Unpaid losses and loss expenses (Tables)

12 Months Ended

Dec. 31, 2021

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, 2021 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)	2021		2020		2019
Gross unpaid losses and loss expenses, beginning of year	$	67,811	$	62,690	$	62,960
Reinsurance recoverable on unpaid losses (1)	(14,647)		(14,181)		(14,689)
Net unpaid losses and loss expenses, beginning of year	53,164		48,509		48,271
Net losses and loss expenses incurred in respect of losses occurring in:
Current year	22,966		22,124		19,575
Prior years (2)	(986)		(414)		(845)
Total	21,980		21,710		18,730
Net losses and loss expenses paid in respect of losses occurring in:
Current year	7,836		7,782		7,894
Prior years	10,048		9,652		10,579
Total	17,884		17,434		18,473
Foreign currency revaluation and other	(501)		379		(19)
Net unpaid losses and loss expenses, end of year	56,759		53,164		48,509
Reinsurance recoverable on unpaid losses (1)	16,184		14,647		14,181
Gross unpaid losses and loss expenses, end of year	$	72,943	$	67,811	$	62,690

(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 $60 million, $19 million, and $53 million for 2021, 2020, and 2019, 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, 2021
Presented in the loss development tables:
North America Commercial P&C Insurance — Workers' Compensation	$	9,942
North America Commercial P&C Insurance — Liability	18,736
North America Commercial P&C Insurance — Other Casualty	2,304
North America Commercial P&C Insurance — Non-Casualty	2,963
North America Personal P&C Insurance	3,035
Overseas General Insurance — Casualty	7,052
Overseas General Insurance — Non-Casualty	2,984
Global Reinsurance — Casualty	1,191
Global Reinsurance — Non-Casualty	372
Excluded from the loss development tables:
Other	5,361
Net unpaid loss and allocated loss adjustment expense	53,940
Ceded unpaid loss and allocated loss adjustment expense:
North America Commercial P&C Insurance — Workers' Compensation	1,379
North America Commercial P&C Insurance — Liability	6,263
North America Commercial P&C Insurance — Other Casualty	638
North America Commercial P&C Insurance — Non-Casualty	1,631
North America Personal P&C Insurance	632
Overseas General Insurance — Casualty	2,363
Overseas General Insurance — Non-Casualty	1,868
Global Reinsurance — Casualty	33
Global Reinsurance — Non-Casualty	89
Other	1,414
Ceded unpaid loss and allocated loss adjustment expense	16,310
Unpaid loss and loss expense on other than short-duration contracts (1)	1,090
Unpaid unallocated loss adjustment expenses	1,603
Unpaid losses and loss expenses	$	72,943

(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 substantial geographic spread and a broad mix across industries. 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-58.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	1,050	$	1,011		$	1,030	$	1,040	$	1,011	$	989	$	986	$	977	$	953	$	952	$	224	44
2013			1,109			1,108		1,122		1,127		1,086		1,073		1,037		1,014		989		252		43
2014						1,207		1,201		1,217		1,215		1,163		1,100		1,073		1,037		305		45
2015								1,282		1,259		1,276		1,279		1,217		1,154		1,128		379		50
2016										1,367		1,361		1,383		1,378		1,269		1,206		439		52
2017												1,413		1,380		1,399		1,393		1,376		679		50
2018														1,359		1,361		1,379		1,385		681		51
2019																1,391		1,384		1,401		718		47
2020																		1,367		1,387		903		31
2021																				1,348		1,033		30
Total																				$	12,209

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	111	$	271		$	365	$	436	$	486	$	532	$	574	$	592	$	612	$	626
2013			107			286		422		506		553		587		616		633		650
2014						113		295		410		484		532		566		599		617
2015								116		301		418		501		564		606		628
2016										122		326		452		529		584		621
2017												120		313		437		516		564
2018														130		329		451		528
2019																143		341		467
2020																		111		282
2021																				120
Total																				$	5,103

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	2,836
Accident years 2012 - 2021 from tables above	7,106
All Accident years	$	9,942

