Unpaid losses and loss expenses (Tables)

12 Months Ended

Dec. 31, 2022

Liability for Claims and Claims Adjustment Expense [Abstract]

Schedule Of Unpaid Losses And Loss Expenses Roll Forward

Chubb establishes reserves for the estimated unpaid ultimate liability for losses and loss expenses under the terms of its policies and agreements. Reserves include estimates for both claims that have been reported and for IBNR claims, and include estimates of expenses associated with processing and settling these claims. Reserves are recorded in Unpaid losses and loss expenses in the Consolidated balance sheets. While we believe that our reserves for unpaid losses and loss expenses at December 31, 2022, are adequate, new information or trends may lead to future developments in incurred loss and loss expenses significantly greater or less than the reserves provided. Any such revisions could result in future changes in estimates of losses or reinsurance recoverable and would be reflected in our results of operations in the period in which the estimates are changed.

The following table presents a reconciliation of beginning and ending Unpaid losses and loss expenses:

	Year Ended December 31
(in millions of U.S. dollars)	2022		2021		2020
Gross unpaid losses and loss expenses, beginning of year	$	72,943	$	67,811	$	62,690
Reinsurance recoverable on unpaid losses (1)	(16,184)		(14,647)		(14,181)
Net unpaid losses and loss expenses, beginning of year	56,759		53,164		48,509
Net losses and loss expenses incurred in respect of losses occurring in:
Current year	24,495		22,966		22,124
Prior years (2)	(1,153)		(986)		(414)
Total	23,342		21,980		21,710
Net losses and loss expenses paid in respect of losses occurring in:
Current year	8,117		7,836		7,782
Prior years	12,206		10,048		9,652
Total	20,323		17,884		17,434
Foreign currency revaluation and other	(583)		(501)		379
Net unpaid losses and loss expenses, end of year	59,195		56,759		53,164
Reinsurance recoverable on unpaid losses (1)	17,128		16,184		14,647
Gross unpaid losses and loss expenses, end of year	$	76,323	$	72,943	$	67,811

(1)     Net of valuation allowance for uncollectible reinsurance.

(2)    Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments, and earned premiums totaling $277 million, $60 million, and $19 million for 2022, 2021, and 2020, respectively.

Reconciliation of Claims Development to Liability [Table Text Block]

The following table presents a reconciliation of the loss development tables to the liability for unpaid losses and loss expenses in the consolidated balance sheet:

Reconciliation of Reserve Balances to Liability for Unpaid Loss and Loss Expenses
(in millions of U.S. dollars)	December 31, 2022
Presented in the loss development tables:
North America Commercial P&C Insurance — Workers' Compensation	$	9,962
North America Commercial P&C Insurance — Liability	20,014
North America Commercial P&C Insurance — Other Casualty	2,530
North America Commercial P&C Insurance — Non-Casualty	3,253
North America Personal P&C Insurance	3,225
Overseas General Insurance — Casualty	7,287
Overseas General Insurance — Non-Casualty	3,206
Global Reinsurance — Casualty	1,208
Global Reinsurance — Non-Casualty	494
Excluded from the loss development tables:
Other	5,210
Net unpaid loss and allocated loss adjustment expense	56,389
Ceded unpaid loss and allocated loss adjustment expense:
North America Commercial P&C Insurance — Workers' Compensation	1,274
North America Commercial P&C Insurance — Liability	6,920
North America Commercial P&C Insurance — Other Casualty	888
North America Commercial P&C Insurance — Non-Casualty	1,883
North America Personal P&C Insurance	530
Overseas General Insurance — Casualty	2,481
Overseas General Insurance — Non-Casualty	1,702
Global Reinsurance — Casualty	55
Global Reinsurance — Non-Casualty	171
Other	1,410
Ceded unpaid loss and allocated loss adjustment expense	17,314
Unpaid loss and loss expense on other than short-duration contracts (1)	943
Unpaid unallocated loss adjustment expenses	1,677
Unpaid losses and loss expenses	$	76,323

(1)     Primarily includes the claims reserve of our International A&H business and Life Insurance segment reserves.

