Claim and Claim Adjustment Expense Reserves (Tables)

12 Months Ended

Dec. 31, 2020

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration insurance contracts, reconciliation of claims development to liability

The table below reconciles the net liability for unpaid claim and claim adjustment expenses to the amount presented on the Consolidated Balance Sheets.

As of December 31
(In millions)	2020
Net liability for unpaid claim and claim adjustment expenses:
Specialty	$	4,898
Commercial	8,204
International	1,822
Corporate & Other	162
Life & Group (1)	3,615
Total net claim and claim adjustment expenses	18,701
Reinsurance receivables: (2)
Specialty	850
Commercial	837
International	269
Corporate & Other (3)	1,921
Life & Group	128
Total reinsurance receivables	4,005
Total gross liability for unpaid claim and claim adjustment expenses	$	22,706

(1) The Life & Group segment amounts are primarily related to long term care claim reserves, but also include amounts related to unfunded structured settlements arising from short-duration contracts. Long term care policies are long-duration contracts.

(2) Reinsurance receivables presented are gross of the allowance for uncollectible reinsurance and do not include reinsurance receivables related to paid losses.

(3) The Corporate & Other Reinsurance receivables are primarily related to A&EP claims covered under the Loss Portfolio Transfer (LPT).

Schedule of liability for unpaid claims and claims adjustment expense

The following table presents a reconciliation between beginning and ending claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves of the Life & Group segment.

As of or for the years ended December 31
(In millions)	2020		2019		2018
Reserves, beginning of year:
Gross	$	21,720	$	21,984	$	22,004
Ceded	3,835		4,019		3,934
Net reserves, beginning of year	17,885		17,965		18,070
Net incurred claim and claim adjustment expenses:
Provision for insured events of current year	5,793		5,356		5,358
Increase (decrease) in provision for insured events of prior years	(119)		(127)		(179)
Amortization of discount	183		184		176
Total net incurred (1)	5,857		5,413		5,355
Net payments attributable to:
Current year events	(948)		(992)		(1,046)
Prior year events	(4,216)		(4,584)		(4,285)
Total net payments	(5,164)		(5,576)		(5,331)
Foreign currency translation adjustment and other	123		83		(129)
Net reserves, end of year	18,701		17,885		17,965
Ceded reserves, end of year	4,005		3,835		4,019
Gross reserves, end of year	$	22,706	$	21,720	$	21,984

(1) Total net incurred above does not agree to Insurance claims and policyholders' benefits as reflected on the Consolidated Statements of Operations due to amounts related to retroactive reinsurance deferred gain accounting, uncollectible reinsurance and benefit expenses related to future policy benefits, which are not reflected in the table above.

Gross and net carried claim and claim adjustment expense reserves

The following tables present the gross and net carried reserves.

December 31, 2020	Specialty		Commercial		International		Life & Group		Corporate & Other		Total
(In millions)
Gross Case Reserves	$	1,567	$	3,724	$	892	$	3,406	$	1,105	$	10,694
Gross IBNR Reserves	4,181		5,317		1,199		337		978		12,012
Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	5,748	$	9,041	$	2,091	$	3,743	$	2,083	$	22,706
Net Case Reserves	$	1,410	$	3,357	$	777	$	3,298	$	88	$	8,930
Net IBNR Reserves	3,488		4,847		1,045		317		74		9,771
Total Net Carried Claim and Claim Adjustment Expense Reserves	$	4,898	$	8,204	$	1,822	$	3,615	$	162	$	18,701

December 31, 2019	Specialty		Commercial		International		Life & Group		Corporate & Other		Total
(In millions)
Gross Case Reserves	$	1,481	$	3,937	$	858	$	3,576	$	1,137	$	10,989
Gross IBNR Reserves	3,757		4,719		1,018		140		1,097		10,731
Total Gross Carried Claim and Claim Adjustment Expense Reserves	$	5,238	$	8,656	$	1,876	$	3,716	$	2,234	$	21,720
Net Case Reserves	$	1,343	$	3,543	$	759	$	3,441	$	92	$	9,178
Net IBNR Reserves	3,333		4,306		869		116		83		8,707
Total Net Carried Claim and Claim Adjustment Expense Reserves	$	4,676	$	7,849	$	1,628	$	3,557	$	175	$	17,885

Net prior year development

The following table presents development recorded for the Specialty, Commercial, International and Corporate & Other segments.

