
($ in thousands)	2020		2019	2018
Gross reserves for loss and loss expense, at beginning of year	$	4,067,163	3,893,868	3,771,240
Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year1	547,066		537,388	585,855
Net reserves for loss and loss expense, at beginning of year	3,520,097		3,356,480	3,185,385
Incurred loss and loss expense for claims occurring in the:
Current year	1,708,755		1,601,780	1,527,997
Prior years	(72,932)		(50,289)	(29,863)
Total incurred loss and loss expense	1,635,823		1,551,491	1,498,134
Paid loss and loss expense for claims occurring in the:
Current year	642,586		579,527	573,718
Prior years	807,248		805,443	753,321
Total paid loss and loss expense	1,449,834		1,384,970	1,327,039
Net reserves for loss and loss expense, at end of year	3,706,086		3,523,001	3,356,480
Add: Reinsurance recoverable on unpaid loss and loss expense, at end of year	554,269		544,162	537,388
Gross reserves for loss and loss expense at end of year	$	4,260,355	4,067,163	3,893,868

Our net loss and loss expense reserves increased by $183.1 million in 2020, $166.5 million in 2019, and $171.1 million in 2018. The loss and loss expense reserves are net of anticipated recoveries for salvage and subrogation claims, which amounted to $80.9 million for 2020, $76.7 million for 2019, and $67.7 million for 2018. The increase in net loss and loss expense reserves in 2020 was primarily driven by increases in exposure due to premium growth.


(Favorable)/Unfavorable Prior Year Development
($ in millions)	2020		2019	2018
General Liability	$	(35.0)	(5.0)	(9.5)
Commercial Automobile	7.1		0.7	36.7
Workers Compensation	(60.0)		(68.0)	(83.0)
Businessowners' Policies	3.9		1.9	(1.5)
Commercial Property	9.2		5.1	7.5
Homeowners	7.7		7.5	9.8
Personal Automobile	(1.8)		4.4	3.0
E&S Casualty Lines	—		2.0	12.0
E&S Property Lines	(4.0)		1.0	(4.8)
Other	—		0.1	(0.1)
Total	$	(72.9)	(50.3)	(29.9)

The Insurance Subsidiaries had $72.9 million of favorable prior accident year reserve development during 2020, which included $85.0 million of net favorable casualty reserve development and $12.1 million of unfavorable property reserve development. The net favorable casualty reserve development was largely driven by the workers compensation and general liability lines of business. Workers compensation was impacted by continued favorable medical trends in accident years 2018 and prior, and general liability development was attributable to lower loss severities in accident years 2017 and prior. Partially offsetting this net favorable reserve development was $10 million of unfavorable casualty reserve development in the commercial auto line of business ($7.1 million net of property reserve development), driven by unfavorable reserve development on loss severities in accident years 2016 through 2019, and higher than expected frequencies in accident year 2019.

The Insurance Subsidiaries had $50.3 million of favorable prior accident year reserve development during 2019, which included $61.0 million of net favorable casualty reserve development and $10.7 million of unfavorable property reserve development. The net favorable casualty reserve development was largely driven by the workers compensation line of business, reflecting continued favorable medical trends in accident years 2017 and prior.

The Insurance Subsidiaries had $29.9 million of favorable prior accident year reserve development during 2018, which included $41.5 million of net favorable casualty reserve development and $11.6 million of unfavorable property reserve development. The net favorable casualty reserve development was largely driven by the workers compensation line of business, reflecting continued favorable medical trends in accident years 2017 and prior. Partially offsetting this net favorable reserve development was $37.5 million of unfavorable casualty reserve development in the commercial automobile line of business, driven by increases in frequencies and severities in accident years 2015 through 2017. In addition, our E&S casualty lines experienced unfavorable reserve development of $12.0 million in 2018.