Claims Development tables [Table Text Block]

North America Commercial P&C Insurance — Workers' Compensation — Long-tail

This product line has a broad mix of exposures across industries as well as a mix of policy coverages. Types of coverage include risk management business predominantly with high deductible policies, loss sensitive business (i.e., retrospectively-rated policies), business fronted for captives, as well as excess and primary guaranteed cost coverages.

The triangle below shows all loss and allocated expense development for the workers' compensation product line. In our prior period development disclosure, we exclude any loss development where there is a directly related premium adjustment. For workers' compensation, changes in the exposure base due to payroll audits will drive changes in ultimate losses. In addition, we record involuntary pool assumptions (premiums and losses) on a lagged basis. Both of these items will influence the development in the triangle, particularly the first prior accident year, and are included in the reconciliation table presented on page F-60.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	1,109	$	1,108		$	1,122	$	1,127	$	1,086	$	1,073	$	1,037	$	1,014	$	989	$	968	$	219	43
2014			1,207			1,201		1,217		1,215		1,163		1,100		1,073		1,037		1,007		264		45
2015						1,282		1,259		1,276		1,279		1,217		1,154		1,128		1,092		338		50
2016								1,366		1,361		1,383		1,378		1,269		1,206		1,177		380		52
2017										1,412		1,380		1,399		1,393		1,376		1,176		465		50
2018												1,359		1,361		1,380		1,385		1,384		631		51
2019														1,391		1,384		1,400		1,409		656		48
2020																1,367		1,388		1,409		852		31
2021																		1,348		1,330		780		37
2022																				1,344		988		32
Total																				$	12,296

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	107	$	286		$	422	$	506	$	553	$	587	$	616	$	633	$	650	$	664
2014			113			295		410		484		532		566		599		617		634
2015						116		301		418		501		564		606		628		645
2016								122		326		452		529		584		621		653
2017										120		313		437		516		564		601
2018												130		329		451		528		597
2019														143		341		467		575
2020																111		282		390
2021																		120		331
2022																				131
Total																				$	5,221

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	2,887
Accident years 2013 - 2022 from tables above	7,075
All Accident years	$	9,962

North America Commercial P&C Insurance — Liability — Long-tail

This line consists of primary and excess general liability exposures, medical liability, and professional lines, including directors and officers (D&O) liability, errors and omissions (E&O) liability, employment practices liability (EPL), fidelity bonds, and fiduciary liability.

The primary and excess general liability business represents the largest part of these exposures. The former includes both monoline and commercial package liability. The latter includes a substantial proportion of commercial umbrella, excess and high excess business, where loss activity can produce significant volatility in the loss triangles at later ages within an accident year (and sometimes across years) due to the size of the limits afforded and the complex nature of the underlying losses.

This line includes management and professional liability products provided to a wide variety of clients, from national accounts to small firms along with private and not-for-profit organizations, distributed through brokers, agents, wholesalers, and MGAs. Many of these coverages, particularly D&O and E&O, are typically written on a claims-made form. While most of the coverages are underwritten on a primary basis, there are significant amounts of excess exposure with large policy limits.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	3,540	$	3,534		$	3,534	$	3,524	$	3,422	$	3,208	$	3,115	$	2,958	$	2,950	$	2,997	$	247	25
2014			3,528			3,578		3,667		3,710		3,648		3,463		3,340		3,192		3,142		278		24
2015						3,552		3,701		3,810		3,966		3,934		3,727		3,700		3,569		390		27
2016								3,526		3,587		3,684		3,797		3,792		3,764		3,755		589		27
2017										3,315		3,491		3,573		3,623		3,545		3,434		758		26
2018												3,367		3,485		3,688		3,820		3,900		1,041		28
2019														3,445		3,620		3,858		4,050		1,488		30
2020																4,102		3,826		3,919		2,184		24
2021																		4,315		4,349		3,263		24
2022																				4,561		4,176		24
Total																				$	37,676