Years ended December 31
(In millions)	2020		2019		2018
Pretax (favorable) unfavorable development:
Specialty	$	(61)	$	(92)	$	(150)
Commercial	43		(2)		(25)
International	(2)		21		(4)
Corporate & Other	—		—		(2)
Total pretax (favorable) unfavorable development	$	(20)	$	(73)	$	(181)

Specialty

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration insurance contracts, reconciliation of claims development to liability

The table below provides the line of business composition of the net liability for unpaid claim and claim adjustment expenses for the Specialty segment.

As of December 31
(In millions)	2020
Net liability for unpaid claim and claim adjustment expenses:
Medical Professional Liability	$	1,520
Other Professional Liability and Management Liability	2,850
Surety	385
Warranty	34
Other	109
Total net liability for unpaid claim and claim adjustment expenses	$	4,898

Net prior year claim and allocated claim adjustment expense reserve development

The following table presents further detail of the development recorded for the Specialty segment.

Years ended December 31
(In millions)	2020		2019		2018
Pretax (favorable) unfavorable development:
Medical Professional Liability	$	35	$	75	$	47
Other Professional Liability and Management Liability	(15)		(69)		(127)
Surety	(69)		(92)		(70)
Warranty	(7)		(15)		(10)
Other	(5)		9		10
Total pretax (favorable) unfavorable development	$	(61)	$	(92)	$	(150)

Commercial

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration insurance contracts, reconciliation of claims development to liability

The table below provides the line of business composition of the net liability for unpaid claim and claim adjustment expenses for the Commercial segment.

As of December 31
(In millions)	2020
Net Claim and claim adjustment expenses:
Commercial Auto	$	502
General Liability	3,305
Workers' Compensation	3,872
Property and Other	525
Total net liability for claim and claim adjustment expenses	$	8,204

Net prior year claim and allocated claim adjustment expense reserve development

The following table presents further detail of the development recorded for the Commercial segment.

Years ended December 31
(In millions)	2020		2019		2018
Pretax (favorable) unfavorable development:
Commercial Auto	$	33	$	(25)	$	1
General Liability	65		54		32
Workers' Compensation	(96)		(13)		(32)
Property and Other	41		(18)		(26)
Total pretax (favorable) unfavorable development	$	43	$	(2)	$	(25)

International

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration insurance contracts, reconciliation of claims development to liability

The table below provides the composition of the net liability for unpaid claim and claim adjustment expenses for the International segment.

As of December 31
(In millions)	2020
Net Claim and claim adjustment expenses:
International excluding Hardy	$	1,282
Hardy	540
Total net liability for claim and claim adjustment expenses	$	1,822

Net prior year claim and allocated claim adjustment expense reserve development

The following table presents further detail of the development recorded for the International segment.

Years ended December 31
(In millions)	2020		2019		2018
Pretax (favorable) unfavorable development:
Casualty	$	(13)	$	(20)	$	(17)
Property, Energy and Marine(1)	13		25		—
Specialty	(2)		16		13
Total pretax (favorable) unfavorable development	$	(2)	$	21	$	(4)

(1) Effective January 1, 2020 the Property and Energy and Marine lines of business have been combined in the International segment. Prior period information has been conformed to the new line of business presentation.

CNAF Consolidated

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Schedule of historical claims duration

The table below presents information about average historical claims duration as of December 31, 2020 and is presented as required supplementary information, which is unaudited.

