)
Paid Impact of ADC	0
U.S. Personal Insurance | 2019 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	890	894	913	906	954
2024 Prior Year Development Excluding the Impact of ADC	(4)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 33
Cumulative Number of Reported Claims | claim	55,713
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	890	894	913	906	954
Total of IBNR Liabilities Net of Impact of ADC	33
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	846	824	725	679	667
Prior Year Development Net of External Reinsurance After ADC Cessions	(4)
Paid Impact of ADC	0
U.S. Personal Insurance | 2020 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	752	762	765	748
2024 Prior Year Development Excluding the Impact of ADC	(10)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 73
Cumulative Number of Reported Claims | claim	57,288
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	752	762	765	748
Total of IBNR Liabilities Net of Impact of ADC	73
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	662	658	650	488
Prior Year Development Net of External Reinsurance After ADC Cessions	(10)
Paid Impact of ADC	0
U.S. Personal Insurance | 2021 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	525	529	517
2024 Prior Year Development Excluding the Impact of ADC	(4)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 100
Cumulative Number of Reported Claims | claim	55,394
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	525	529	517
Total of IBNR Liabilities Net of Impact of ADC	100
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	406	401	372
Prior Year Development Net of External Reinsurance After ADC Cessions	(4)
Paid Impact of ADC	0
U.S. Personal Insurance | 2022 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	668	677
2024 Prior Year Development Excluding the Impact of ADC	(9)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 122
Cumulative Number of Reported Claims | claim	47,201
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	668	677
Total of IBNR Liabilities Net of Impact of ADC	122
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	522	400
Prior Year Development Net of External Reinsurance After ADC Cessions	(9)
Paid Impact of ADC	0
U.S. Personal Insurance | 2023 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	604
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 294
Cumulative Number of Reported Claims | claim	29,007
Incurred Impact of ADC	$ 0
IBNR Impact of ADC	0
2024 (Net of Impact of ADC)	604
Total of IBNR Liabilities Net of Impact of ADC	294
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	273
Prior Year Development Net of External Reinsurance After ADC Cessions
Paid Impact of ADC	0
U.S. Personal Insurance | 2024 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	0
Prior Year Development Net of External Reinsurance After ADC Cessions	0
U.S. Personal Insurance | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	(25)
Incurred Impact of ADC	(9)
2024 (Net of Impact of ADC)	11,854	11,276	10,668	10,187	9,851	8,813	7,330	4,886	3,012
Prior Year Development Net of External Reinsurance After ADC Cessions	(26)
U.S. Personal Insurance | Short Duration Insurance Contracts Last Ten Accident Years | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred Impact of ADC	(9)	(8)	(7)	(5)	(5)	(6)	(11)	(19)	(22)
Prior Year Development Net of External Reinsurance After ADC Cessions	(1)
U.S. Personal Insurance | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
U.S. Personal Insurance | Incurred Impact Of Adverse Development Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	9
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	0
U.S. Personal Insurance | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	3
Prior Year Development Net of External Reinsurance After ADC Cessions	2
U.S. Personal Insurance | Short Duration Insurance Contracts Accident Years Prior To 2015 | Adverse Development Reinsurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior Year Development Net of External Reinsurance After ADC Cessions	(1)
U.S. Personal Insurance | Net Of Impact Of Adverse Development Reinsurance Cover
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	(10,970)
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(48)
Unallocated loss adjustment expense prior year development	(1)
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	836
U.S. Personal Insurance | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	(1)
UK/Europe Casualty and Financial lines
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	13,266
2024 Prior Year Development Excluding the Impact of ADC	170
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	6,843
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	857
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	7,280
Prior Year Development Net of External Reinsurance After ADC Cessions	$ 170
Year 1 (as a percent)	5.40%
Year 2 (as a percent)	13.60%
Year 3 (as a percent)	11.50%
Year 4 (as a percent)	10.80%
Year 5 (as a percent)	8.90%
Year 6 (as a percent)	10.70%
Year 7 (as a percent)	5.80%
Year 8 (as a percent)	5.30%
Year 9 (as a percent)	3.20%
Year 10 (as a percent)	1.60%
UK/Europe Casualty and Financial lines | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	$ 1,215	1,221	1,210	1,191	1,184	1,265	1,187	1,166	1,177	1,043
2024 Prior Year Development Excluding the Impact of ADC	(6)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 63
Cumulative Number of Reported Claims | claim	113,532
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,023	1,004	955	914	828	656	546	416	230	69
UK/Europe Casualty and Financial lines | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,618	1,547	1,548	1,536	1,539	1,426	1,421	1,342	1,251
2024 Prior Year Development Excluding the Impact of ADC	71
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 143
Cumulative Number of Reported Claims | claim	142,423
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,253	1,214	1,127	1,022	896	746	563	363	115
UK/Europe Casualty and Financial lines | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,398	1,351	1,311	1,323	1,263	1,151	1,221	1,282
2024 Prior Year Development Excluding the Impact of ADC	47
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 171
Cumulative Number of Reported Claims | claim	149,728
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,025	924	862	724	578	428	269	93
UK/Europe Casualty and Financial lines | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,686	1,596	1,554	1,455	1,416	1,316	1,286