North America Commercial P&C Insurance — Liability — Long-tail (continued)
Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	129	$	546		$	1,189	$	1,593	$	2,003	$	2,228	$	2,369	$	2,460	$	2,520	$	2,609
2014			164			678		1,248		1,801		2,199		2,439		2,580		2,669		2,753
2015						138		604		1,203		1,852		2,287		2,527		2,743		2,921
2016								171		662		1,334		1,973		2,331		2,593		2,820
2017										161		616		1,160		1,698		2,000		2,322
2018												189		753		1,301		1,773		2,335
2019														175		669		1,245		1,888
2020																152		589		1,147
2021																		174		608
2022																				144
Total																				$	19,547

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	1,885
Accident years 2013 - 2022 from tables above	18,129
All Accident years	$	20,014

This product line consists of the remaining commercial casualty coverages such as automobile liability and aviation as well as our foreign casualty exposures (mainly auto, general liability and employer responsibility coverages) on U.S.-based multinational accounts. The paid and reported data are impacted by some catastrophe loss activity.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	525	$	530		$	521	$	514	$	468	$	461	$	461	$	457	$	459	$	458	$	8	17
2014			594			582		580		595		554		537		538		530		526		6		17
2015						486		469		500		514		457		454		462		457		23		15
2016								503		501		527		523		480		479		469		27		16
2017										531		565		576		616		604		590		36		17
2018												535		563		574		579		575		25		17
2019														605		636		685		743		143		17
2020																640		633		656		265		11
2021																		675		709		379		12
2022																				782		611		11
Total																				$	5,965

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	68	$	196		$	270	$	348	$	384	$	410	$	418	$	425	$	438	$	441
2014			80			220		317		391		454		472		500		508		513
2015						47		137		214		304		370		394		411		423
2016								52		145		246		323		374		398		424
2017										66		175		312		381		446		496
2018												74		169		270		365		472
2019														70		189		318		465
2020																54		156		273
2021																		60		176
2022																				82
Total																				$	3,765

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	330
Accident years 2013 - 2022 from tables above	2,200
All Accident years	$	2,530

This product line represents first party commercial product lines that are short-tailed in nature, such as property, inland marine, ocean marine, surety, and A&H. There is a wide diversity of products, primary and excess coverages, and policy sizes. During this ten-year period, this product line was impacted by natural catastrophes mainly in the 2017 and 2018 accident years, and in accident year 2020 by direct COVID.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	1,427	$	1,417		$	1,330	$	1,352	$	1,333	$	1,333	$	1,330	$	1,337	$	1,336	$	1,340	$	3	455
2014			1,639			1,655		1,573		1,552		1,543		1,544		1,552		1,545		1,544		2		483
2015						1,730		1,740		1,645		1,633		1,600		1,585		1,587		1,592		1		545
2016								1,904		1,884		1,794		1,775		1,811		1,824		1,820		26		650
2017										2,699		2,602		2,501		2,517		2,509		2,519		65		764
2018												2,047		2,234		2,169		2,161		2,170		35		903
2019														2,046		2,031		1,953		1,944		52		1,043
2020																3,139		2,942		2,726		105		1,124
2021																		2,941		2,824		368		857
2022																				3,048		1,467		751
Total																				$	21,527

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	647	$	1,132		$	1,231	$	1,278	$	1,304	$	1,318	$	1,326	$	1,328	$	1,329	$	1,338
2014			816			1,368		1,478		1,499		1,525		1,540		1,547		1,552		1,552
2015						724		1,339		1,484		1,552		1,567		1,570		1,583		1,582
2016								844		1,499		1,650		1,726		1,754		1,779		1,790
2017										977		2,083		2,299		2,389		2,403		2,427
2018												1,025		1,820		2,012		2,068		2,113
2019														1,028		1,672		1,800		1,856
2020																1,390		2,260		2,466
2021																		1,085		2,100
2022																				1,050
Total																				$	18,274

North America Commercial P&C Insurance — Non-Casualty — Short-tail (continued)
Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	—
Accident years 2013 - 2022 from tables above	3,253
All Accident years	$	3,253