Average Annual Percentage Payout of Ultimate Net Incurred Claim and Allocated Claim Adjustment Expenses in Year:
	1		2		3		4		5		6		7		8		9		10
Specialty
Medical Professional Liability	3.7	%	19.5	%	24.0	%	18.4	%	12.2	%	8.2	%	5.2	%	3.1	%	0.9	%	4.1	%
Other Professional Liability and Management Liability	7.0	%	22.9	%	21.4	%	16.3	%	10.1	%	6.6	%	4.4	%	2.3	%	3.0	%	2.6	%
Surety(1)	18.3	%	44.6	%	20.0	%	3.5	%	2.2	%	1.2	%	(0.7)	%	0.9	%	(1.4)	%	—	%
Commercial
Commercial Auto	27.9	%	24.0	%	18.3	%	14.0	%	9.8	%	2.9	%	1.3	%	0.5	%	—	%	0.3	%
General Liability	4.2	%	15.0	%	18.9	%	20.3	%	14.3	%	9.1	%	5.7	%	3.2	%	2.6	%	0.3	%
Workers' Compensation	14.5	%	21.9	%	14.2	%	10.1	%	6.4	%	3.5	%	2.1	%	1.1	%	0.9	%	0.3	%
International
International - Excluding Hardy	19.8	%	25.6	%	11.0	%	7.2	%	6.2	%	5.4	%	6.9	%	2.9	%	1.1	%	0.9	%
International - Hardy (2)	22.0	%	37.5	%	12.8	%	6.3	%	4.7	%	2.4	%	1.9	%	1.4	%

(1) Due to the nature of the Surety business, average annual percentage payout of ultimate net incurred claim and allocated claim adjustment expenses has been calculated using only the payouts of mature accident years presented in the loss reserve development tables.

(2) Average historical claims duration for Hardy is presented prospectively beginning with the first full year subsequent to acquisition, 2013.

Impact of loss portfolio transfer on the consolidated statement of operations

The following table presents the impact of the Loss Portfolio Transfer on the Consolidated Statements of Operations.

Years ended December 31
(In millions)	2020		2019		2018
Additional amounts ceded under LPT:
Net A&EP adverse development before consideration of LPT	$	125	$	150	$	178
Provision for uncollectible third-party reinsurance on A&EP	(25)		(25)		(16)
Total additional amounts ceded under LPT	100		125		162
Retroactive reinsurance benefit recognized	(94)		(107)		(114)
Pretax impact of deferred retroactive reinsurance	$	6	$	18	$	48

Hardy | International

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31							Calendar Year																As of December 31, 2020
(In millions, except reported claims data)	Net Claim and Allocated Claim Adjustment Expense Reserves at Acquisition		Net Incurred Claim and Allocated Claim Adjustment Expenses in 2012(1)(2)		Total Acquired Net Claim and Allocated Claim Adjustment Expense Reserves and 2012 Incurreds		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020			IBNR		Cumulative Number of Claims
Accident Year
2011	$	130	$	(2)	$	128	$	140	$	139	$	144	$	143	$	144	$	146	$	146	$	147		$	(1)	6,307
2012	34		72		106		106		114		122		115		116		118		117		115			(1)		6,970
2013							133		149		140		142		143		147		147		147			2		7,744
2014									188		186		180		173		174		175		173			—		8,302
2015											194		183		181		182		181		182			(5)		9,401
2016													233		252		240		228		230			12		10,369
2017															248		258		246		247			5		12,430
2018																	278		310		314			44		14,076
2019																			226		229			76		9,648
2020																					216			143		4,081
																			Total		$	2,000		$	275

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2012(1)(2)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	31	$	86	$	128	$	133	$	136	$	138	$	140	$	141	$	142
2012	15		81		102		111		109		112		113		113		115
2013			39		103		123		129		133		136		140		142
2014					57		125		143		153		159		164		166
2015							30		99		132		147		160		164
2016									64		148		175		185		198
2017											54		152		186		208
2018													56		179		207
2019															44		104
2020																	28
Total																	$	1,474
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																	$	526
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																	5
Liability for unallocated claim adjustment expenses for accident years presented																	9
Total net liability for unpaid claim and claim adjustment expenses																	$	540

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)(2)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total(3)
Accident Year
2011	$	(2)	$	12	$	(1)	$	5	$	(1)	$	1	$	2	$	—	$	1	$	17
2012			—		8		8		(7)		1		2		(1)		(2)		9
2013					16		(9)		2		1		4		—		—		14
2014							(2)		(6)		(7)		1		1		(2)		(15)
2015									(11)		(2)		1		(1)		1		(12)
2016											19		(12)		(12)		2		(3)
2017													10		(12)		1		(1)
2018															32		4		36
2019																	3		3

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

(2) Data presented for this calendar year is post-acquisition of Hardy.