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

This line consists of primary and excess 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 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 2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	3,552	$	3,628		$	3,614	$	3,565	$	3,525	$	3,427	$	3,331	$	3,235	$	3,235	$	3,308	$	302	25
2013			3,547			3,542		3,543		3,533		3,430		3,216		3,122		2,964		2,956		252		25
2014						3,535		3,586		3,675		3,718		3,656		3,470		3,346		3,198		381		24
2015								3,560		3,709		3,819		3,977		3,943		3,736		3,709		714		27
2016										3,534		3,595		3,692		3,805		3,799		3,771		773		27
2017												3,322		3,499		3,581		3,631		3,552		1,156		27
2018														3,375		3,494		3,697		3,828		1,445		28
2019																3,452		3,628		3,867		1,982		30
2020																		4,106		3,832		2,780		24
2021																				4,322		3,941		25
Total																				$	36,343

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	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	166	$	656		$	1,172	$	1,680	$	2,093	$	2,327	$	2,502	$	2,619	$	2,688	$	2,783
2013			130			548		1,192		1,597		2,007		2,232		2,374		2,465		2,525
2014						164		679		1,250		1,804		2,202		2,442		2,584		2,673
2015								138		605		1,206		1,856		2,291		2,533		2,749
2016										171		663		1,336		1,975		2,334		2,596
2017												161		617		1,162		1,701		2,003
2018														190		754		1,303		1,777
2019																176		671		1,248
2020																		152		590
2021																				175
Total																				$	19,119

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	1,512
Accident years 2012 - 2021 from tables above	17,224
All Accident years	$	18,736

This product line consists of the remaining commercial casualty coverages such as automobile liability and aviation. There is also a small portion of commercial multi-peril (CMP) business in accident years 2014 and prior. The paid and reported data are impacted by some catastrophe loss activity primarily on the CMP exposures just noted.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	634	$	606		$	577	$	561	$	520	$	519	$	509	$	507	$	505	$	500	$	2	16
2013			527			531		523		516		469		462		462		458		461		12		18
2014						595		583		581		597		555		539		539		531		14		17
2015								487		470		502		515		458		455		463		31		15
2016										504		502		527		524		481		480		51		16
2017												532		566		577		616		605		79		17
2018														536		564		575		580		110		17
2019																606		637		686		219		16
2020																		646		634		372		11
2021																				675		515		9
Total																				$	5,615

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	69	$	223		$	320	$	387	$	435	$	470	$	487	$	493	$	502	$	496
2013			69			197		271		348		385		412		419		426		439
2014						80		220		317		391		455		473		501		509
2015								47		137		215		305		371		395		412
2016										52		145		246		324		375		398
2017												66		175		313		381		446
2018														74		169		270		365
2019																70		190		318
2020																		53		151
2021																				60
Total																				$	3,594

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	283
Accident years 2012 - 2021 from tables above	2,021
All Accident years	$	2,304

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 also impacted by natural catastrophes mainly in the 2012, 2017, and 2018 accident years.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	2,033	$	1,916		$	1,883	$	1,864	$	1,859	$	1,847	$	1,844	$	1,850	$	1,844	$	1,848	$	5	426
2013			1,434			1,424		1,337		1,360		1,340		1,340		1,338		1,344		1,343		5		455
2014						1,643		1,661		1,579		1,559		1,549		1,550		1,558		1,552		3		483
2015								1,736		1,745		1,650		1,638		1,605		1,589		1,592		(6)		545
2016										1,911		1,890		1,800		1,782		1,818		1,832		34		650
2017												2,704		2,608		2,504		2,521		2,513		51		763
2018														2,053		2,240		2,175		2,167		41		903
2019																2,052		2,037		1,959		67		1,042
2020																		3,148		2,951		357		1,118
2021																				2,947		1,249		726
Total																				$	20,704

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	715	$	1,577		$	1,698	$	1,767	$	1,795	$	1,822	$	1,816	$	1,842	$	1,844	$	1,839
2013			651			1,138		1,238		1,285		1,311		1,324		1,333		1,335		1,336
2014						820		1,373		1,484		1,506		1,532		1,546		1,554		1,558
2015								727		1,343		1,488		1,556		1,572		1,574		1,587
2016										846		1,505		1,656		1,733		1,760		1,786
2017												979		2,087		2,302		2,392		2,406
2018														1,027		1,825		2,018		2,074
2019																1,030		1,677		1,804
2020																		1,396		2,271
2021																				1,087
Total																				$	17,748

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, 2021
Accident years prior to 2012	$	7
Accident years 2012 - 2021 from tables above	2,956
All Accident years	$	2,963