(b) We have exposure to abuse or molestation claims within our general liability line of business through insurance policies that we issue to schools, religious institutions, daycares, and other social services. We also have exposure to abuse or molestation claims from recently enacted state laws that extend the statute of limitations or permit windows to be opened for abuse or molestation claims and lawsuits that were previously barred by statutes of limitations. The emergence of these claims is slow and highly unpredictable. There are significant uncertainties in estimating our exposure to abuse or molestation claims (for both case and IBNR reserves) resulting from (i) lack of relevant historical data, (ii) the delayed and inconsistent reporting patterns associated with these claims, (iii) the obligation of an insurer to defend a claim, (iv) the extent to which a party can prove the existence of coverage, and (v) uncertainty as to the number and identity of claimants. It is possible, as a result, that we may receive claims decades after the allegations occurred from coverages provided by us, including predecessor companies, that will require complex claims coverage determinations, potential litigation, and the need to collect from reinsurers under older reinsurance agreements. We do not discount to present value that portion of our loss and loss expense reserves expected to be paid in future periods.

(c) Reserves established for liability insurance include exposure to asbestos and environmental claims. These claims have arisen primarily from insured exposures in municipal government, small non-manufacturing commercial risk, and homeowners policies. The emergence of these claims is slow and highly unpredictable. There are significant uncertainties in estimating our exposure to asbestos and environmental claims (for both case and IBNR reserves) resulting from (i) lack of relevant historical data, (ii) the delayed and inconsistent reporting patterns associated with these claims, and (iii) uncertainty as to the number and identity of claimants and complex legal and coverage issues. Legal issues that arise in asbestos and environmental cases include federal or state venue, choice of law, causation, admissibility of evidence, allocation of damages and contribution among joint defendants, successor and predecessor liability, and whether direct action against insurers can be maintained.

Coverage issues that arise in asbestos and environmental cases include the interpretation and application of policy exclusions, the determination and calculation of policy limits, the determination of the ultimate amount of a loss, the extent to which a loss is covered by a policy, if at all, the obligation of an insurer to defend a claim, and the extent to which a party can prove the existence of coverage. Courts have reached different and sometimes inconsistent conclusions on these legal and coverage issues.

Traditional accident year loss development methods cannot be applied because past loss history is not necessarily indicative of future behavior. Instead, we review the experience by calendar year and rely on alternative metrics, such as paid and incurred survival ratios. As a result, reserves for asbestos and environmental require a high degree of judgment. Because of the significant uncertainty in the estimate, we do not calculate an asbestos and environmental loss range.

Historically, our asbestos and environmental claims have been significantly lower in volume than many other standard commercial lines carriers since, prior to the introduction of the absolute pollution exclusion endorsement in the mid-1980’s, we primarily wrote Standard Personal Lines, and therefore, our exposure to asbestos and environmental claims has been limited.


	2020			2019		2018
($ in thousands)	Gross		Net	Gross	Net	Gross	Net
Asbestos
Reserves for loss and loss expense at beginning of year	$	6,288	5,057	7,328	6,097	7,577	6,346
Incurred loss and loss expense	320		320	(375)	(375)	—	—
Less: loss and loss expense paid	(354)		(354)	(665)	(665)	(249)	(249)
Reserves for loss and loss expense at the end of year	$	6,254	5,023	6,288	5,057	7,328	6,097

Environmental
Reserves for loss and loss expense at beginning of year	$	22,413	16,532	22,692	16,686	20,838	14,866
Incurred loss and loss expense	(447)		(474)	723	609	3,059	2,877
Less: loss and loss expense paid	310		340	(1,002)	(763)	(1,205)	(1,057)
Reserves for loss and loss expense at the end of year	$	22,276	16,398	22,413	16,532	22,692	16,686

Total Asbestos and Environmental Claims
Reserves for loss and loss expense at beginning of year	$	28,701	21,589	30,020	22,783	28,415	21,212
Incurred loss and loss expense	(127)		(154)	348	234	3,059	2,877
Less: loss and loss expense paid	(44)		(14)	(1,667)	(1,428)	(1,454)	(1,306)
Reserves for loss and loss expense at the end of year	$	28,530	21,421	28,701	21,589	30,020	22,783

(d) The following is information about incurred and paid claims development as of December 31, 2020, net of reinsurance, as well as cumulative claim frequency and the associated IBNR liabilities. During the experience period, we implemented a series of underwriting and claims-related initiatives, as well as, claims management changes. These initiatives focused on exiting underperforming books of business, claims handling and reserving, medical claims costs, and loss expenses. As a result of these initiatives, several historical patterns have changed and may no longer be appropriate to use as the sole basis for projections.