(3) The amounts included in the loss reserve development tables above are presented at the year-end 2020 foreign currency exchange rates for all periods presented to remove the effects of foreign currency exchange rate fluctuations between calendar years. The amounts included within the table on page 101 presenting the detail of the development recorded within the International segment include the impact of fluctuations in foreign currency exchange rates.

Medical Professional Liability | Specialty

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year																				As of December 31, 2020
(In millions, except reported claims data)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		IBNR		Cumulative Number of Claims
Accident Year
2011	$	429	$	437	$	443	$	468	$	439	$	434	$	437	$	437	$	439	$	439	$	4	16,537
2012			464		469		508		498		493		484		493		499		497		5		17,739
2013					462		479		500		513		525		535		545		531		11		19,537
2014							450		489		537		530		535		529		527		11		19,770
2015									433		499		510		494		488		510		29		18,122
2016											427		487		485		499		508		27		15,998
2017													412		449		458		460		62		15,008
2018															404		429		431		98		14,531
2019																	430		445		232		13,045
2020																			477		426		7,787
																	Total		$	4,825	$	905

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	17	$	109	$	208	$	295	$	347	$	375	$	398	$	409	$	414	$	432
2012			14		117		221		323		388		427		457		479		482
2013					17		119		255		355		414		462		495		508
2014							23		136		258		359		417		472		489
2015									22		101		230		313		384		420
2016											18		121		246		339		401
2017													19		107		235		308
2018															21		115		211
2019																	17		91
2020																			11
																	Total		$	3,353
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																			$	1,472
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																			19
Liability for unallocated claim adjustment expenses for accident years presented																			29
Total net liability for unpaid claim and claim adjustment expenses																			$	1,520

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total
Accident Year
2011	$	8	$	6	$	25	$	(29)	$	(5)	$	3	$	—	$	2	$	—	$	10
2012			5		39		(10)		(5)		(9)		9		6		(2)		33
2013					17		21		13		12		10		10		(14)		69
2014							39		48		(7)		5		(6)		(2)		77
2015									66		11		(16)		(6)		22		77
2016											60		(2)		14		9		81
2017													37		9		2		48
2018															25		2		27
2019																	15		15
Total net development for the accident years presented above													43		54		32
Total net development for accident years prior to 2011													5		19		3
Total unallocated claim adjustment expense development													(1)		2		—
Total													$	47	$	75	$	35

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

Other Professional Liability and Management Liability | Specialty

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year																				As of December 31, 2020
(In millions, except reported claims data)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		IBNR		Cumulative Number of Claims
Accident Year
2011	$	880	$	908	$	934	$	949	$	944	$	911	$	899	$	888	$	885	$	883	$	17	18,745
2012			923		909		887		878		840		846		833		831		850		25		18,504
2013					884		894		926		885		866		863		850		846		36		17,939
2014							878		898		885		831		835		854		845		57		17,568
2015									888		892		877		832		807		813		74		17,417
2016											901		900		900		904		907		120		17,946
2017													847		845		813		791		220		18,118
2018															850		864		869		276		19,789
2019																	837		845		447		19,157
2020																			930		777		16,557
																	Total		$	8,579	$	2,049

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	71	$	314	$	503	$	605	$	683	$	726	$	781	$	796	$	828	$	851
2012			56		248		400		573		651		711		755		792		812
2013					54		249		447		618		702		754		771		779
2014							51		223		392		515		647		707		743
2015									60		234		404		542		612		677
2016											64		248		466		625		701
2017													57		222		394		498
2018															54		282		473
2019																	64		263
2020																			67
																	Total		$	5,864
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																			$	2,715
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																			79
Liability for unallocated claim adjustment expenses for accident years presented																			56
Total net liability for unpaid claim and claim adjustment expenses																			$	2,850

