XML 59 R42.htm IDEA: XBRL DOCUMENT v3.22.0.1

Short Duration Contracts (Tables)

12 Months Ended

Dec. 31, 2021

Short Duration Contracts Disclosure [Abstract]

Levels of disaggregation

The Company’s reserves for losses and loss adjustment expenses primarily relate to short-duration contracts with various characteristics (e.g., type of coverage, geography, claims duration). The Company considered such information in determining the level of disaggregation for disclosures related to its short-duration contracts, as detailed in the table below:

Reportable segment

Level of disaggregation

Included lines of business

Insurance

Property energy, marine and aviation

Property energy, marine and aviation

Third party occurrence business

Excess and surplus casualty (excluding contract binding); construction and national accounts; and other (including alternative market risks, excess workers’ compensation and employer’s liability insurance coverages)

Third party claims-made business

Professional lines

Multi-line and other specialty

Programs; contract binding (part of excess and surplus casualty); travel, accident and health; lenders products; and other (contract and commercial surety coverages)

Reinsurance

Casualty

Casualty

Property catastrophe

Property catastrophe

Property excluding property catastrophe

Property excluding property catastrophe

Marine and aviation

Marine and aviation

Other specialty

Other specialty

Mortgage

Direct mortgage insurance in the U.S.

Mortgage insurance on U.S. primary exposures

Claims Development [Line Items]

Reconciliation of claims development to liability

The following table represents a reconciliation of the disclosures of net incurred and paid loss development tables to the reserve for losses and loss adjustment expenses at December 31, 2021:

			December 31, 2021
Net outstanding liabilities
Insurance
Property, energy, marine and aviation			$	586,885
Third party occurrence business			2,885,557
Third party claims-made business			1,613,425
Multi-line and other specialty			1,125,841
Reinsurance
Casualty			2,106,507
Property catastrophe			486,248
Property excluding property catastrophe			724,034
Marine and aviation			245,881
Other specialty			981,805
Mortgage
U.S. primary			688,688
Other short duration lines not included in disclosures			441,459
Total for short duration lines			11,886,330
Unpaid losses and loss adjustment expenses recoverable
Insurance
Property, energy, marine and aviation			354,432
Third party occurrence business			1,537,549
Third party claims-made business			921,086
Multi-line and other specialty			199,485
Reinsurance
Casualty			592,879
Property catastrophe			484,598
Property excluding property catastrophe			118,939
Marine and aviation			111,298
Other specialty			373,292
Mortgage
U.S. primary			48,259
Other short duration lines not included in disclosures (1)			887,457
Intercompany eliminations			(4,146)
Total for short duration lines			5,625,128
Lines other than short duration			76,240
Discounting			(55,575)
Unallocated claims adjustment expenses			225,033
			245,698
Total gross reserves for losses and loss adjustment expenses			$	17,757,156

(1)    Includes unpaid loss and loss adjustment expenses recoverable of $390.1 million related to the loss portfolio transfer reinsurance agreements.

Insurance

Claims Development [Line Items]

Claims development tables

The following tables present information on the insurance segment’s short-duration insurance contracts:

Property, energy, marine and aviation ($000’s except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	233,149					$	232,498					$	205,776					$	199,469					$	197,005					$	192,993					$	190,770					$	178,616					$	178,250					$	178,343					$	627					4,245
2013												159,102						156,785						149,199						143,400						134,952						133,869						128,624						127,290						126,276						25						4,243
2014																		148,368						145,957						147,465						136,201						132,307						134,329						135,032						134,942						3,098						3,884
2015																								112,409						109,865						103,995						102,515						97,852						91,830						91,892						3,804						4,536
2016																														104,449						101,306						105,657						100,471						96,437						92,553						874						6,160
2017																																				280,715						246,291						235,951						230,439						231,228						8,248						6,426
2018																																										180,981						186,030						173,693						170,057						9,136						5,020
2019																																																179,056						178,564						165,477						6,667						5,080
2020																																																						359,394						329,362						66,698						4,186
2021																																																												426,870						158,163						2,951
																																																						Total						$	1,947,000
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	20,638					$	93,394					$	138,977					$	161,831					$	167,540					$	179,945					$	181,307					$	173,184					$	174,032					$	174,384
2013												32,292						84,936						110,808						120,111						122,244						125,475						123,356						124,688						124,841
2014																		25,881						53,751						77,892						84,195						87,812						98,553						115,383						122,296
2015																								23,580						64,953						76,338						86,253						87,926						86,246						87,316
2016																														24,828						83,552						98,683						97,506						95,002						91,241
2017																																				30,228						139,867						195,532						211,708						215,895
2018																																										30,026						102,285						134,858						142,838
2019																																																26,130						105,380						133,911
2020																																																						55,619						194,487
2021																																																												90,423
																														Total																														1,377,632
																														All outstanding liabilities before 2012, net of reinsurance																														17,517
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	586,885