North America Personal P&C Insurance — Short-tail

Chubb provides personal lines coverages for high-net-worth individuals and families in North America including homeowners, automobile, valuable articles (including fine art), umbrella liability, and recreational marine insurance offered through independent regional agents and brokers. During this ten-year period, this segment was also impacted by natural catastrophes, mainly in the 2017 and 2018 accident years.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	1,848	$	1,876		$	1,884	$	1,888	$	1,912	$	1,924	$	1,932	$	1,935	$	1,936	$	1,933	$	18	132
2014			2,198			2,199		2,185		2,139		2,153		2,140		2,134		2,134		2,133		9		144
2015						2,487		2,542		2,553		2,536		2,556		2,562		2,559		2,561		12		148
2016								2,433		2,529		2,538		2,476		2,464		2,457		2,465		17		154
2017										3,027		3,062		2,995		2,991		2,991		3,000		16		163
2018												3,001		3,029		3,095		3,110		3,131		93		170
2019														2,948		2,985		2,986		2,978		116		156
2020																2,922		2,627		2,626		206		123
2021																		3,027		2,877		245		129
2022																				3,102		1,217		94
Total																				$	26,806

North America Personal P&C Insurance — Short-tail (continued)
Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	1,036	$	1,494		$	1,676	$	1,775	$	1,831	$	1,873	$	1,884	$	1,906	$	1,904	$	1,910
2014			1,306			1,759		1,919		2,028		2,073		2,100		2,109		2,116		2,119
2015						1,495		2,078		2,264		2,385		2,472		2,501		2,526		2,535
2016								1,449		2,046		2,205		2,308		2,364		2,391		2,422
2017										1,693		2,514		2,661		2,793		2,863		2,930
2018												1,922		2,542		2,699		2,857		2,971
2019														1,663		2,431		2,610		2,718
2020																1,330		1,990		2,223
2021																		1,583		2,368
2022																				1,411
Total																				$	23,607

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	26
Accident years 2013 - 2022 from tables above	3,199
All Accident years	$	3,225

This product line comprises D&O liability, E&O liability, financial institutions (including crime/fidelity coverages), and non-U.S. general liability as well as aviation and political risk. Exposures are located around the world, including Europe, Latin America, and Asia. Approximately 45 percent of Chubb Overseas General business is generated by European accounts, exclusive of Lloyd's market. There is some U.S. exposure in Casualty from multinational accounts and in financial lines for Lloyd's market. The financial lines coverages are typically written on a claims-made form, while general liability coverages are typically on an occurrence basis and comprises a mix of primary and excess businesses.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	1,186	$	1,181		$	1,174	$	1,217	$	1,172	$	1,139	$	1,084	$	1,054	$	1,074	$	1,094	$	65	37
2014			1,186			1,253		1,261		1,277		1,197		1,118		1,081		1,092		1,096		100		38
2015						1,107		1,199		1,226		1,248		1,229		1,172		1,157		1,174		131		40
2016								1,138		1,234		1,298		1,327		1,317		1,328		1,263		117		42
2017										1,128		1,224		1,271		1,318		1,283		1,319		149		43
2018												1,224		1,273		1,332		1,375		1,330		282		43
2019														1,295		1,360		1,382		1,373		358		42
2020																1,669		1,589		1,509		835		34
2021																		1,604		1,650		1,111		35
2022																				1,741		1,475		29
Total																				$	13,549

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	78	$	246		$	393	$	532	$	667	$	763	$	826	$	875	$	896	$	913
2014			104			273		440		567		675		754		815		857		886
2015						79		265		460		631		745		821		895		927
2016								119		303		500		642		760		851		974
2017										90		296		494		647		805		931
2018												104		309		465		602		718
2019														116		313		440		642
2020																101		271		425
2021																		110		268
2022																				83
Total																				$	6,767

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	505
Accident years 2013 - 2022 from tables above	6,782
All Accident years	$	7,287