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total
Accident Year
2011	$	28	$	26	$	15	$	(5)	$	(33)	$	(12)	$	(11)	$	(3)	$	(2)	$	3
2012			(14)		(22)		(9)		(38)		6		(13)		(2)		19		(73)
2013					10		32		(41)		(19)		(3)		(13)		(4)		(38)
2014							20		(13)		(54)		4		19		(9)		(33)
2015									4		(15)		(45)		(25)		6		(75)
2016											(1)		—		4		3		6
2017													(2)		(32)		(22)		(56)
2018															14		5		19
2019																	8		8
Total net development for the accident years presented above													(70)		(38)		4
Total net development for accident years prior to 2011													(50)		(17)		(19)
Total unallocated claim adjustment expense development													(7)		(14)		—
Total													$	(127)	$	(69)	$	(15)

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

Surety | Specialty

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year																				As of December 31, 2020
(In millions, except reported claims data)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		IBNR		Cumulative Number of Claims
Accident Year
2011	$	120	$	121	$	116	$	87	$	75	$	70	$	66	$	62	$	62	$	62	$	1	5,828
2012			120		122		98		70		52		45		39		38		37		1		5,577
2013					120		121		115		106		91		87		83		82		1		5,078
2014							123		124		94		69		60		45		45		1		5,102
2015									131		131		104		79		63		58		6		5,026
2016											124		124		109		84		67		12		5,469
2017													120		115		103		84		31		5,706
2018															114		108		91		48		5,920
2019																	119		112		67		5,344
2020																			128		122		2,527
																	Total		$	766	$	290

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	19	$	42	$	55	$	58	$	60	$	60	$	56	$	57	$	57	$	57
2012			5		32		34		35		35		36		37		37		36
2013					16		40		69		78		78		78		77		78
2014							7		30		38		36		38		38		39
2015									7		26		38		40		42		44
2016											5		37		45		45		43
2017													23		37		41		46
2018															5		25		34
2019																	12		34
2020																			4
																	Total		$	415
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																			$	351
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																			14
Liability for unallocated claim adjustment expenses for accident years presented																			20
Total net liability for unpaid claim and claim adjustment expenses																			$	385

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total
Accident Year
2011	$	1	$	(5)	$	(29)	$	(12)	$	(5)	$	(4)	$	(4)	$	—	$	—	$	(58)
2012			2		(24)		(28)		(18)		(7)		(6)		(1)		(1)		(83)
2013					1		(6)		(9)		(15)		(4)		(4)		(1)		(38)
2014							1		(30)		(25)		(9)		(15)		—		(78)
2015									—		(27)		(25)		(16)		(5)		(73)
2016											—		(15)		(25)		(17)		(57)
2017													(5)		(12)		(19)		(36)
2018															(6)		(17)		(23)
2019																	(7)		(7)
Total net development for the accident years presented above													(68)		(79)		(67)
Total net development for accident years prior to 2011													(2)		(3)		(2)
Total unallocated claim adjustment expense development													—		(10)		—
Total													$	(70)	$	(92)	$	(69)

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

Commercial Auto | Commercial

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year																				As of December 31, 2020
(In millions, except reported claims data)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		IBNR		Cumulative Number of Claims
Accident Year
2011	$	268	$	281	$	288	$	302	$	300	$	294	$	294	$	294	$	291	$	292	$	—	47,907
2012			275		289		299		303		307		299		299		297		296		2		46,288
2013					246		265		265		249		245		245		241		241		2		39,429
2014							234		223		212		205		205		201		201		1		33,625
2015									201		199		190		190		183		181		3		30,426
2016											198		186		186		186		190		2		30,430
2017													199		198		200		221		7		30,913
2018															229		227		227		10		34,225
2019																	257		266		48		36,779
2020																			310		187		24,427
																	Total		$	2,425	$	262

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	79	$	145	$	199	$	248	$	274	$	284	$	287	$	289	$	289	$	290
2012			78		160		220		259		282		285		290		291		291
2013					74		135		168		200		225		234		238		239
2014							64		102		137		166		187		196		198
2015									52		96		130		153		172		175
2016											52		93		126		154		175
2017													58		107		150		178
2018															66		128		175
2019																	77		147
2020																			71
																	Total		$	1,939
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																			$	486
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																			2
Liability for unallocated claim adjustment expenses for accident years presented																			14
Total net liability for unpaid claim and claim adjustment expenses																			$	502