Third party occurrence business ($000’s except claim count)
						Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																												December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	241,368					$	263,451					$	269,204					$	272,004					$	258,371					$	253,758					$	243,863					$	244,448					$	242,332					$	239,075					$	43,924					65,731
2013												283,228						297,225						307,152						302,165						282,122						274,717						272,849						269,754						270,558						54,640						67,113
2014																		330,015						336,019						338,890						343,113						339,701						344,197						342,934						343,569						66,498						75,904
2015																								359,058						391,884						398,908						392,143						391,455						382,722						386,801						91,081						78,785
2016																														389,832						394,485						406,082						399,571						374,896						367,818						115,303						79,005
2017																																				417,377						417,941						422,624						412,512						407,115						145,130						84,692
2018																																										430,415						453,190						450,937						451,459						189,965						77,700
2019																																																456,353						487,547						481,045						253,849						84,895
2020																																																						607,249						616,910						428,750						89,560
2021																																																												622,713						543,386						65,477
																																																						Total						$	4,187,063
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	6,984					$	30,915					$	58,650					$	83,637					$	108,660					$	130,098					$	143,885					$	155,085					$	163,016					$	168,119
2013												6,857						29,265						71,449						101,293						122,288						149,292						164,403						174,946						184,800
2014																		9,228						40,346						71,624						112,702						162,123						191,305						211,643						224,101
2015																								11,139						44,605						88,515						139,492						181,704						211,715						227,697
2016																														11,709						41,979						87,616						136,870						164,662						194,773
2017																																				13,408						52,356						99,874						135,111						165,606
2018																																										17,025						63,848						115,137						154,248
2019																																																18,431						73,222						121,859
2020																																																						24,509						76,743
2021																																																												26,301
																														Total																														1,544,247
																														All outstanding liabilities before 2012, net of reinsurance																														242,741
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	2,885,557

Third party claims-made business ($000’s except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	317,654					$	320,207					$	318,453					$	313,907					$	291,316					$	275,665					$	277,683					$	285,163					$	285,527					$	286,118					$	11,570					15,576
2013												301,956						320,659						324,442						320,524						294,674						291,205						281,996						271,501						273,948						11,739						15,696
2014																		264,537						279,846						299,104						279,043						282,058						298,017						292,247						288,318						22,336						15,676
2015																								258,989						277,615						276,492						260,063						255,432						252,478						267,925						20,617						14,724
2016																														275,394						291,645						308,453						314,747						322,042						327,230						42,509						15,749
2017																																				271,088						286,565						312,554						308,917						323,854						60,718						16,404
2018																																										273,521						315,085						320,653						337,083						85,411						15,854
2019																																																290,217						318,469						318,498						119,673						12,982
2020																																																						384,852						414,580						240,888						10,049
2021																																																												516,420						435,910						8,550
																																																						Total						$	3,353,974
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	17,718					$	69,069					$	121,211					$	164,724					$	190,395					$	209,295					$	227,389					$	251,313					$	255,337					$	260,173
2013												19,032						87,458						137,963						179,395						198,008						217,132						238,951						245,687						247,078
2014																		13,817						63,312						129,712						173,089						208,074						229,958						243,791						249,960
2015																								9,066						52,046						100,089						126,499						174,161						193,186						216,986
2016																														10,568						68,226						127,286						158,230						205,596						242,431
2017																																				9,306						67,669						113,208						143,340						196,125
2018																																										12,287						68,424						118,361						158,709
2019																																																12,418						65,477						122,362
2020																																																						17,161						87,547
2021																																																												23,349
																														Total																														1,804,720
																														All outstanding liabilities before 2012, net of reinsurance																														64,171
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	1,613,425

