Loss and Loss Adjustment Expenses (Tables)

12 Months Ended

Dec. 31, 2022

Insurance [Abstract]

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, 2022
	(Dollars in thousands)																				Total IBNR
																					Plus
																					Expected				Cumulative
																					Development				Number of
Accident	Unaudited (1)																				on Reported				Claims
Year	2013		2014		2015		2016		2017		2018		2019		2020		2021		2022		Claims				Reported
2013	$	241,810	$	241,811	$	233,656	$	220,457	$	214,701	$	210,588	$	209,184	$	207,304	$	205,421	$	204,026		$	6,435			5,768
2014		—		268,846		268,846		249,097		235,058		226,933		218,386		212,417		210,811		210,096			4,510			5,841
2015		—		—		262,573		262,573		252,514		235,471		220,965		211,758		207,929		207,086			4,415			5,516
2016		—		—		—		250,491		250,491		241,406		218,005		209,214		202,820		201,604			4,452			5,393
2017		—		—		—		—		244,094		244,098		234,587		220,096		211,964		208,360			4,939			5,212
2018		—		—		—		—		—		250,487		250,487		235,641		217,369		208,517			5,268			5,471
2019		—		—		—		—		—		—		241,344		241,344		227,246		214,123			8,550			5,218
2020		—		—		—		—		—		—		—		220,710		220,710		214,500			17,039			4,387
2021		—		—		—		—		—		—		—		—		222,715		222,715			(5,162	)		4,273
2022		—		—		—		—		—		—		—		—		—		192,907			6,863			3,886
																	Total		$	2,083,934		$	57,308

	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	2013		2014		2015		2016		2017		2018		2019		2020		2021		2022		Frequency (2)
2013	$	51,396	$	119,507	$	150,304	$	165,994	$	172,479	$	177,724	$	180,614	$	182,465	$	183,365	$	184,500		16.56
2014		—		53,060		119,820		153,320		169,736		180,683		186,129		191,394		192,169		193,192		14.99
2015		—		—		54,141		121,599		151,818		170,461		182,053		185,657		188,145		189,339		14.25
2016		—		—		—		52,238		115,713		143,016		156,860		166,887		172,133		174,134		14.23
2017		—		—		—		—		56,951		122,552		151,427		166,448		175,733		183,696		14.68
2018		—		—		—		—		—		62,061		126,057		152,328		172,423		181,081		15.21
2019		—		—		—		—		—		—		58,884		120,512		154,391		168,448		15.26
2020		—		—		—		—		—		—		—		50,113		109,882		137,411		13.94
2021		—		—		—		—		—		—		—		—		52,292		130,288		14.92
2022		—		—		—		—		—		—		—		—		—		50,954		13.77
																	Total			1,593,043
All outstanding liabilities before 2013, net of reinsurance																				92,591
Liabilities for loss and loss adjustment expenses, net of reinsurance																				583,482
(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, 2022 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
26.0%	31.5%	14.3%	7.8%	4.6%	2.7%	1.5%	0.6%	0.5%	0.6%

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 2022, 2021 and 2020:

	Year Ended December 31,
	2022			2021			2020
	(in thousands)
Balance, beginning of period	$	745,278		$	760,561		$	772,887
Less amounts recoverable from reinsurers    on unpaid loss and loss adjustment expenses		119,266			105,707			95,343
Net balance, beginning of period		626,012			654,854			677,544
Add incurred related to:
Current accident year		192,907			222,715			220,710
Prior accident years		(40,591	)		(61,917	)		(63,484	)
Total incurred		152,316			160,798			157,226
Less paid related to:
Current accident year		50,954			52,292			50,113
Prior accident years		143,892			137,348			129,803
Total paid		194,846			189,640			179,916
Net balance, end of period		583,482			626,012			654,854
Add amounts recoverable from reinsurers    on unpaid loss and loss adjustment expenses		112,555			119,266			105,707
Balance, end of period	$	696,037		$	745,278		$	760,561

Summary Exposures to Various Asbestos Related Claims

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

	Year Ended December 31,
	2022			2021			2020
	(in thousands)
Reserves for loss and LAE at beginning of year	$	260		$	318		$	1,323
Incurred losses and LAE during the current year		(2	)		(44	)		(936	)
Loss and LAE payments		(10	)		(14	)		(69	)
Reserves for loss and LAE at end of year	$	248		$	260		$	318