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total
Accident Year
2011	$	13	$	7	$	14	$	(2)	$	(6)	$	—	$	—	$	(3)	$	1	$	24
2012			14		10		4		4		(8)		—		(2)		(1)		21
2013					19		—		(16)		(4)		—		(4)		—		(5)
2014							(11)		(11)		(7)		—		(4)		—		(33)
2015									(2)		(9)		—		(7)		(2)		(20)
2016											(12)		—		—		4		(8)
2017													(1)		2		21		22
2018															(2)		—		(2)
2019																	9		9
Total net development for the accident years presented above													(1)		(20)		32
Total net development for accident years prior to 2011													1		(4)		1
Total unallocated claim adjustment expense development													1		(1)		—
Total													$	1	$	(25)	$	33

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

General Liability | Commercial

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year																				As of December 31, 2020
(In millions, except reported claims data)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		IBNR		Cumulative Number of Claims
Accident Year
2011	$	591	$	589	$	631	$	677	$	676	$	681	$	670	$	669	$	667	$	667	$	21	39,405
2012			587		611		639		636		619		635		635		630		632		24		35,276
2013					650		655		650		655		613		623		620		623		27		33,649
2014							653		658		654		631		635		658		659		44		27,972
2015									581		576		574		589		600		602		38		24,005
2016											623		659		667		671		673		104		24,215
2017													632		632		632		634		136		21,781
2018															653		644		646		302		19,234
2019																	680		682		453		17,294
2020																			723		640		9,593
																	Total		$	6,541	$	1,789

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	28	$	148	$	273	$	411	$	517	$	568	$	602	$	622	$	638	$	640
2012			28		132		247		374		454		510		559		579		597
2013					31		128		240		352		450		510		551		572
2014							31		119		247		376		481		547		569
2015									19		110		230		357		446		501
2016											32		163		279		407		481
2017													23		118		250		399
2018															33		107		228
2019																	25		98
2020																			23
																	Total		$	4,108
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																			$	2,433
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																			812
Liability for unallocated claim adjustment expenses for accident years presented																			60
Total net liability for unpaid claim and claim adjustment expenses																			$	3,305

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total
Accident Year
2011	$	(2)	$	42	$	46	$	(1)	$	5	$	(11)	$	(1)	$	(2)	$	—	$	76
2012			24		28		(3)		(17)		16		—		(5)		2		45
2013					5		(5)		5		(42)		10		(3)		3		(27)
2014							5		(4)		(23)		4		23		1		6
2015									(5)		(2)		15		11		2		21
2016											36		8		4		2		50
2017													—		—		2		2
2018															(9)		2		(7)
2019																	2		2
Total net development for the accident years presented above													36		19		16
Total net development for accident years prior to 2011													—		28		49
Total unallocated claim adjustment expense development													(4)		7		—
Total													$	32	$	54	$	65

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

Workers' Compensation | Commercial

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year																				As of December 31, 2020
(In millions, except reported claims data)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		IBNR		Cumulative Number of Claims
Accident Year
2011	$	607	$	641	$	647	$	659	$	651	$	676	$	676	$	674	$	688	$	698	$	42	46,443
2012			601		627		659		669		678		673		671		668		663		62		42,685
2013					537		572		592		618		593		582		561		552		92		38,758
2014							467		480		479		452		450		446		439		97		33,488
2015									422		431		406		408		394		382		116		31,876
2016											426		405		396		382		366		121		31,967
2017													440		432		421		400		97		33,094
2018															450		440		428		129		34,800
2019																	452		449		181		34,020
2020																			477		312		24,980
																	Total		$	4,854	$	1,249

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	99	$	249	$	358	$	438	$	478	$	522	$	564	$	571	$	581	$	583
2012			87		232		342		416		470		509		524		536		538
2013					80		213		300		370		417		419		411		414
2014							61		159		215		258		282		290		297
2015									51		131		180		212		231		243
2016											53		129		169		198		219
2017													63		151		207		243
2018															68		163		229
2019																	71		169
2020																			65
																	Total		$	3,000
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																			$	1,854
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																			1,984
Other (2)																			(15)
Liability for unallocated claim adjustment expenses for accident years presented																			49
Total net liability for unpaid claim and claim adjustment expenses																			$	3,872