Multi-line and other specialty ($000’s except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	254,684					$	265,479					$	259,582					$	257,240					$	256,379					$	248,066					$	248,310					$	245,205					$	245,260					$	243,849					$	2,057					55,219
2013												266,089						274,285						265,594						265,672						253,554						254,916						250,252						247,443						246,682						3,461						71,613
2014																		303,053						327,098						319,706						319,418						318,297						314,300						311,097						310,097						5,770						109,575
2015																								335,250						358,587						357,364						365,362						357,123						349,895						347,669						7,201						148,924
2016																														409,367						431,760						428,579						416,724						410,610						408,621						11,032						175,261
2017																																				483,414						502,068						492,166						501,753						505,135						16,867						219,810
2018																																										513,466						565,717						563,969						566,283						32,467						247,052
2019																																																568,337						613,673						641,832						63,880						235,824
2020																																																						622,241						572,265						192,056						149,004
2021																																																												637,258						361,237						75,250
																																																						Total						$	4,479,691
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	78,523					$	166,414					$	190,754					$	209,916					$	223,798					$	232,640					$	233,862					$	237,221					$	240,191					$	239,928
2013												86,911						151,897						181,721						214,941						226,769						235,801						237,863						238,792						239,831
2014																		108,003						197,609						235,079						267,959						282,104						292,638						294,049						295,551
2015																								138,393						236,516						278,265						306,313						321,395						327,082						330,872
2016																														176,238						305,250						342,345						363,392						379,885						385,890
2017																																				181,454						343,049						381,419						424,219						446,749
2018																																										212,316						390,009						443,644						480,852
2019																																																212,629						386,894						488,094
2020																																																						173,123						311,112
2021																																																												157,346
																														Total																														3,376,225
																														All outstanding liabilities before 2012, net of reinsurance																														22,375
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	1,125,841

Percentage annual payout by age

The following table presents the average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance, as of December 31, 2021:

						Average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance
						Year 1						Year 2						Year 3						Year 4						Year 5						Year 6						Year 7						Year 8						Year 9						Year 10
Property, energy, marine and aviation						19.3		%				43.5		%				19.1		%				6.6		%				1.4		%				2.3		%				3.2		%				0.5		%				0.3		%				0.2		%
Third party occurrence business						3.3		%				9.3		%				11.6		%				11.0		%				9.8		%				8.7		%				5.4		%				4.1		%				3.5		%				2.1		%
Third party claims-made business						4.4		%				18.0		%				17.8		%				12.3		%				12.7		%				7.9		%				7.0		%				4.3		%				1.0		%				1.7		%
Multi-line and other specialty						34.7		%				29.5		%				11.0		%				8.6		%				4.6		%				2.8		%				0.7		%				0.7		%				0.8		%				(0.1)		%

Reinsurance

Claims Development [Line Items]

Claims development tables

The following tables present information on the reinsurance segment’s short-duration insurance contracts:

Casualty ($000’s)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	143,029					$	141,202					$	137,049					$	125,104					$	115,131					$	109,788					$	118,457					$	121,721					$	120,260					$	119,222					$	24,441					N/A
2013												166,016						159,257						155,066						148,784						136,717						135,155						131,475						135,762						135,959						30,873						N/A
2014																		216,882						222,109						219,355						233,552						230,019						239,765						240,067						236,378						41,077						N/A
2015																								223,208						221,922						230,830						238,126						242,180						249,029						252,809						57,345						N/A
2016																														215,222						227,534						251,415						266,254						273,266						272,689						54,087						N/A
2017																																				270,728						257,088						273,166						301,616						313,605						66,450						N/A
2018																																										281,141						294,820						285,646						290,955						66,572						N/A
2019																																																336,062						348,015						374,002						120,045						N/A
2020																																																						386,684						374,912						234,251						N/A
2021																																																												445,047						392,885						N/A
																																																						Total						$	2,815,578
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	1,306					$	8,486					$	14,690					$	25,523					$	36,562					$	47,807					$	59,511					$	69,877					$	75,833					$	79,364
2013												2,480						9,930						23,044						43,069						54,567						63,136						70,803						76,703						81,856
2014																		3,920						16,061						40,804						63,441						91,098						114,456						134,529						145,376
2015																								4,463						20,275						47,288						71,098						96,835						120,566						138,035
2016																														5,739						25,649						51,684						86,798						113,835						132,814
2017																																				6,429						30,360						64,075						113,307						137,921
2018																																										7,580						31,218						106,571						129,196
2019																																																15,815						57,643						96,935
2020																																																						17,730						50,603
2021																																																												14,794
																														Total																														1,006,894
																														All outstanding liabilities before 2012, net of reinsurance																														297,823
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	2,106,507