All Lines (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	1,042,576	1,061,667	1,062,233	1,056,107	1,033,518	1,023,726	1,019,351	1,013,115	1,013,175	1,009,162	36,641	105,039
2012			1,065,437	1,071,290	1,020,655	998,028	973,089	973,644	973,411	968,536	962,091	41,426	104,343
2013				1,044,142	1,062,045	1,047,230	1,021,007	1,002,316	987,763	984,858	973,739	57,866	91,539
2014					1,107,513	1,133,798	1,146,990	1,124,014	1,104,218	1,100,208	1,089,529	60,028	95,366
2015						1,114,081	1,130,513	1,144,830	1,138,313	1,119,441	1,108,860	77,855	94,594
2016							1,188,608	1,203,634	1,227,142	1,199,734	1,180,829	126,935	95,203
2017								1,270,110	1,313,372	1,313,585	1,288,526	206,627	98,918
2018									1,413,800	1,461,603	1,457,415	342,256	105,772
2019										1,483,945	1,523,041	539,113	101,631
2020											1,591,972	820,762	85,549
										Total	12,185,164


All Lines (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	391,944	585,867	692,730	782,655	852,202	901,801	924,111	940,626	950,836	957,391
2012			378,067	555,819	651,544	743,742	810,135	856,195	879,372	898,269	905,816
2013				335,956	518,872	644,475	748,758	833,823	872,331	891,841	904,825
2014					405,898	614,075	736,154	855,959	936,425	981,868	1,002,157
2015						376,641	581,203	725,385	845,868	929,222	967,857
2016							387,272	617,958	764,331	892,390	983,852
2017								433,440	678,453	829,134	954,792
2018									511,271	779,466	942,893
2019										510,091	781,462
2020											572,302
										Total	8,973,347
						All outstanding liabilities before 2011, net of reinsurance					364,395
					Liabilities for loss and loss expenses, net of reinsurance						3,576,212


General Liability (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	227,769	228,720	239,480	230,785	217,256	211,196	212,011	211,500	213,485	209,846	13,501	11,691
2012			238,979	245,561	215,083	194,144	175,305	175,268	180,659	182,085	178,285	15,055	10,034
2013				250,609	251,421	239,776	225,709	210,785	203,831	202,697	195,697	19,110	10,397
2014					244,312	249,946	257,132	239,333	234,082	237,125	229,679	29,018	10,652
2015						254,720	245,710	246,990	233,249	219,204	214,176	38,182	10,537
2016							277,214	272,048	277,986	263,245	252,733	61,329	10,753
2017								293,747	293,128	301,384	289,883	114,160	11,096
2018									317,934	336,326	345,224	182,931	11,350
2019										347,150	356,363	248,289	10,531
2020											361,554	311,657	6,990
										Total	2,633,440


General Liability (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	13,924	42,692	73,643	102,978	135,377	159,768	170,525	181,856	187,276	190,650
2012			13,030	35,241	56,580	89,008	109,448	130,866	144,451	156,186	158,397
2013				12,789	35,113	72,127	104,587	139,114	153,628	163,764	169,847
2014					14,901	46,825	79,972	121,969	154,957	179,192	187,352
2015						14,665	39,978	78,668	116,804	144,216	157,071
2016							15,684	46,549	89,431	133,757	164,136
2017								17,366	49,470	92,355	131,980
2018									19,531	60,784	108,421
2019										18,097	58,284
2020											21,858
										Total	1,347,996
						All outstanding liabilities before 2011, net of reinsurance					95,458
					Liabilities for loss and loss expenses, net of reinsurance						1,380,902