2024 Prior Year Development Excluding the Impact of ADC	90
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 229
Cumulative Number of Reported Claims | claim	151,718
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,172	1,085	867	711	549	359	109
UK/Europe Casualty and Financial lines | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,307	1,282	1,291	1,276	1,204	1,189
2024 Prior Year Development Excluding the Impact of ADC	25
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 210
Cumulative Number of Reported Claims | claim	142,854
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 842	728	632	458	297	95
UK/Europe Casualty and Financial lines | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,114	1,154	1,161	1,215	1,163
2024 Prior Year Development Excluding the Impact of ADC	(40)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 353
Cumulative Number of Reported Claims | claim	86,254
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 572	484	351	218	57
UK/Europe Casualty and Financial lines | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,261	1,279	1,275	1,316
2024 Prior Year Development Excluding the Impact of ADC	(18)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 566
Cumulative Number of Reported Claims | claim	77,499
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 434	331	224	49
UK/Europe Casualty and Financial lines | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,197	1,203	1,243
2024 Prior Year Development Excluding the Impact of ADC	(6)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 681
Cumulative Number of Reported Claims | claim	74,390
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 282	177	55
UK/Europe Casualty and Financial lines | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,230	1,233
2024 Prior Year Development Excluding the Impact of ADC	(3)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 803
Cumulative Number of Reported Claims | claim	69,733
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 183	35
UK/Europe Casualty and Financial lines | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,240
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 1,052
Cumulative Number of Reported Claims | claim	60,687
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 57
UK/Europe Casualty and Financial lines | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	160
UK/Europe Casualty and Financial lines | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
UK/Europe Casualty and Financial lines | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	10
UK/Europe Casualty and Financial lines | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	0
UK/Europe Property and Special Risks
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	12,444
2024 Prior Year Development Excluding the Impact of ADC	(35)
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	10,174
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	85
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	2,355
Prior Year Development Net of External Reinsurance After ADC Cessions	$ (35)
Year 1 (as a percent)	20.90%
Year 2 (as a percent)	37.50%
Year 3 (as a percent)	18.70%
Year 4 (as a percent)	8.20%
Year 5 (as a percent)	3.70%
Year 6 (as a percent)	2.20%
Year 7 (as a percent)	1.10%
Year 8 (as a percent)	(0.004)
Year 9 (as a percent)	1.60%
Year 10 (as a percent)	0.30%
UK/Europe Property and Special Risks | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	$ 1,399	1,407	1,421	1,388	1,400	1,410	1,431	1,457	1,472	1,516
2024 Prior Year Development Excluding the Impact of ADC	(8)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 3
Cumulative Number of Reported Claims | claim	54,684
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,377	1,373	1,331	1,329	1,321	1,298	1,263	1,163	895	336
UK/Europe Property and Special Risks | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,553	1,558	1,563	1,626	1,632	1,635	1,661	1,636	1,494
2024 Prior Year Development Excluding the Impact of ADC	(5)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 17
Cumulative Number of Reported Claims | claim	57,353
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,522	1,520	1,546	1,528	1,501	1,457	1,327	1,080	441
UK/Europe Property and Special Risks | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,535	1,533	1,533	1,567	1,582	1,576	1,598	1,609
2024 Prior Year Development Excluding the Impact of ADC	2
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 15
Cumulative Number of Reported Claims | claim	53,528
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,446	1,439	1,426	1,388	1,333	1,193	916	345
UK/Europe Property and Special Risks | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,422	1,427	1,429	1,481	1,493	1,514	1,547
2024 Prior Year Development Excluding the Impact of ADC	(5)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 25
Cumulative Number of Reported Claims | claim	44,342
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,325	1,301	1,267	1,254	1,131	952	308
UK/Europe Property and Special Risks | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,065	1,062	1,064	1,076	1,073	1,112
2024 Prior Year Development Excluding the Impact of ADC	3
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 45
Cumulative Number of Reported Claims | claim	33,930
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 953	922	884	798	632	258
UK/Europe Property and Special Risks | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,190	1,200	1,181	1,223	1,282
2024 Prior Year Development Excluding the Impact of ADC	(10)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 94
Cumulative Number of Reported Claims | claim	26,280
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,004	896	805	657	245
UK/Europe Property and Special Risks | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	923	914	958	995
2024 Prior Year Development Excluding the Impact of ADC	9
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 85
Cumulative Number of Reported Claims | claim	22,968
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 748	672	489	185
UK/Europe Property and Special Risks | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,238	1,253	1,098
2024 Prior Year Development Excluding the Impact of ADC	(15)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 95
Cumulative Number of Reported Claims | claim	24,972
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,100	650	190
UK/Europe Property and Special Risks | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,038	1,034