This product line is comprised of commercial fire, marine (predominantly cargo), surety, personal automobile (in Latin America, Asia Pacific and Japan), personal cell phones, personal residential (including high net worth), energy, and construction. In general, these lines have relatively stable payment and reporting patterns although they are impacted by natural catastrophes mainly in the 2017, 2018, and 2022 accident years. For the Chubb Overseas General non-casualty book, Europe, exclusive of Lloyd's market, makes up about one third, Latin America makes up about one quarter, and Asia makes up about one fifth.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	1,656	$	1,651		$	1,590	$	1,545	$	1,540	$	1,513	$	1,501	$	1,492	$	1,483	$	1,481	$	12	560
2014			1,727			1,790		1,737		1,725		1,691		1,682		1,675		1,669		1,661		5		534
2015						1,815		1,932		1,907		1,876		1,860		1,853		1,836		1,835		7		557
2016								1,920		1,914		1,901		1,880		1,883		1,913		1,911		35		566
2017										2,067		2,107		2,093		2,075		2,099		2,096		23		577
2018												2,022		2,107		2,070		2,044		2,013		39		612
2019														2,044		2,060		2,000		1,989		(15)		631
2020																2,378		2,244		2,120		164		533
2021																		2,462		2,374		241		541
2022																				2,728		696		597
Total																				$	20,208

Overseas General Insurance — Non-Casualty — Short-tail (continued)
Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	643	$	1,186		$	1,369	$	1,399	$	1,433	$	1,451	$	1,458	$	1,461	$	1,458	$	1,458
2014			699			1,327		1,526		1,585		1,614		1,627		1,641		1,648		1,641
2015						789		1,437		1,656		1,732		1,754		1,781		1,798		1,801
2016								938		1,554		1,740		1,807		1,831		1,840		1,845
2017										980		1,726		1,893		1,964		2,004		2,062
2018												930		1,620		1,812		1,878		1,893
2019														979		1,620		1,804		1,869
2020																1,003		1,602		1,746
2021																		944		1,692
2022																				1,122
Total																				$	17,129

(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	127
Accident years 2013 - 2022 from tables above	3,079
All Accident years	$	3,206

This product line includes proportional and excess coverages in general, automobile liability, professional liability, medical malpractice, and workers' compensation, with exposures located around the world. In general, reinsurance exhibits less stable development patterns than primary business. In particular, general casualty reinsurance and excess coverages are long-tailed and can be very volatile.

Global Reinsurance — Casualty — Long-tail (continued)
Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31  2022
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	317	$	323		$	326	$	326	$	327	$	320	$	313	$	307	$	305	$	302	$	6
2014			329			330		335		338		339		343		326		326		325		8
2015						280		285		295		296		304		300		304		306		11
2016								218		222		230		229		238		238		243		11
2017										208		210		214		212		213		212		4
2018												237		240		247		243		246		12
2019														232		240		236		235		37
2020																241		245		236		60
2021																		277		281		136
2022																				293		206
Total																				$	2,679

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	64	$	142		$	185	$	221	$	240	$	258	$	266	$	269	$	275	$	279
2014			91			183		216		247		262		273		283		292		297
2015						89		157		189		215		230		247		263		272
2016								56		111		140		157		172		189		205
2017										46		98		120		137		152		172
2018												40		93		122		145		166
2019														39		88		114		137
2020																41		98		123
2021																		35		86
2022																				39
Total																				$	1,776

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	305
Accident years 2013 - 2022 from tables above	903
All Accident years	$	1,208

This product line includes property, property catastrophe, marine, credit/surety, mortgage, A&H and energy. This product line is impacted by natural catastrophes, particularly in the 2017, 2018, 2020, 2021, and 2022 accident years. Of the non-catastrophe book, the mixture of business varies by year with approximately 85 percent of loss on proportional treaties in treaty year 2013 and after. This percentage has increased over time with the proportion being approximately 79 percent for treaty years 2013-2017 growing to an average of 91 percent for treaty years 2018 to 2022, with the remainder being written on an excess of loss basis.

Net Incurred Loss and Allocated Loss Adjustment Expenses																						As of December 31  2022
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	157	$	154		$	143	$	137	$	139	$	136	$	136	$	135	$	134	$	134	$	—
2014			159			175		174		177		175		174		173		172		170		1
2015						144		152		158		158		151		156		154		154		—
2016								176		182		184		187		183		181		181		2
2017										395		421		451		449		453		456		12
2018												279		287		290		286		291		7
2019														132		130		127		121		8
2020																209		253		277		34
2021																		340		350		43
2022																				346		220
Total																				$	2,480

