Loss and Loss Adjustment Expenses (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Development Tables of Incurred and Paid Losses and Allocated Loss Adjustment Expenses Net of Reinsurance

	Incurred Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance																				As of
	For the Years Ended December 31,																				December 31, 2020
	(Dollars in thousands)																				Total IBNR
																					Plus
																					Expected		Cumulative
																					Development		Number of
Accident	Unaudited (1)																				on Reported		Claims
Year	2011		2012		2013		2014		2015		2016		2017		2018		2019		2020		Claims		Reported
2011	$	196,384	$	199,522	$	199,163	$	198,213	$	195,262	$	192,988	$	191,126	$	189,327	$	188,226	$	188,264	$	5,198		6,044
2012		—		222,549		222,075		212,738		193,515		184,460		182,859		180,387		178,586		177,547		6,419		5,749
2013		—		—		241,810		241,811		233,656		220,457		214,701		210,588		209,184		207,304		7,762		5,766
2014		—		—		—		268,846		268,846		249,097		235,058		226,933		218,386		212,417		5,468		5,839
2015		—		—		—		—		262,573		262,573		252,514		235,471		220,965		211,758		6,717		5,516
2016		—		—		—		—		—		250,491		250,491		241,406		218,005		209,214		6,843		5,393
2017		—		—		—		—		—		—		244,094		244,098		234,587		220,096		8,066		5,211
2018		—		—		—		—		—		—		—		250,487		250,487		235,641		16,057		5,467
2019		—		—		—		—		—		—		—		—		241,344		241,344		16,609		5,199
2020		—		—		—		—		—		—		—		—		—		220,710		8,491		4,170
																	Total		$	2,124,295	$	87,630

	Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance
	For the Years Ended December 31,
	(Dollars in thousands)

Accident	Unaudited (1)																				Claim
Year	2011		2012		2013		2014		2015		2016		2017		2018		2019		2020		Frequency (2)
2011	$	53,329	$	111,029	$	140,831	$	153,968	$	161,639	$	165,967	$	167,757	$	169,994	$	170,785	$	171,583		22.82
2012		—		50,579		107,467		133,658		149,161		154,553		157,207		159,807		161,014		162,588		18.73
2013		—		—		51,396		119,507		150,304		165,994		172,479		177,724		180,614		182,465		16.55
2014		—		—		—		53,060		119,820		153,320		169,736		180,683		186,129		191,394		14.99
2015		—		—		—		—		54,141		121,599		151,818		170,461		182,053		185,657		14.25
2016		—		—		—		—		—		52,238		115,713		143,016		156,861		166,887		14.23
2017		—		—		—		—		—		—		56,951		122,552		151,427		166,448		14.68
2018		—		—		—		—		—		—		—		62,061		126,057		152,328		15.20
2019		—		—		—		—		—		—		—		—		58,883		120,512		15.21
2020		—		—		—		—		—		—		—		—		—		50,113		13.25
																	Total			1,549,975
All outstanding liabilities before 2011, net of reinsurance																				80,533
Liabilities for loss and loss adjustment expenses, net of reinsurance																				654,854

(1) Data presented for these calendar years is required supplementary information, which is unaudited.
(2) Frequency, as calculated above, refers to reported claims divided by gross premium earned.

Summary of Average Annual Percentage Payout of Incurred Losses by Age Net of Reinsurance for Worker's Compensation and General Liability

The average annual percentage payout of incurred losses by age, net of reinsurance, for workers’ compensation and general liability as of December 31, 2020 is summarized below. Since workers’ compensation has long payout periods, the table below shows less than 100% in the years disclosed. This is required supplementary information, which is unaudited.

Average Annual Percentage Payout of Incurred Losses by Age, Net of Reinsurance (Unaudited)
Year 1	Year 2	Year 3	Year 4	Year 5	Year 6	Year 7	Year 8	Year 9	Year 10
25.6%	30.2%	14.1%	7.6%	4.3%	2.1%	1.6%	0.9%	0.7%	0.4%

Reconciliation of Beginning and Ending Reserve Balances, Net of Related Amounts Recoverable from Reinsurers

The following table provides a reconciliation of the beginning and ending reserve balances, net of related amounts recoverable from reinsurers, for 2020, 2019 and 2018:

	Year Ended December 31,
	2020			2019			2018
	(in thousands)
Balance, beginning of period	$	772,887		$	798,409		$	771,845
Less amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses		95,343			107,216			84,889
Net balance, beginning of period		677,544			691,193			686,956
Add incurred related to:
Current accident year		220,710			241,344			250,487
Prior accident years		(63,484	)		(65,002	)		(45,596	)
Total incurred		157,226			176,342			204,891
Less paid related to:
Current accident year		50,113			58,883			62,061
Prior accident years		129,803			131,108			138,593
Total paid		179,916			189,991			200,654
Net balance, end of period		654,854			677,544			691,193
Add amounts recoverable from reinsurers on unpaid loss and loss adjustment expenses		105,707			95,343			107,216
Balance, end of period	$	760,561		$	772,887		$	798,409

Summary Exposures to Various Asbestos Related Claims

The following table details our exposures to various asbestos related claims:

	Year Ended December 31,
	2020			2019			2018
	(in thousands)
Reserves for loss and LAE at beginning of year	$	1,323		$	1,555		$	1,748
Incurred losses and LAE during the current year		(936	)		(183	)		108
Loss and LAE payments		(69	)		(49	)		(301	)
Reserves for loss and LAE at end of year	$	318		$	1,323		$	1,555