Workers Compensation (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	205,238	218,973	214,743	215,114	210,591	205,708	200,674	194,821	192,863	191,875	21,900	11,863
2012			203,864	208,036	199,360	195,197	188,596	187,359	183,314	178,774	177,658	23,181	11,624
2013				199,794	194,318	187,658	173,160	166,662	162,787	159,767	157,645	23,321	11,382
2014					199,346	187,065	182,579	172,515	164,420	160,646	159,604	25,582	10,495
2015						193,729	194,639	183,604	179,642	176,242	172,572	22,368	10,551
2016							196,774	184,946	176,248	166,009	156,540	29,220	10,582
2017								195,202	184,306	175,853	162,672	34,474	10,808
2018									193,894	193,818	181,151	48,883	11,111
2019										188,625	188,596	69,909	10,267
2020											168,643	97,510	7,017
										Total	1,716,956


Workers Compensation (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	42,941	90,836	118,847	134,646	139,232	149,269	154,320	158,535	161,696	163,554
2012			40,911	86,909	108,211	122,755	132,052	139,477	143,281	146,739	148,750
2013				36,829	74,568	96,376	109,739	118,669	124,130	126,822	129,224
2014					35,924	78,944	100,876	113,626	119,392	124,077	127,858
2015						33,857	77,320	98,195	112,601	120,097	124,046
2016							34,525	78,531	98,037	109,166	115,159
2017								40,375	82,216	100,645	110,645
2018									41,122	84,780	105,903
2019										37,826	77,878
2020											29,559
										Total	1,132,576
						All outstanding liabilities before 2011, net of reinsurance					243,766
					Liabilities for loss and loss expenses, net of reinsurance						828,146


Commercial Automobile (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	174,006	183,044	182,325	178,421	172,617	174,882	174,514	173,507	173,401	172,684	205	25,651
2012			179,551	191,947	183,527	184,289	184,367	186,128	184,633	185,357	184,477	811	24,295
2013				188,289	205,282	209,197	207,994	210,410	207,975	209,602	208,040	1,694	25,886
2014					200,534	212,725	216,824	219,925	218,172	217,334	216,461	2,096	27,896
2015						220,994	240,958	253,074	259,495	260,565	261,386	2,729	29,590
2016							255,187	274,367	285,302	285,304	290,359	8,469	31,465
2017								301,274	329,389	324,291	322,197	22,447	32,775
2018									347,908	352,487	345,547	47,298	35,418
2019										385,212	398,346	111,327	35,703
2020											381,654	195,279	28,366
										Total	2,781,151


Commercial Automobile (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	69,849	99,196	121,576	142,507	157,291	166,082	170,000	170,913	172,365	172,413
2012			73,316	105,371	127,235	148,669	168,114	176,656	179,501	181,353	183,098
2013				76,469	109,893	140,015	169,850	189,626	200,750	202,622	205,064
2014					80,810	117,169	148,884	180,701	202,821	209,655	212,481
2015						91,347	132,260	175,866	211,515	238,142	249,905
2016							106,022	155,720	200,701	233,939	264,858
2017								117,287	178,823	220,422	262,349
2018									134,867	193,788	243,713
2019										149,538	221,590
2020											139,016
										Total	2,154,487
						All outstanding liabilities before 2011, net of reinsurance					3,848
					Liabilities for loss and loss expenses, net of reinsurance						630,512