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total
Accident Year
2011	$	34	$	6	$	12	$	(8)	$	25	$	—	$	(2)	$	14	$	10	$	91
2012			26		32		10		9		(5)		(2)		(3)		(5)		62
2013					35		20		26		(25)		(11)		(21)		(9)		15
2014							13		(1)		(27)		(2)		(4)		(7)		(28)
2015									9		(25)		2		(14)		(12)		(40)
2016											(21)		(9)		(14)		(16)		(60)
2017													(8)		(11)		(21)		(40)
2018															(10)		(12)		(22)
2019																	(3)		(3)
Total net development for the accident years presented above													(32)		(63)		(75)
Adjustment for development on a discounted basis													—		3		2
Total net development for accident years prior to 2011													7		24		(23)
Total unallocated claim adjustment expense development													(7)		23		—
Total													$	(32)	$	(13)	$	(96)

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

(2) Other includes the effect of discounting lifetime claim reserves.

Excluding Hardy | International

Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]

Short-duration contracts net incurred claims and allocated claim adjustment expenses

Cumulative Net Incurred Claim and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year																				As of December 31, 2020
(In millions, except reported claims data)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		IBNR		Cumulative Number of Claims
Accident Year
2011	$	282	$	283	$	275	$	254	$	242	$	235	$	233	$	230	$	223	$	221	$	(1)	24,526
2012			283		290		275		267		267		259		252		246		242		12		24,901
2013					305		307		299		278		274		265		256		252		10		23,808
2014							293		309		309		296		288		306		308		21		24,601
2015									307		324		322		304		298		301		35		22,675
2016											302		322		307		304		294		37		15,363
2017													318		385		407		399		99		16,086
2018															393		411		416		105		20,423
2019																	365		379		124		16,890
2020																			406		272		10,498
																	Total		$	3,218	$	714

Short-duration contracts net cumulative paid claim adjustment expenses reconciliation of total liability for unpaid claim and claim adjustment expense

Cumulative Net Paid Claims and Allocated Claim Adjustment Expenses are presented in the following table.

As of December 31	Calendar Year
(In millions)	2011(1)		2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020
Accident Year
2011	$	47	$	121	$	144	$	158	$	172	$	184	$	193	$	197	$	200	$	202
2012			46		119		153		175		191		204		214		218		220
2013					52		118		147		164		179		190		209		222
2014							54		128		157		175		193		214		250
2015									59		139		171		192		216		231
2016											70		139		167		191		204
2017													67		154		196		226
2018															96		177		226
2019																	77		173
2020																			63
Total																			$	2,017
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented																			$	1,201
Net liability for unpaid claim and claim adjustment expenses for accident years prior to 2011																			47
Liability for unallocated claim adjustment expenses for accident years presented																			34
Total net liability for unpaid claim and claim adjustment expenses																			$	1,282

Short-duration contracts reserve development

Net strengthening (releases) of prior accident year reserves is presented in the following table.

For the years ended December 31	Calendar Year
(In millions)	2012(1)		2013(1)		2014(1)		2015(1)		2016(1)		2017(1)		2018(1)		2019(1)		2020		Total (2)
Accident Year
2011	$	1	$	(8)	$	(21)	$	(12)	$	(7)	$	(2)	$	(3)	$	(7)	$	(2)	$	(61)
2012			7		(15)		(8)		—		(8)		(7)		(6)		(4)		(41)
2013					2		(8)		(21)		(4)		(9)		(9)		(4)		(53)
2014							16		—		(13)		(8)		18		2		15
2015									17		(2)		(18)		(6)		3		(6)
2016											20		(15)		(3)		(10)		(8)
2017													67		22		(8)		81
2018															18		5		23
2019																	14		14

(1) Data presented for these calendar years is required supplemental information, which is unaudited.

(2) The amounts included in the loss reserve development tables above are presented at the year-end 2020 foreign currency exchange rates for all periods presented to remove the effects of foreign currency exchange rate fluctuations between calendar years. The amounts included within the table on page 101 presenting the detail of the development recorded within the International segment include the impact of fluctuations in foreign currency exchange rates.