Property catastrophe ($000’s)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	149,957					$	122,942					$	108,590					$	102,114					$	99,885					$	99,071					$	97,037					$	97,145					$	96,531					$	96,447					$	105					N/A
2013												67,257						47,780						36,401						31,902						29,345						28,617						27,727						27,865						27,657						(138)						N/A
2014																		45,159						30,877						25,296						22,412						20,652						19,945						19,841						19,615						(10)						N/A
2015																								33,579						18,075						11,580						5,585						3,775						3,130						2,920						67						N/A
2016																														25,641						18,719						14,575						10,772						8,362						7,426						881						N/A
2017																																				87,504						54,768						50,553						36,846						25,121						(712)						N/A
2018																																										77,868						60,418						41,642						27,657						4,783						N/A
2019																																																38,570						24,808						23,534						4,576						N/A
2020																																																						267,750						334,185						40,561						N/A
2021																																																												316,197						61,821						N/A
																																																						Total						$	880,759
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	25,850					$	70,832					$	83,822					$	90,727					$	92,886					$	94,015					$	94,625					$	95,312					$	95,414					$	95,606
2013												12,200						19,201						24,038						25,894						27,652						27,891						27,892						28,597						28,346
2014																		13,622						19,939						18,402						19,231						18,821						19,013						19,154						19,241
2015																								(3,152)						(2,518)						1,786						2,050						1,616						1,705						1,781
2016																														(6,722)						2,521						2,796						4,082						3,312						3,668
2017																																				30,704						32,228						37,791						27,797						14,969
2018																																										27,497						12,506						24,259						(4,612)
2019																																																3,834						12,680						18,134
2020																																																						53,275						155,063
2021																																																												64,764
																														Total																														396,960
																														All outstanding liabilities before 2012, net of reinsurance																														2,449
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	486,248

Property excluding property catastrophe ($000’s)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	156,162					$	121,808					$	123,689					$	119,124					$	114,699					$	112,477					$	111,001					$	108,436					$	102,994					$	103,367					$	508					N/A
2013												115,473						76,905						70,558						66,208						64,486						63,702						62,504						63,269						62,782						384						N/A
2014																		143,464						117,448						99,328						90,710						88,438						84,130						82,408						80,940						923						N/A
2015																								215,095						189,109						184,774						189,045						188,343						177,281						173,659						8,482						N/A
2016																														177,039						146,307						138,375						136,868						140,681						137,579						12,700						N/A
2017																																				271,713						253,859						240,749						233,153						216,358						13,045						N/A
2018																																										225,638						242,069						238,052						214,942						11,593						N/A
2019																																																216,653						206,997						196,840						17,777						N/A
2020																																																						371,752						343,078						51,075						N/A
2021																																																												552,066						255,343						N/A
																																																						Total						$	2,081,611
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	26,153					$	78,080					$	93,198					$	101,868					$	102,844					$	103,480					$	102,658					$	102,598					$	102,504					$	102,525
2013												25,993						42,737						49,816						52,997						53,796						55,676						61,183						62,113						62,139
2014																		23,496						62,800						71,692						76,634						78,274						78,657						78,567						78,268
2015																								75,622						119,237						149,814						160,848						166,025						159,675						159,925
2016																														33,400						95,616						99,428						104,984						112,838						115,102
2017																																				27,569						125,768						158,066						166,087						181,628
2018																																										30,047						108,863						153,944						169,054
2019																																																43,230						124,222						150,931
2020																																																						101,969						208,888
2021																																																												136,712
																														Total																														1,365,172
																														All outstanding liabilities before 2012, net of reinsurance																														7,595
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	724,034