Businessowners' Policies (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	54,469	57,083	51,047	58,242	59,256	58,966	58,456	58,735	58,948	58,697	516	4,961
2012			54,342	48,029	46,303	44,172	44,077	43,747	43,418	43,717	43,444	117	5,545
2013				49,617	42,618	41,005	40,624	41,369	39,709	39,699	39,358	554	3,483
2014					55,962	60,949	62,548	59,806	58,517	58,093	57,302	616	4,066
2015						52,871	53,768	57,245	55,925	54,454	52,325	1,178	3,963
2016							52,335	53,792	54,993	53,835	53,367	1,877	3,847
2017								46,624	48,698	51,524	48,067	5,981	3,885
2018									55,024	57,202	62,427	12,432	4,229
2019										53,531	59,466	12,872	3,541
2020											71,836	17,392	5,019
										Total	546,289


Businessowners' Policies (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	27,884	37,362	41,011	46,444	52,114	55,856	57,045	57,365	57,380	57,385
2012			22,199	31,833	35,089	37,215	38,766	40,627	41,326	41,356	42,075
2013				17,412	26,592	30,845	34,760	37,993	38,464	39,085	39,212
2014					28,914	40,584	44,911	49,460	52,940	55,458	55,708
2015						24,189	36,014	42,710	46,571	49,073	49,839
2016							24,655	36,848	39,973	45,308	48,786
2017								21,865	31,337	36,950	40,359
2018									29,995	39,791	44,316
2019										27,718	41,587
2020											43,376
										Total	462,643
						All outstanding liabilities before 2011, net of reinsurance					7,773
					Liabilities for loss and loss expenses, net of reinsurance						91,419


Commercial Property (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	136,954	131,667	130,942	131,282	131,353	131,113	131,049	131,009	131,002	130,994	9	9,038
2012			118,464	114,224	115,375	116,658	117,102	117,170	117,225	117,220	117,200	6	8,517
2013				88,101	90,639	90,103	90,005	90,436	90,278	90,218	90,486	11	5,715
2014					141,192	136,249	136,820	138,751	138,155	136,212	136,237	13	6,516
2015						110,270	109,513	111,750	111,566	112,496	112,582	24	6,406
2016							121,927	126,185	125,937	124,487	123,567	60	6,741
2017								138,773	149,106	149,044	153,664	(289)	6,900
2018									183,177	190,834	192,558	(841)	8,280
2019										173,826	177,075	(738)	7,262
2020											232,060	37,050	9,494
										Total	1,466,423


Commercial Property (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	94,538	127,580	129,579	130,681	131,060	131,115	131,089	131,100	131,092	131,083
2012			81,528	108,834	111,503	114,699	116,291	116,625	116,671	116,674	116,673
2013				60,244	87,874	90,446	90,350	90,840	90,696	90,646	90,917
2014					101,131	132,909	136,634	137,883	137,418	136,008	135,928
2015						79,048	106,182	109,829	110,994	110,969	112,117
2016							83,966	118,789	122,930	123,828	123,601
2017								99,047	142,338	148,589	152,018
2018									135,416	184,813	192,698
2019										130,891	172,768
2020											164,613
										Total	1,392,416
						All outstanding liabilities before 2011, net of reinsurance					175
					Liabilities for loss and loss expenses, net of reinsurance						74,182


Personal Automobile (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	113,232	116,164	113,686	112,993	114,241	113,830	113,988	113,921	114,056	114,038	31	22,700
2012			113,771	114,921	109,832	109,324	110,294	110,300	109,795	109,701	109,634	78	22,333
2013				108,417	109,620	106,225	106,703	107,759	107,680	107,916	107,803	121	22,376
2014					102,250	109,325	106,757	107,452	106,821	107,104	107,106	(42)	22,508
2015						96,387	99,698	100,214	99,570	98,718	98,588	295	20,865
2016							92,727	98,032	100,202	101,140	99,544	452	19,824
2017								101,880	105,139	103,653	103,260	1,607	20,739
2018									111,594	113,569	112,030	5,597	22,668
2019										114,043	115,688	13,260	22,804
2020											95,625	30,333	16,309
										Total	1,063,316