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2013		2014			2015		2016		2017		2018		2019		2020		2021		2022
2013	$	45	$	100		$	118	$	127	$	130	$	132	$	133	$	134	$	134	$	134
2014			63			125		147		157		162		164		166		166		167
2015						56		102		130		140		144		148		150		151
2016								56		129		155		166		172		175		176
2017										191		321		400		414		427		433
2018												94		250		266		269		273
2019														35		81		95		103
2020																62		177		215
2021																		158		277
2022																				74
Total																				$	2,003

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	17
Accident years 2013 - 2022 from tables above	477
All Accident years	$	494

Supplementary PPD [Table Text Block]

North America Commercial P&C Insurance — Workers' Compensation — Long-tail (continued)
Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	(132)
Accident years 2013 - 2022 from tables above	(305)
All Accident years	$	(437)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	98
Accident years 2013 - 2022 from tables above	145
All Accident years	$	243

North America Commercial P&C Insurance — Other-Casualty — Long-tail (continued)
Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	56
Accident years 2013 - 2022 from tables above	77
All Accident years	$	133

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	(11)
Accident years 2013 - 2022 from tables above	(319)
All Accident years	$	(330)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	(5)
Accident years 2013 - 2022 from tables above	(123)
All Accident years	$	(128)

Overseas General Insurance — Casualty — Long-tail (continued)
Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	8
Accident years 2013 - 2022 from tables above	(76)
All Accident years	$	(68)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	(10)
Accident years 2013 - 2022 from tables above	(270)
All Accident years	$	(280)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	(7)
Accident years 2013 - 2022 from tables above	(1)
All Accident years	$	(8)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2022
Accident years prior to 2013	$	(4)
Accident years 2013 - 2022 from tables above	34
All Accident years	$	30

Schedule of Historical Claims [Table Text Block]

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	10	%	16	%	10	%	7	%	5	%	3	%	3	%	2	%	2	%	1	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	4	%	13	%	16	%	16	%	12	%	8	%	5	%	4	%	2	%	3	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	11	%	19	%	19	%	16	%	13	%	6	%	4	%	2	%	2	%	1	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	45	%	36	%	8	%	3	%	1	%	1	%	1	%	—	%	—	%	1	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	56	%	24	%	7	%	5	%	3	%	2	%	1	%	1	%	—	%	—	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	7	%	14	%	13	%	12	%	10	%	8	%	7	%	4	%	2	%	2	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	45	%	34	%	10	%	3	%	1	%	1	%	1	%	—	%	—	%	—	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	20	%	23	%	11	%	9	%	6	%	6	%	4	%	2	%	2	%	1	%

Global Reinsurance — Non-Casualty — Short-tail (continued)
Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2022 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	34	%	40	%	15	%	5	%	3	%	2	%	1	%	—	%	—	%	—	%

Supplementary PPD Reconciliation [Table Text Block]

The following table presents a reconciliation of the loss development triangles above to prior period development:

	Components of PPD
Year Ended December 31, 2022 (in millions of U.S. dollars) (favorable)/unfavorable	2013 - 2021 accident years (implied PPD per loss triangles)		Accident years prior to 2013		Other (1)			PPD on loss reserves		RIPs, Expense adjustments, and earned premiums			Total
North America Commercial P&C Insurance
Long-tail	$	(83)	$	22	$	(253)		$	(314)	$	85		$	(229)
Short-tail	(319)		(11)		(30)			(360)		27			(333)
	(402)		11		(283)		(2)	(674)		112		(3)	(562)
North America Personal P&C Insurance (Short-tail)	(123)		(5)		(58)		(4)	(186)		—			(186)
Overseas General Insurance
Long-tail	(76)		8		3			(65)		—			(65)
Short-tail	(270)		(10)		(103)			(383)		—			(383)
	(346)		(2)		(100)		(5)	(448)		—			(448)
Global Reinsurance
Long-tail	(1)		(7)		1			(7)		—			(7)
Short-tail	34		(4)		—			30		(1)			29
	33		(11)		1			23		(1)			22
Subtotal	$	(838)	$	(7)	$	(440)		$	(1,285)	$	111		$	(1,174)
North America Agricultural Insurance (Short-tail)								$	(227)	$	166		$	(61)
Corporate (Long-tail)								359		—			359
Consolidated PPD								$	(1,153)	$	277		$	(876)

(1)        Other includes the impact of foreign exchange.