Marine and aviation ($000’s)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	58,992					$	58,868					$	55,053					$	52,286					$	51,079					$	49,727					$	46,046					$	43,028					$	41,182					$	40,016					$	1,005					N/A
2013												38,881						37,668						36,653						35,251						35,157						34,415						33,970						30,316						27,605						2,394						N/A
2014																		30,958						29,159						27,373						25,674						23,677						23,310						22,031						21,984						4,909						N/A
2015																								33,646						37,505						31,790						31,736						30,789						28,464						27,680						3,867						N/A
2016																														27,351						22,747						23,567						19,273						16,969						15,019						6,708						N/A
2017																																				28,800						26,346						23,830						20,827						19,903						6,387						N/A
2018																																										28,017						26,084						24,615						24,756						6,452						N/A
2019																																																48,929						55,307						60,983						15,112						N/A
2020																																																						83,457						76,598						36,671						N/A
2021																																																												111,046						89,459						N/A
																																																						Total						$	425,590
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	2,658					$	11,433					$	27,528					$	33,313					$	35,055					$	36,257					$	37,746					$	38,038					$	38,131					$	38,116
2013												4,945						13,731						18,415						21,388						22,398						23,672						24,049						23,786						23,753
2014																		4,177						7,985						11,590						12,469						14,645						15,080						15,956						16,036
2015																								7						13,418						19,023						20,861						22,629						22,306						22,445
2016																														(7,333)						(1,687)						521						3,261						5,864						6,767
2017																																				1,660						6,541						9,367						11,030						11,632
2018																																										2,005						6,968						11,236						13,585
2019																																																10,756						21,580						29,068
2020																																																						9,220						26,519
2021																																																												8,643
																														Total																														196,564
																														All outstanding liabilities before 2012, net of reinsurance																														16,855
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	245,881

Other specialty ($000’s)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																		Total of IBNR liabilities plus expected development on reported claims						Cumulative number of reported claims
						Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited						2020 unaudited						2021
2012						$	222,558					$	211,839					$	202,046					$	196,138					$	193,882					$	196,539					$	194,726					$	189,193					$	181,246					$	179,364					$	2,392					N/A
2013												252,744						226,032						216,250						212,721						213,614						211,261						210,825						204,894						201,830						6,409						N/A
2014																		274,826						256,332						258,114						251,474						246,393						248,083						243,652						237,478						7,857						N/A
2015																								209,764						201,057						199,468						196,521						196,840						193,626						182,162						8,549						N/A
2016																														223,191						220,661						215,078						209,564						215,614						210,344						13,182						N/A
2017																																				269,254						258,419						247,203						245,505						241,598						30,855						N/A
2018																																										320,538						316,231						308,190						324,536						40,807						N/A
2019																																																360,854						341,409						326,168						51,165						N/A
2020																																																						533,861						460,084						102,130						N/A
2021																																																												582,446						300,667						N/A
																																																						Total						$	2,946,010
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						$	45,663					$	121,679					$	144,429					$	155,445					$	163,160					$	167,164					$	171,519					$	173,305					$	173,606					$	173,494
2013												57,317						119,445						145,521						161,608						171,189						176,483						183,772						184,111						186,956
2014																		68,869						146,652						182,184						195,433						201,974						212,991						215,597						219,060
2015																								54,359						114,382						138,350						145,419						154,369						162,314						164,471
2016																														65,055						138,648						162,661						174,403						186,247						189,411
2017																																				73,366						164,829						192,274						199,051						205,998
2018																																										71,167						201,732						231,358						245,330
2019																																																79,718						158,132						216,647
2020																																																						97,617						243,980
2021																																																												126,635
																														Total																														1,971,982
																														All outstanding liabilities before 2012, net of reinsurance																														7,777
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	981,805

Percentage annual payout by age

The following table presents the average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance, as of December 31, 2021:

						Average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance
						Year 1						Year 2						Year 3						Year 4						Year 5						Year 6						Year 7						Year 8						Year 9						Year 10
Casualty						2.5		%				7.3		%				11.6		%				11.3		%				9.6		%				8.4		%				7.7		%				5.9		%				4.4		%				3.0		%
Property catastrophe						21.6		%				30.0		%				32.8		%				(14.2)		%				(11.6)		%				2.2		%				1.0		%				1.2		%				(0.4)		%				0.2		%
Property excluding property catastrophe						26.7		%				38.9		%				13.3		%				5.8		%				3.4		%				0.4		%				2.0		%				0.4		%				—		%				—		%
Marine and aviation						4.9		%				26.9		%				19.0		%				10.3		%				7.4		%				2.9		%				2.4		%				—		%				0.1		%				—		%
Other specialty						26.3		%				34.2		%				12.9		%				5.2		%				4.2		%				3.1		%				2.1		%				0.9		%				0.8		%				(0.1)		%

