Liabilities for Outstanding Claims, Losses and Loss Adjustment Expenses (Tables)

12 Months Ended

Dec. 31, 2022

Insurance [Abstract]

Schedule of Liability for Unpaid Losses and Loss Adjustment Expenses

The table below provides a reconciliation of the gross beginning and ending reserve for unpaid losses and loss adjustment expenses.

YEARS ENDED DECEMBER 31	2022			2021			2020
(in millions)
Gross reserve for losses and LAE, beginning of year	$	6,447.6		$	6,024.0		$	5,654.4
Reinsurance recoverable on unpaid losses		1,693.8			1,641.6			1,574.8
Net loss and LAE reserves, beginning of year		4,753.8			4,382.4			4,079.6
Net incurred losses and LAE in respect of losses    occurring in:
Current year		3,656.0			3,205.3			2,877.8
Prior years		(32.6	)		(71.1	)		(32.6	)
Total incurred losses and LAE		3,623.4			3,134.2			2,845.2
Net payments of losses and LAE in respect of losses    occurring in:
Current year		1,578.9			1,464.1			1,347.7
Prior years		1,534.3			1,298.7			1,194.7
Total payments		3,113.2			2,762.8			2,542.4
Net reserve for losses and LAE, end of year		5,264.0			4,753.8			4,382.4
Reinsurance recoverable on unpaid losses		1,748.6			1,693.8			1,641.6
Gross reserve for losses and LAE, end of year	$	7,012.6		$	6,447.6		$	6,024.0

Schedule of (Favorable)/Unfavorable Loss and LAE Reserve Development

The following table provides a summary of (favorable) unfavorable loss and LAE reserve development.

YEARS ENDED DECEMBER 31	2022			2021			2020
(in millions)
Core Commercial	$	(27.6	)	$	(27.5	)	$	(27.3	)
Specialty		(28.2	)		(18.5	)		(10.5	)
Personal Lines		22.0			(26.1	)		1.0
Other		1.2			1.0			4.2
Total loss and LAE reserve development, including    catastrophes	$	(32.6	)	$	(71.1	)	$	(32.6	)

Schedule of Carried Reserves

The table below summarizes the gross, ceded and net reserve for losses and LAE and reconciles to the incurred claims development in the following section. Within the Core Commercial segment, commercial multiple peril includes small commercial umbrella policies sold as an endorsement, and general liability and umbrella - occurrence which includes workers' compensation excess coverages.

YEARS ENDED DECEMBER 31	2022							2021
(in millions)	Gross		Ceded			Net		Gross		Ceded			Net
Commercial multiple peril	$	1,609.1	$	(185.2	)	$	1,423.9	$	1,378.5	$	(153.2	)	$	1,225.3
Workers’ compensation		719.1		(125.2	)		593.9		681.2		(113.9	)		567.3
Commercial automobile liability		469.7		(21.8	)		447.9		467.0		(23.1	)		443.9
General liability and umbrella - occurrence		418.7		(121.8	)		296.9		363.7		(89.5	)		274.2
Other core commercial		134.3		(54.2	)		80.1		100.6		(29.6	)		71.0
Total Core Commercial		3,350.9		(508.2	)		2,842.7		2,991.0		(409.3	)		2,581.7
Specialty property & casualty		820.6		(278.8	)		541.8		798.6		(287.5	)		511.1
General liability - claims made		381.1		(18.7	)		362.4		345.9		(18.6	)		327.3
Other specialty		396.4		(66.5	)		329.9		377.5		(82.7	)		294.8
Total Specialty		1,598.1		(364.0	)		1,234.1		1,522.0		(388.8	)		1,133.2
Personal automobile liability		1,566.7		(820.6	)		746.1		1,560.0		(838.4	)		721.6
Homeowners		312.3		(2.8	)		309.5		238.5		(4.0	)		234.5
Other personal		119.1		(1.6	)		117.5		69.9		(1.2	)		68.7
Total Personal Lines		1,998.1		(825.0	)		1,173.1		1,868.4		(843.6	)		1,024.8
Total Other		65.5		(51.4	)		14.1		66.2		(52.1	)		14.1
Total loss and LAE reserves	$	7,012.6	$	(1,748.6	)	$	5,264.0	$	6,447.6	$	(1,693.8	)	$	4,753.8