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. A portfolio acquired from Fireman’s Fund is presented on a prospective basis beginning in May of accident year 2015. Reserves associated with prior accident periods were acquired through a loss portfolio transfer, which does not allow for a retrospective presentation. During this ten-year period, this segment was also impacted by natural catastrophes, mainly in 2012, 2017 and 2018 accident years.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	2,186	$	2,183		$	2,183	$	2,191	$	2,186	$	2,186	$	2,189	$	2,194	$	2,190	$	2,188	$	5	188
2013			1,860			1,889		1,897		1,900		1,925		1,937		1,945		1,948		1,949		23		132
2014						2,205		2,206		2,192		2,146		2,160		2,147		2,141		2,141		11		144
2015								2,495		2,550		2,561		2,544		2,563		2,570		2,566		12		148
2016										2,440		2,536		2,545		2,482		2,471		2,464		27		154
2017												3,035		3,069		3,002		2,998		2,998		63		163
2018														3,010		3,037		3,103		3,118		197		169
2019																2,957		2,993		2,994		209		156
2020																		2,931		2,634		376		121
2021																				3,037		1,025		103
Total																				$	26,089

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	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	1,177	$	1,806		$	1,957	$	2,063	$	2,117	$	2,150	$	2,164	$	2,164	$	2,165	$	2,177
2013			1,043			1,505		1,688		1,787		1,843		1,885		1,895		1,917		1,916
2014						1,310		1,765		1,926		2,035		2,080		2,106		2,116		2,123
2015								1,499		2,084		2,271		2,392		2,478		2,508		2,533
2016										1,453		2,052		2,211		2,314		2,370		2,398
2017												1,698		2,520		2,668		2,799		2,870
2018														1,926		2,549		2,706		2,865
2019																1,668		2,437		2,617
2020																		1,334		1,995
2021																				1,587
Total																				$	23,081

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	27
Accident years 2012 - 2021 from tables above	3,008
All Accident years	$	3,035

This product line is comprised of 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 46 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 comprised of a mix of primary and excess businesses.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	1,249	$	1,219		$	1,282	$	1,300	$	1,297	$	1,287	$	1,267	$	1,257	$	1,227	$	1,237	$	62	38
2013			1,238			1,234		1,230		1,274		1,228		1,195		1,137		1,104		1,124		73		39
2014						1,237		1,307		1,316		1,331		1,248		1,165		1,125		1,134		101		40
2015								1,153		1,249		1,278		1,301		1,278		1,219		1,202		137		42
2016										1,189		1,289		1,356		1,385		1,373		1,382		286		43
2017												1,180		1,282		1,330		1,379		1,343		205		44
2018														1,279		1,330		1,392		1,434		493		44
2019																1,354		1,422		1,447		620		42
2020																		1,740		1,656		1,101		34
2021																				1,678		1,373		29
Total																				$	13,637

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	72	$	244		$	427	$	577	$	690	$	828	$	898	$	940	$	1,005	$	1,061
2013			82			258		412		557		699		799		866		917		938
2014						107		283		457		588		701		784		847		890
2015								82		276		478		655		774		853		929
2016										123		313		517		664		787		883
2017												94		310		516		676		842
2018														109		322		485		627
2019																121		327		459
2020																		105		283
2021																				116
Total																				$	7,028

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	443
Accident years 2012 - 2021 from tables above	6,609
All Accident years	$	7,052

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 and 2018 accident years. Europe and Asia each make up about one third of the Chubb Overseas General non-casualty book.

Net Incurred Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31						As of December 31 2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves		Reported Claims (in thousands)
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	1,634	$	1,624		$	1,584	$	1,531	$	1,524	$	1,516	$	1,501	$	1,496	$	1,489	$	1,488	$	4	555
2013			1,703			1,698		1,635		1,589		1,584		1,557		1,545		1,536		1,527		12		573
2014						1,774		1,839		1,785		1,775		1,740		1,730		1,723		1,717		(3)		548
2015								1,867		1,985		1,963		1,933		1,915		1,908		1,890		3		570
2016										1,975		1,973		1,960		1,938		1,942		1,972		38		581
2017												2,122		2,161		2,143		2,125		2,149		15		589
2018														2,083		2,169		2,132		2,109		29		623
2019																2,098		2,117		2,049		22		640
2020																		2,448		2,309		250		541
2021																				2,521		699		531
Total																				$	19,731

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	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	643	$	1,176		$	1,357	$	1,415	$	1,437	$	1,447	$	1,458	$	1,461	$	1,460	$	1,471
2013			659			1,221		1,410		1,441		1,477		1,495		1,502		1,505		1,503
2014						718		1,365		1,571		1,633		1,662		1,675		1,689		1,696
2015								811		1,481		1,707		1,786		1,807		1,836		1,853
2016										959		1,597		1,791		1,861		1,886		1,895
2017												1,000		1,765		1,938		2,012		2,052
2018														954		1,668		1,868		1,936
2019																996		1,657		1,849
2020																		1,031		1,649
2021																				962
Total																				$	16,866

(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	119
Accident years 2012 - 2021 from tables above	2,865
All Accident years	$	2,984

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  2021
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	386	$	382		$	391	$	393	$	378	$	372	$	371	$	373	$	378	$	376	$	5
2013			320			326		329		329		331		323		316		310		309		10
2014						332		333		339		342		343		346		329		330		11
2015								284		288		299		300		308		304		308		14
2016										223		226		235		234		243		243		16
2017												213		215		219		217		218		17
2018														244		247		254		250		25
2019																238		246		241		56
2020																		246		250		97
2021																				281		196
Total																				$	2,806

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	78	$	168		$	222	$	262	$	293	$	308	$	324	$	335	$	341	$	347
2013			65			143		186		222		241		260		269		271		278
2014						91		184		217		248		264		276		286		295
2015								90		158		191		217		232		249		266
2016										57		113		142		159		175		192
2017												46		100		122		140		155
2018														41		96		125		149
2019																40		90		116
2020																		41		99
2021																				35
Total																				$	1,932

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	317
Accident years 2012 - 2021 from tables above	874
All Accident years	$	1,191

This product line includes property, property catastrophe, marine, credit/surety, A&H and energy. This product line is impacted by natural catastrophes, particularly in the 2017, 2018, 2020, and 2021 accident years. Of the non-catastrophe book, the mixture of business varies by year with approximately 79 percent of loss on proportional treaties in treaty year 2012 and after. This percentage has increased over time with the proportion being approximately 54 percent for treaty year 2012 growing to an average of 83 percent for treaty years 2013 to 2021, with the remainder being written on an excess of loss basis.

Net Incurred Loss and Allocated Loss Adjustment Expenses																						As of December 31  2021
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited																	Net IBNR Reserves
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	232	$	211		$	201	$	192	$	190	$	188	$	185	$	185	$	183	$	184	$	1
2013			160			158		146		141		142		140		140		139		138		—
2014						164		179		179		182		181		179		178		177		1
2015								146		154		161		161		153		159		157		1
2016										182		187		189		192		188		186		2
2017												396		423		453		450		454		13
2018														285		295		299		294		1
2019																139		137		133		18
2020																		211		255		34
2021																				342		131
Total																				$	2,320

Net Cumulative Paid Loss and Allocated Loss Adjustment Expenses
																Years Ended December 31
(in millions of U.S. dollars)					Unaudited
Accident Year	2012		2013			2014		2015		2016		2017		2018		2019		2020		2021
2012	$	45	$	130		$	156	$	166	$	172	$	177	$	180	$	180	$	179	$	179
2013			46			102		120		130		133		135		136		137		137
2014						65		128		151		162		167		170		172		172
2015								56		103		132		142		146		151		152
2016										57		132		159		170		176		180
2017												191		322		401		415		428
2018														94		255		273		276
2019																35		84		99
2020																		62		178
2021																				158
Total																				$	1,959

Net Liabilities for Loss and Allocated Loss Adjustment Expenses
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	11
Accident years 2012 - 2021 from tables above	361
All Accident years	$	372

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, 2021
Accident years prior to 2012	$	(98)
Accident years 2012 - 2021 from tables above	(125)
All Accident years	$	(223)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	(86)
Accident years 2012 - 2021 from tables above	(121)
All Accident years	$	(207)

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, 2021
Accident years prior to 2012	$	(7)
Accident years 2012 - 2021 from tables above	28
All Accident years	$	21

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	(3)
Accident years 2012 - 2021 from tables above	(277)
All Accident years	$	(280)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	(2)
Accident years 2012 - 2021 from tables above	(293)
All Accident years	$	(295)

Overseas General Insurance — Casualty — Long-tail (continued)
Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	(76)
Accident years 2012 - 2021 from tables above	(22)
All Accident years	$	(98)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	(6)
Accident years 2012 - 2021 from tables above	(210)
All Accident years	$	(216)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	(27)
Accident years 2012 - 2021 from tables above	(2)
All Accident years	$	(29)

Supplementary Information: (Favorable)/ Adverse Prior Period Development
(in millions of U.S. dollars)	December 31, 2021
Accident years prior to 2012	$	(4)
Accident years 2012 - 2021 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, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	10	%	15	%	10	%	7	%	5	%	4	%	3	%	2	%	2	%	1	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	4	%	14	%	17	%	15	%	11	%	7	%	5	%	3	%	2	%	3	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	11	%	21	%	19	%	15	%	11	%	5	%	3	%	1	%	2	%	—	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	45	%	37	%	8	%	3	%	1	%	1	%	—	%	1	%	—	%	—	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	56	%	24	%	6	%	5	%	3	%	1	%	1	%	—	%	—	%	1	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	7	%	14	%	14	%	12	%	10	%	8	%	6	%	4	%	4	%	5	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	44	%	34	%	10	%	3	%	2	%	1	%	1	%	—	%	—	%	1	%

Supplementary Information: Average Annual Percentage Payout of Net Incurred Claims by Age, as of December 31, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	21	%	24	%	12	%	9	%	6	%	5	%	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, 2021 (Unaudited)
Age in Years	1		2		3		4		5		6		7		8		9		10
Percentage	35	%	40	%	14	%	4	%	3	%	2	%	1	%	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, 2021 (in millions of U.S. dollars) (favorable)/unfavorable	2012 - 2020 accident years (implied PPD per loss triangles)		Accident years prior to 2012		Other (1)			PPD on loss reserves		RIPs, Expense adjustments, and earned premiums			Total
North America Commercial P&C Insurance
Long-tail	$	(218)	$	(191)	$	(142)		$	(551)	$	69		$	(482)
Short-tail	(277)		(3)		(10)			(290)		10			(280)
	(495)		(194)		(152)		(2)	(841)		79		(3)	(762)
North America Personal P&C Insurance (Short-tail)	(293)		(2)		(9)			(304)		(1)			(305)
Overseas General Insurance
Long-tail	(22)		(76)		(8)			(106)		—			(106)
Short-tail	(210)		(6)		(126)			(342)		7			(335)
	(232)		(82)		(134)		(4)	(448)		7			(441)
Global Reinsurance
Long-tail	(2)		(27)		1			(28)		3			(25)
Short-tail	34		(4)		(2)			28		—			28
	32		(31)		(1)			—		3			3
Subtotal	$	(988)	$	(309)	$	(296)		$	(1,593)	$	88		$	(1,505)
North America Agricultural Insurance (Short-tail)								$	38	$	(28)		$	10
Corporate (Long-tail)								569		—			569
Consolidated PPD								$	(986)	$	60		$	(926)

(1)        Other includes the impact of foreign exchange.

(2)     Includes favorable development of $96 million related to our Alternative Risk Solutions business (U.S. and Bermuda) and an adjustment to exclude $48 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 favorable development of $118 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)
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	%
2019
North America Commercial P&C Insurance	$	(668)	$	19	$	(649)	1.3	%
North America Personal P&C Insurance	—		(95)		(95)		0.2	%
North America Agricultural Insurance	—		(80)		(80)		0.2	%
Overseas General Insurance	(68)		(24)		(92)		0.2	%
Global Reinsurance	(59)		30		(29)		0.1	%
Corporate	153		—		153		0.3	%
Total	$	(642)	$	(150)	$	(792)	1.6	%

(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, 2018	$	1,492	$	964	$	625	$	483	$	2,117	$	1,447
Incurred activity	129		70		46		28		175		98		(1)
Paid activity	(162)		(118)		(142)		(101)		(304)		(219)
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

(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, 2021 and 2020 shown in the table above is comprised of:

	December 31
(in millions of U.S. dollars)	2021		2020
Brandywine operations	$	646	$	736
Westchester Specialty	100		103
Chubb Corp	286		333
Other, mainly Overseas General Insurance	70		80
Total	$	1,102	$	1,252