Mortgage

Claims Development [Line Items]

Claims development tables

The following table presents information on the mortgage segment’s short-duration insurance contracts:

U.S. primary mortgage insurance ($000’s except claim count)
Incurred losses and allocated loss adjustment expenses, net of reinsurance																																																																		December 31, 2021
																																																																					Total of IBNR liabilities plus expected development on reported claims						Cumulative number of paid claims
Year ended December 31,
Accident year						2012 unaudited						2013 unaudited						2014 unaudited						2015 unaudited						2016 unaudited						2017 unaudited						2018 unaudited						2019 unaudited									2020 unaudited						2021
2012						$	520,835					$	480,592					$	475,317					$	469,238					$	467,296					$	459,467					$	458,065					$	456,286								$	456,331					$	456,362					1						15,080
2013												469,311						419,668						411,793						405,809						395,693						393,149						390,987									391,062						391,324						1						9,468
2014																		316,095						297,151						279,434						266,027						265,992						261,091									262,682						262,829						4						6,299
2015																								222,790						197,238						198,001						194,677						189,235									190,913						190,560						1						4,554
2016																														183,556						170,532						148,715						140,608									142,392						141,657						1						3,424
2017																																				179,376						132,220						107,255									108,181						109,242						1						2,474
2018																																										132,318						96,357									89,120						87,962						60						1,635
2019																																																108,424									119,253						110,362						181						851
2020																																																									420,003						373,533						2,686						189
2021																																																															144,375						2,246						11
																																																Total															$	2,268,206
Cumulative paid losses and allocated loss adjustment expenses, net of reinsurance
2012						(106,065)						186,605						327,605						395,695						426,024						441,577						448,151						452,348									453,587						453,986
2013												41,447						203,957						308,956						353,189						373,909						382,200						386,853									387,894						387,879
2014																		20,099						129,159						201,925						233,879						247,038						254,175									256,285						256,875
2015																								16,159						92,431						151,222						171,337						180,321									183,472						184,025
2016																														11,462						72,201						113,357						127,286									131,161						131,717
2017																																				8,622						48,112						78,650									87,317						89,756
2018																																										3,966						31,478									50,135						55,853
2019																																																2,899									20,105						29,102
2020																																																									1,040						4,144
2021																																																															469
																																																															1,593,806
																														All outstanding liabilities before 2012, net of reinsurance																														14,288
																								Liabilities for losses and loss adjustment expenses, net of reinsurance																																				$	688,688

Percentage annual payout by age

The following table presents the average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance, as of December 31, 2021:

Average annual percentage payout of incurred losses and allocated loss adjustment expenses by age, net of reinsurance
						Year 1						Year 2						Year 3						Year 4						Year 5						Year 6						Year 7						Year 8						Year 9						Year 10
U.S. Primary						2.7		%				34.9		%				25.3		%				10.5		%				4.4		%				2.1		%				0.9		%				0.5		%				0.1		%				0.1		%

X

- Definition

Short Duration Contracts Disclosure [Abstract]

+ References

No definition available.

+ Details

Name:	acgl_ShortDurationContractsDisclosureAbstract
Namespace Prefix:	acgl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Short Duration Contracts Levels Of Disaggregation [Table Text Block]

+ References

No definition available.

+ Details

Name:	acgl_ShortDurationContractsLevelsOfDisaggregationTableTextBlock
Namespace Prefix:	acgl_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ClaimsDevelopmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of undiscounted information about claims development by accident year for short-duration insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=116884468&loc=SL65671311-158438

+ Details

Name:	us-gaap_ShortdurationInsuranceContractsClaimsDevelopmentTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure for the reconciliation of claims development to the liability for unpaid claims and claim adjustment expense for short-duration insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 4C
-URI http://asc.fasb.org/extlink&oid=116884468&loc=SL65671315-158438

+ Details

Name:	us-gaap_ShortdurationInsuranceContractsReconciliationOfClaimsDevelopmentToLiabilityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of average annual percentage payout of incurred claims by age, after reinsurance, for short-duration insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 4G
-URI http://asc.fasb.org/extlink&oid=116884468&loc=SL65671329-158438

+ Details

Name:	us-gaap_ShortdurationInsuranceContractsScheduleOfHistoricalClaimsDurationTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=acgl_InsuranceSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=acgl_ReinsuranceSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=acgl_MortgageSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: