Loss and Loss Adjustment Expenses (Tables)

12 Months Ended

Dec. 31, 2023

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, 2023
	(Dollars in thousands)																				Total IBNR
																					Plus
																					Expected				Cumulative
																					Development				Number of
Accident	Unaudited (1)																				on Reported				Claims
Year	2014		2015		2016		2017		2018		2019		2020		2021		2022		2023		Claims				Reported
2014	$	268,846	$	268,846	$	249,097	$	235,058	$	226,933	$	218,386	$	212,417	$	210,811	$	210,096	$	209,210		$	4,097			5,841
2015		—		262,573		262,573		252,514		235,471		220,965		211,758		207,929		207,086		205,556			4,374			5,517
2016		—		—		250,491		250,491		241,406		218,005		209,214		202,820		201,604		198,566			4,691			5,394
2017		—		—		—		244,094		244,098		234,587		220,096		211,964		208,360		206,293			5,324			5,214
2018		—		—		—		—		250,487		250,487		235,641		217,369		208,517		205,001			4,347			5,477
2019		—		—		—		—		—		241,344		241,344		227,246		214,123		206,109			5,672			5,223
2020		—		—		—		—		—		—		220,710		220,710		214,500		207,047			13,909			4,391
2021		—		—		—		—		—		—		—		222,715		222,715		215,232			2,894			4,304
2022		—		—		—		—		—		—		—		—		192,907		192,907			(12,814	)		4,065
2023		—		—		—		—		—		—		—		—		—		189,659			12,433			3,715
																	Total		$	2,035,580		$	44,927

	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	2014		2015		2016		2017		2018		2019		2020		2021		2022		2023		Frequency (2)
2014	$	53,060	$	119,820	$	153,320	$	169,736	$	180,683	$	186,129	$	191,394	$	192,169	$	193,192	$	195,409		14.99
2015		—		54,141		121,599		151,818		170,461		182,053		185,657		188,145		189,339		190,588		14.25
2016		—		—		52,238		115,713		143,016		156,860		166,887		172,133		174,134		178,572		14.23
2017		—		—		—		56,951		122,552		151,427		166,448		175,733		183,696		185,690		14.69
2018		—		—		—		—		62,061		126,057		152,328		172,423		181,081		184,797		15.23
2019		—		—		—		—		—		58,884		120,512		154,391		168,448		176,488		15.28
2020		—		—		—		—		—		—		50,113		109,882		137,411		153,974		13.95
2021		—		—		—		—		—		—		—		52,292		130,288		159,864		15.02
2022		—		—		—		—		—		—		—		—		50,954		110,494		14.40
2023		—		—		—		—		—		—		—		—		—		47,207		13.09
																	Total			1,583,083
All outstanding liabilities before 2014, net of reinsurance																				101,752
Liabilities for loss and loss adjustment expenses, net of reinsurance																				554,248
(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, 2023 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
26.4%	31.7%	14.3%	8.0%	4.8%	2.5%	1.4%	1.1%	0.5%	1.1%

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 2023, 2022 and 2021:

	Year Ended December 31,
	2023			2022			2021
	(in thousands)
Balance, beginning of period	$	696,037		$	745,278		$	760,561
Less amounts recoverable from reinsurers    on unpaid loss and loss adjustment expenses		112,555			119,266			105,707
Net balance, beginning of period		583,482			626,012			654,854
Add incurred related to:
Current accident year		189,659			192,907			222,715
Prior accident years		(41,396	)		(40,591	)		(61,917	)
Total incurred		148,263			152,316			160,798
Less paid related to:
Current accident year		47,207			50,954			52,292
Prior accident years		130,290			143,892			137,348
Total paid		177,497			194,846			189,640
Net balance, end of period		554,248			583,482			626,012
Add amounts recoverable from reinsurers    on unpaid loss and loss adjustment expenses		119,746			112,555			119,266
Balance, end of period	$	673,994		$	696,037		$	745,278

Summary Exposures to Various Asbestos Related Claims

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

	Year Ended December 31,
	2023		2022			2021
	(in thousands)
Reserves for loss and LAE at beginning of year	$	248	$	260		$	318
Incurred losses and LAE during the current year		15		(2	)		(44	)
Loss and LAE payments		47		(10	)		(14	)
Reserves for loss and LAE at end of year	$	310	$	248		$	260