2024 Prior Year Development Excluding the Impact of ADC	4
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 179
Cumulative Number of Reported Claims | claim	23,267
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 504	150
UK/Europe Property and Special Risks | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,081
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 542
Cumulative Number of Reported Claims | claim	17,451
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 195
UK/Europe Property and Special Risks | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	(25)
UK/Europe Property and Special Risks | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
UK/Europe Property and Special Risks | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	(10)
UK/Europe Property and Special Risks | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	0
UK/Europe and Japan Personal Insurance
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	18,091
2024 Prior Year Development Excluding the Impact of ADC	(47)
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	16,861
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	39
Liabilities for losses and loss adjustment expenses and prior year loss development, net of reinsurance	1,269
Prior Year Development Net of External Reinsurance After ADC Cessions	$ (47)
Year 1 (as a percent)	58.50%
Year 2 (as a percent)	25.80%
Year 3 (as a percent)	7.00%
Year 4 (as a percent)	3.50%
Year 5 (as a percent)	1.80%
Year 6 (as a percent)	1.30%
Year 7 (as a percent)	0.60%
Year 8 (as a percent)	0.40%
Year 9 (as a percent)	0.30%
Year 10 (as a percent)	0.20%
UK/Europe and Japan Personal Insurance | 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	$ 2,128	2,127	2,123	2,126	2,126	2,126	2,127	2,135	2,134	2,153
2024 Prior Year Development Excluding the Impact of ADC	1
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 2
Cumulative Number of Reported Claims | claim	1,777,959
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 2,117	2,112	2,104	2,096	2,079	2,055	2,020	1,927	1,751	$ 1,155
UK/Europe and Japan Personal Insurance | 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,084	2,086	2,082	2,090	2,092	2,094	2,099	2,112	2,113
2024 Prior Year Development Excluding the Impact of ADC	(2)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 3
Cumulative Number of Reported Claims | claim	1,795,415
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 2,070	2,065	2,057	2,043	2,019	1,976	1,894	1,723	$ 1,154
UK/Europe and Japan Personal Insurance | 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,989	1,990	1,960	1,995	1,978	1,982	1,995	2,070
2024 Prior Year Development Excluding the Impact of ADC	(1)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 4
Cumulative Number of Reported Claims | claim	1,719,018
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,960	1,949	1,949	1,930	1,896	1,830	1,682	$ 1,130
UK/Europe and Japan Personal Insurance | 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	2,272	2,274	2,296	2,251	2,279	2,283	2,372
2024 Prior Year Development Excluding the Impact of ADC	(2)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 1
Cumulative Number of Reported Claims | claim	1,917,173
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 2,250	2,226	2,180	2,139	2,062	1,913	$ 1,426
UK/Europe and Japan Personal Insurance | 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,827	1,825	1,853	1,834	1,871	1,915
2024 Prior Year Development Excluding the Impact of ADC	2
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ (1)
Cumulative Number of Reported Claims | claim	1,676,687
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,798	1,777	1,746	1,690	1,576	$ 1,120
UK/Europe and Japan Personal Insurance | 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,552	1,563	1,580	1,627	1,757
2024 Prior Year Development Excluding the Impact of ADC	(11)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 5
Cumulative Number of Reported Claims | claim	1,392,905
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,513	1,485	1,446	1,350	$ 937
UK/Europe and Japan Personal Insurance | 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,555	1,555	1,554	1,626
2024 Prior Year Development Excluding the Impact of ADC	0
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 13
Cumulative Number of Reported Claims | claim	1,394,112
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,465	1,408	1,306	$ 920
UK/Europe and Japan Personal Insurance | 2022
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,716	1,752	1,710
2024 Prior Year Development Excluding the Impact of ADC	(36)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 67
Cumulative Number of Reported Claims | claim	2,072,754
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,550	1,440	$ 1,006
UK/Europe and Japan Personal Insurance | 2023
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,552	1,557
2024 Prior Year Development Excluding the Impact of ADC	(5)
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 101
Cumulative Number of Reported Claims | claim	1,435,789
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 1,290	$ 881
UK/Europe and Japan Personal Insurance | 2024
Liability for Claims and Claims Adjustment Expense [Line Items]
Incurred losses and allocated loss adjustment expenses, undiscounted and net of reinsurance	1,416
2024 Prior Year Development Excluding the Impact of ADC
Total of IBNR Liabilities Plus Expected Development on Reported Losses	$ 177
Cumulative Number of Reported Claims | claim	1,260,923
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	$ 848
UK/Europe and Japan Personal Insurance | Short Duration Insurance Contracts Last Ten Accident Years
Liability for Claims and Claims Adjustment Expense [Line Items]
2024 Prior Year Development Excluding the Impact of ADC	(54)
UK/Europe and Japan Personal Insurance | Short Duration Insurance Contracts Accident Years Prior To Current Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance from the table below	0
UK/Europe and Japan Personal Insurance | Short Duration Insurance Contracts Accident Years Prior To 2015
Liability for Claims and Claims Adjustment Expense [Line Items]
Liabilities for losses and loss adjustment expenses and prior year development before accident year 2015, net of reinsurance	7
UK/Europe and Japan Personal Insurance | Unallocated To Accident Year
Liability for Claims and Claims Adjustment Expense [Line Items]
Unallocated loss adjustment expense prior year development	$ 0