(2)     Includes favorable development of $161 million related to our Alternative Risk Solutions business (U.S. and Bermuda) and an adjustment to exclude $46 million in unfavorable development in the workers' compensation line, associated with an increase in exposure for which additional premiums were collected; the remaining difference relates to a number of other items, none of which are individually material.

(3)     Includes premium returns associated with our Alternative Risk Solutions business, which is excluded from the triangles.

(4)     Includes $48 million relating to the Colorado Wildfire CAT event that began December 30, 2021.

(5)     Includes favorable development of $105 million related to International A&H business; the remaining difference relates to a number of other items, none of which are individually material.

Prior Period Development, by Segment [Table Text Block]

Years Ended December 31 (in millions of U.S. dollars, except for percentages)	Long-tail		Short-tail		Total		% of beginning net unpaid reserves (1)
2022
North America Commercial P&C Insurance	$	(229)	$	(333)	$	(562)	1.0	%
North America Personal P&C Insurance	—		(186)		(186)		0.3	%
North America Agricultural Insurance	—		(61)		(61)		0.1	%
Overseas General Insurance	(65)		(383)		(448)		0.8	%
Global Reinsurance	(7)		29		22		—	%
Corporate	359		—		359		0.6	%
Total	$	58	$	(934)	$	(876)	1.5	%
2021
North America Commercial P&C Insurance	$	(482)	$	(280)	$	(762)	1.4	%
North America Personal P&C Insurance	—		(305)		(305)		0.6	%
North America Agricultural Insurance	—		10		10		—	%
Overseas General Insurance	(106)		(335)		(441)		0.8	%
Global Reinsurance	(25)		28		3		—	%
Corporate	569		—		569		1.1	%
Total	$	(44)	$	(882)	$	(926)	1.7	%
2020
North America Commercial P&C Insurance	$	(672)	$	(30)	$	(702)	1.4	%
North America Personal P&C Insurance	—		63		63		0.1	%
North America Agricultural Insurance	—		(10)		(10)		—	%
Overseas General Insurance	(49)		(101)		(150)		0.3	%
Global Reinsurance	(25)		(4)		(29)		0.1	%
Corporate	433		—		433		0.9	%
Total	$	(313)	$	(82)	$	(395)	0.8	%

(1)     Calculated based on the beginning of period consolidated net unpaid losses and loss expenses.

Schedule Of Asbestos Environmental Loss Roll Forward and by segment

The following table presents a roll-forward of consolidated A&E loss reserves including allocated loss expense reserves for A&E exposures, and the valuation allowance for uncollectible paid and unpaid reinsurance recoverables:

	Asbestos				Environmental				Total
(in millions of U.S. dollars)	Gross		Net		Gross		Net		Gross		Net
Balance at December 31, 2019	$	1,459	$	916	$	529	$	410	$	1,988	$	1,326
Incurred activity	150		90		79		41		229		131		(1)
Paid activity	(258)		(133)		(91)		(72)		(349)		(205)
Balance at December 31, 2020	1,351		873		517		379		1,868		1,252
Incurred activity	96		64		52		40		148		104		(1)
Paid activity	(221)		(137)		(167)		(117)		(388)		(254)
Balance at December 31, 2021	1,226		800		402		302		1,628		1,102
Incurred activity	87		55		125		77		212		132		(1)
Paid activity	(215)		(152)		(115)		(69)		(330)		(221)
Balance at December 31, 2022	$	1,098	$	703	$	412	$	310	$	1,510	$	1,013

(1)     Excludes unallocated loss expenses and the net activity reflects third-party reinsurance other than the aggregate excess of loss reinsurance provided by National Indemnity Company (NICO) to Westchester Specialty (see Westchester Specialty section below).

The A&E net loss reserves including allocated loss expense reserves and valuation allowance for uncollectible reinsurance at December 31, 2022 and 2021, shown in the table above is comprised of:

	December 31
(in millions of U.S. dollars)	2022		2021
Brandywine operations	$	602	$	646
Westchester Specialty	98		100
Chubb Corp	266		286
Other, mainly Overseas General Insurance	47		70
Total	$	1,013	$	1,102