Personal Automobile (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	61,323	82,102	93,878	105,068	111,085	112,732	113,551	113,664	113,856	113,996
2012			63,704	82,729	94,842	102,977	107,890	109,355	109,447	109,482	109,554
2013				61,384	80,861	92,637	100,528	105,131	106,679	106,876	107,419
2014					62,519	83,739	92,589	99,173	104,055	105,709	106,478
2015						58,725	76,470	87,163	92,102	95,997	97,275
2016							57,961	76,823	86,752	94,372	98,080
2017								62,854	82,730	91,479	97,628
2018									69,721	89,628	99,982
2019										69,699	92,162
2020											53,407
										Total	975,981
						All outstanding liabilities before 2011, net of reinsurance					6,902
					Liabilities for loss and loss expenses, net of reinsurance						94,237


Homeowners (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance												As of December 31, 2020
Accident Year	Unaudited											IBNR	Cumulative Number of Reported Claims
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	103,804	98,211	97,761	94,167	94,543	94,183	94,378	94,587	94,572	94,524	37	15,111
2012			87,260	82,744	86,560	86,667	86,271	86,330	86,483	86,567	86,519	44	16,942
2013				73,670	72,528	71,494	72,145	71,714	72,148	72,318	71,948	49	7,749
2014					80,111	82,461	83,637	83,844	83,539	83,824	83,525	442	8,773
2015						76,637	76,400	76,559	74,723	74,978	74,673	483	7,750
2016							60,105	60,931	62,391	61,723	61,735	442	6,892
2017								59,167	67,978	70,365	70,064	1,822	7,385
2018									62,961	68,526	69,832	3,129	7,596
2019										64,306	72,772	2,765	6,970
2020											109,033	16,218	9,003
										Total	794,625


Homeowners (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year	Unaudited
	2011		2012	2013	2014	2015	2016	2017	2018	2019	2020
2011	$	71,668	89,963	91,718	92,185	93,312	93,720	94,007	94,412	94,458	94,452
2012			69,056	79,584	82,720	84,250	85,196	85,562	85,642	85,897	85,899
2013				50,664	65,528	67,838	69,775	71,776	72,197	72,433	72,446
2014					61,561	76,007	79,751	81,664	82,583	82,836	82,831
2015						52,589	70,078	72,202	72,927	74,079	74,052
2016							42,252	57,333	59,546	60,082	61,187
2017								45,466	63,290	67,193	67,767
2018									49,430	64,137	65,348
2019										49,680	67,631
2020											83,838
										Total	755,451
						All outstanding liabilities before 2011, net of reinsurance					4,985
					Liabilities for loss and loss expenses, net of reinsurance						44,159


E&S Casualty Lines (in thousands, except for claim counts)
Incurred Loss and Allocated Loss Expenses, Net of Reinsurance													As of December 31, 2020
Accident Year					Unaudited								IBNR	Cumulative Number of Reported Claims
	2011		2012		2013	2014	2015	2016	2017	2018	2019	2020
2011	$	8,127	$	7,102	9,853	12,207	10,273	9,652	10,228	12,119	11,554	13,344	408	1,337
2012			42,367		42,621	43,175	46,149	46,165	45,988	46,444	44,622	44,348	2,126	2,055
2013					55,468	60,309	67,099	69,112	67,647	68,972	68,451	68,029	13,032	2,299
2014						55,316	63,505	69,929	71,719	71,206	71,153	70,846	2,352	2,101
2015							75,498	76,432	82,404	90,488	90,355	90,126	12,518	2,844
2016								94,451	96,416	104,655	105,120	104,730	25,507	2,925
2017									91,438	95,783	99,866	99,395	26,778	2,727
2018										98,324	103,004	103,184	41,204	2,637
2019											117,087	118,298	78,482	2,278
2020												103,872	90,970	1,138
											Total	816,172


E&S Casualty Lines (in thousands)
Cumulative Paid Loss and Allocated Loss Expenses, Net of Reinsurance
Accident Year					Unaudited
	2011		2012		2013	2014	2015	2016	2017	2018	2019	2020
2011	$	—	$	806	3,200	6,445	9,954	9,912	10,256	9,819	9,604	10,744
2012			3,722		7,914	16,430	25,064	32,343	36,278	38,298	39,832	40,615
2013					2,715	9,470	21,980	35,200	46,108	51,142	54,974	55,988
2014						2,353	12,234	25,571	43,877	53,780	60,092	64,698
2015							3,036	13,057	29,389	50,712	64,529	71,421
2016								3,720	16,195	33,950	56,581	69,448
2017									5,057	14,672	34,179	53,238
2018										5,509	21,337	39,174
2019											4,422	17,812
2020												3,695
											Total	426,833
							All outstanding liabilities before 2011, net of reinsurance					121
							Liabilities for loss and loss expenses, net of reinsurance					389,460

In 2011, the Parent purchased Mesa Underwriters Specialty Insurance Company ("MUSIC"), a wholly-owned E&S Lines subsidiary of Montpelier Re Holdings, Ltd. Under the terms of the purchase agreement, the Parent acquired net loss and loss reserves amounting to approximately $15 million. All development on this acquired business was fully reinsured as of the acquisition date.


(in thousands)	December 31, 2020
Net outstanding liabilities:
Standard Commercial Lines
General liability	$	1,380,902
Workers compensation	828,146
Commercial automobile	630,512
Businessowners' policies	91,419
Commercial property	74,182
Other Standard Commercial Lines	16,359
Total Standard Commercial Lines net outstanding liabilities	3,021,520

Standard Personal Lines
Personal automobile	94,237
Homeowners	44,159
Other Standard Personal Lines	10,751
Total Standard Personal Lines net outstanding liabilities	149,147

E&S Lines
Casualty lines	389,460
Property lines	16,085
Total E&S Lines net outstanding liabilities	405,545

Total liabilities for unpaid loss and loss expenses, net of reinsurance	3,576,212

Reinsurance recoverable on unpaid claims:
Standard Commercial Lines
General liability	215,136
Workers compensation	210,450
Commercial automobile	11,611
Businessowners' policies	6,849
Commercial property	21,760
Other Standard Commercial Lines	2,853
Total Standard Commercial Lines reinsurance recoverable on unpaid loss	468,659

Standard Personal Lines
Personal automobile	42,403
Homeowners	847
Other Standard Personal Lines	29,589
Total Standard Personal Lines reinsurance recoverable on unpaid loss	72,839

E&S Lines
Casualty lines	12,195
Property lines	576
Total E&S Lines reinsurance recoverable on unpaid loss	12,771

Total reinsurance recoverable on unpaid loss	554,269

Unallocated loss expenses	129,874

Total gross liability for unpaid loss and loss expenses	$	4,260,355

(f) The table below reflects the historical average annual percentage payout of incurred claims by age. For example, the general liability line of business averages payout of 6.3% of its ultimate losses in the first year, 12.2% in the second year, and so forth. The following is supplementary information about average historical claims duration as of December 31, 2020:


Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance
Years	1	2	3	4	5	6	7	8	9	10
General liability	6.3%	12.2	15.7	17.0	14.9	9.8	6.0	5.1	2.0	1.8
Workers compensation	21.8	25.6	13.5	8.1	4.3	3.6	3.5	2.0	1.6	1.2
Commercial automobile	37.5	17.3	14.1	12.7	10.0	4.6	1.6	0.8	0.9	0.3
Businessowners’ policies	48.6	19.4	8.5	8.9	6.7	3.7	1.5	0.2	0.2	0.2
Commercial property	70.0	25.7	2.8	1.0	0.4	—	0.1	0.1	0.1	0.1
Personal automobile	58.4	18.8	9.6	6.7	4.2	1.3	0.5	0.2	0.2	0.1
Homeowners	71.9	20.4	3.3	1.7	1.7	0.3	0.1	0.1	0.1	0.3
E&S Lines - casualty	4.1	12.0	17.4	21.7	13.5	9.0	7.2	3.5	2.0	2.0