Schedule of Incurred Claims Development

Core Commercial - commercial multiple peril
($ in millions)																	As of
Incurred Losses and ALAE, Net of Reinsurance																	December 31, 2022
YEARS ENDED DECEMBER 31,																			Cumulative
																			Incurred
Accident	2015		2016		2017		2018		2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2015	$	398.1	$	412.9	$	418.6	$	421.9	$	419.0	$	414.0	$	410.1	$	408.3	$	10.6		14,497
2016				398.2		402.5		401.0		400.0		400.1		396.7		397.2		8.3		14,428
2017						473.9		481.1		487.5		491.5		494.0		493.6		17.4		15,359
2018								511.1		495.6		489.5		490.6		495.8		24.2		15,864
2019										520.2		527.0		533.1		542.6		44.8		14,948
2020												562.1		546.7		531.5		84.1		13,066
2021														673.5		658.7		130.9		14,753
2022																748.1		351.1		12,094
Total															$	4,275.8
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2015		2016		2017		2018		2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022
2015	$	152.9	$	241.0	$	289.6	$	329.6	$	358.5	$	372.7	$	379.6	$	384.6
2016				128.7		215.2		261.9		306.8		331.8		347.7		365.4
2017						157.2		264.1		328.8		377.6		414.5		435.6
2018								165.7		274.1		326.4		362.9		403.6
2019										156.5		288.5		348.7		396.3
2020												200.8		318.6		364.2
2021														245.1		392.6
2022																198.2
Total																2,940.5
Total reserves for 2015 – 2022 accident years (incurred - paid)																1,335.3
Total reserves for 2014 and prior accident years																67.8
Unallocated loss adjustment expense																20.8
Net reserves at December 31, 2022															$	1,423.9

Core Commercial - workers' compensation
($ in millions)																					As of
Incurred Losses and ALAE, Net of Reinsurance																					December 31, 2022
YEARS ENDED DECEMBER 31,																							Cumulative
																							Incurred
Accident	2013		2014		2015		2016		2017		2018		2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2013	$	133.0	$	134.0	$	126.0	$	120.1	$	121.0	$	121.4	$	121.1	$	119.4	$	118.9	$	116.2	$	6.1		9,178
2014				143.5		138.0		125.8		124.3		123.1		120.7		118.2		116.4		112.9		7.5		8,807
2015						157.0		136.0		132.1		125.8		122.2		119.0		116.3		113.8		10.5		8,911
2016								158.9		152.8		139.9		133.5		128.3		124.9		122.3		10.0		12,811
2017										159.6		148.7		139.9		136.7		132.4		129.6		11.0		13,415
2018												165.2		161.3		152.6		150.8		149.2		14.4		14,905
2019														170.5		165.0		162.9		163.2		16.7		15,307
2020																167.1		166.8		150.6		24.2		11,904
2021																		178.5		180.8		30.9		14,040
2022																				198.5		64.6		14,269
Total																			$	1,437.1
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2013		2014		2015		2016		2017		2018		2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022
2013	$	24.0	$	58.0	$	78.9	$	87.9	$	94.8	$	98.2	$	101.2	$	102.6	$	104.0	$	104.5
2014				25.7		58.5		75.3		85.0		89.8		93.7		96.2		97.6		98.5
2015						24.2		55.0		72.2		81.8		86.2		89.1		91.2		93.2
2016								29.2		67.0		84.4		93.3		97.2		100.1		102.1
2017										28.5		63.7		82.0		92.7		99.0		102.6
2018												32.2		72.0		91.7		104.2		112.0
2019														30.4		75.7		102.4		116.2
2020																28.8		71.4		91.8
2021																		40.6		85.3
2022																				41.4
Total																				947.6
Total reserves for 2013 – 2022 accident years (incurred - paid)																				489.5
Total reserves for 2012 and prior accident years																				85.6
Unallocated loss adjustment expense and other																				18.8
Net reserves at December 31, 2022																			$	593.9

Core Commercial - commercial automobile liability
($ in millions)															As of
Incurred Losses and ALAE, Net of Reinsurance															December 31, 2022
YEARS ENDED DECEMBER 31,																	Cumulative
																	Incurred
Accident	2016		2017		2018		2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2016	$	144.5	$	144.9	$	151.4	$	161.6	$	159.5	$	160.8	$	163.3	$	—		10,944
2017				146.3		155.6		164.3		169.4		175.6		176.0		1.8		10,910
2018						170.1		157.6		162.9		171.5	176.1			6.0		10,613
2019								161.0		167.9		169.7		174.6		15.1		9,787
2020										153.2		141.5		140.2		34.0		5,895
2021												154.1		156.5		63.0		6,066
2022													157.5			100.1		5,374
Total													$	1,144.2
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2016		2017		2018		2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022
2016	$	26.1	$	56.5	$	92.0	$	125.1	$	137.0	$	143.8	$	152.0
2017				24.9		64.8		95.5		125.8		144.4		160.9
2018						26.8		52.7		83.2		114.5		142.7
2019								27.1		64.5		94.8		126.5
2020										21.0		42.1		71.4
2021												17.7		45.2
2022														18.9
Total														717.6
Total reserves for 2016 – 2022 accident years (incurred - paid)														426.6
Total reserves for 2015 and prior accident years														16.4
Unallocated loss adjustment expense														4.9
Net reserves at December 31, 2022													$	447.9

Core Commercial - general liability and umbrella - occurrence
($ in millions)																					As of
Incurred Losses and ALAE, Net of Reinsurance																					December 31, 2022
YEARS ENDED DECEMBER 31,																							Cumulative
																							Incurred
Accident	2013		2014		2015		2016		2017		2018		2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2013	$	52.1	$	44.4	$	41.5	$	50.4	$	46.9	$	42.5	$	40.1	$	39.6	$	39.0	$	38.6	$	1.9		1,458
2014				70.7		48.9		57.9		60.8		53.8		54.0		53.4		54.0		54.0		3.5		1,442
2015						66.6		57.9		58.6		53.8		52.1		50.5		49.1		45.5		3.2		1,303
2016								58.5		61.0		57.8		55.8		53.7		54.5		54.2		5.5		1,199
2017										58.2		67.1		66.3		63.0		62.9		61.0		8.4		1,027
2018												58.8		61.1		60.3		63.3		63.2		13.5		952
2019														58.9		60.0		60.3		69.3		15.8		827
2020																56.2		58.9		53.4		29.1		518
2021																		58.3		70.0		41.0		473
2022																				63.3		50.5		395
Total																			$	572.5
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2013		2014		2015		2016		2017		2018		2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022
2013	$	1.1	$	5.3	$	12.7	$	21.7	$	28.6	$	32.7	$	34.1	$	34.9	$	35.3	$	35.3
2014				1.6		7.9		17.2		30.3		38.2		45.5		46.0		47.4		48.4
2015						1.4		7.5		14.1		25.5		32.6		37.3		38.3		40.7
2016								0.7		7.3		14.8		25.3		31.7		34.4		38.7
2017										2.3		9.0		19.3		27.1		33.9		42.6
2018												1.0		4.4		18.8		27.2		38.1
2019														4.3		8.7		16.5		28.2
2020																2.1		9.2		11.9
2021																		1.5		6.6
2022																				0.4
Total																				290.9
Total reserves for 2013 – 2022 accident years (incurred - paid)																				281.6
Total reserves for 2012 and prior accident years																				11.9
Unallocated loss adjustment expense and other																				3.4
Net reserves at December 31, 2022																			$	296.9

Specialty property & casualty
($ in millions)															As of
Incurred Losses and ALAE, Net of Reinsurance															December 31, 2022
YEARS ENDED DECEMBER 31,																	Cumulative
																	Incurred
Accident	2016		2017		2018		2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2016	$	157.9	$	152.4	$	153.4	$	154.1	$	156.6	$	157.3	$	158.9	$	5.4		6,473
2017				189.6		185.3		190.1		193.9		195.6		199.1		10.1		6,862
2018						193.0		194.1		193.7		190.2		191.1		13.6		6,440
2019								212.2		209.4		225.7		237.1		24.0		6,496
2020										181.1		170.8		164.9		35.1		5,232
2021												202.9		213.9		63.0		5,897
2022														218.3		110.3		5,175
Total													$	1,383.3
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2016		2017		2018		2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022
2016	$	40.5	$	75.1	$	95.3	$	117.1	$	126.9	$	134.4	$	143.7
2017				55.5		102.6		125.9		138.7		155.6		168.5
2018						56.0		107.9		124.9		140.3		158.6
2019								71.5		113.9		136.5		164.9
2020										40.4		84.0		101.2
2021												59.2		106.6
2022														60.7
Total														904.2
Total reserves for 2016 – 2022 accident years (incurred - paid)														479.1
Total reserves for 2015 and prior accident years														39.2
Unallocated loss adjustment expense														23.5
Net reserves at December 31, 2022													$	541.8

Specialty - general liability - claims made
($ in millions)															As of
Incurred Losses and ALAE, Net of Reinsurance															December 31, 2022
YEARS ENDED DECEMBER 31,																	Cumulative
																	Incurred
Accident	2016		2017		2018		2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2016	$	99.5	$	98.6	$	95.1	$	88.4	$	94.0	$	94.0	$	97.4	$	1.5		974
2017				99.1		100.6		96.1		94.1		92.5		93.6		1.6		1,067
2018						112.2		117.8		121.2		121.7		121.6		5.8		1,176
2019								119.8		119.5		125.6		127.6		12.9		1,258
2020										137.3		134.2		123.3		22.3		1,379
2021												148.2		144.8		54.7		1,372
2022														162.3		99.0		2,108
Total													$	870.6
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2016		2017		2018		2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		Unaudited		2022
2016	$	10.8	$	42.4	$	65.3	$	74.3	$	79.3	$	85.2	$	92.0
2017				12.1		40.9		65.5		74.8		81.0		86.3
2018						14.4		50.3		78.9		93.6		102.9
2019								16.5		53.3		77.0		95.4
2020										16.8		50.6		75.0
2021												15.8		49.9
2022														18.1
Total														519.6
Total reserves for 2016 – 2022 accident years (incurred - paid)														351.0
Total reserves for 2015 and prior accident years														5.3
Unallocated loss adjustment expense														6.1
Net reserves at December 31, 2022													$	362.4

Personal automobile liability
($ in millions)											As of
Incurred Losses and ALAE, Net of Reinsurance											December 31, 2022
YEARS ENDED DECEMBER 31,													Cumulative
													Incurred
Accident	2018		2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2018	$	394.2	$	395.3	$	400.3	$	406.7	$	409.3	$	6.5		43,092
2019				431.2		431.8		436.1		438.9		14.5		42,402
2020						378.0		347.0		312.3		34.4		26,334
2021								407.2		411.6		84.3		30,164
2022										441.9		195.1		29,366
Total									$	2,014.0
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2018		2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		Unaudited		2022
2018	$	121.7	$	237.2	$	307.4	$	353.1	$	382.8
2019				131.0		262.2		336.6		385.1
2020						95.9		179.2		231.8
2021								106.4		225.9
2022										117.2
Total										1,342.8
Total reserves for 2018 – 2022 accident years (incurred - paid)										671.2
Total reserves for 2017 and prior accident years										57.3
Unallocated loss adjustment expense										17.6
Net reserves at December 31, 2022									$	746.1

Homeowners
($ in millions)									As of
Incurred Losses and ALAE, Net of Reinsurance									December 31, 2022
YEARS ENDED DECEMBER 31,											Cumulative
											Incurred
Accident	2019		2020		2021						Claim
Year	Unaudited		Unaudited		Unaudited		2022		IBNR		Count
2019	$	344.5	$	345.3	$	342.1	$	340.7		2.9		33,747
2020				418.8		423.3		424.9		4.3		35,294
2021						461.4		489.9		18.9		38,925
2022								548.5		141.5		29,556
Total							$	1,804.0
Cumulative Paid Losses and ALAE, Net of Reinsurance
YEARS ENDED DECEMBER 31,
Accident	2019		2020		2021
Year	Unaudited		Unaudited		Unaudited		2022
2019	$	234.7	$	311.7	$	322.5	$	329.2
2020				281.5		387.7		408.1
2021						306.9		449.1
2022								324.1
Total								1,510.5
Total reserves for 2019 – 2022 accident years (incurred - paid)								293.5
Total reserves for 2018 and prior accident years								11.9
Unallocated loss adjustment expense								4.1
Net reserves at December 31, 2022							$	309.5

Computation of Historical Claims on Paid and Incurred Claims Data, Net of Reinsurance

The following table is information about average historical claims duration as of December 31, 2022. The table is computed based on the paid and incurred claims data, net of reinsurance, for the accident years presented in the preceding claims development tables.

Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance:
Unaudited
	1			2			3			4			5			6			7			8			9			10
Core Commercial - commercial multiple peril		33.2	%		22.3	%		11.2	%		9.4	%		7.3	%		3.9	%		3.1	%		1.2	%
Core Commercial - workers' compensation		21.3	%		27.9	%		14.9	%		8.2	%		4.5	%		2.8	%		2.1	%		1.4	%		1.0	%		0.4	%
Core Commercial - commercial automobile liability		14.2	%		18.3	%		19.0	%		18.3	%		11.3	%		6.8	%		5.0	%
Core Commercial - general liability and umbrella - occurrence		2.8	%		10.2	%		15.1	%		19.2	%		14.8	%		10.7	%		3.7	%		3.3	%		1.5	%		0.0	%
Specialty property & casualty		27.5	%		23.2	%		10.7	%		10.0	%		8.1	%		5.6	%		5.8	%
Specialty - general liability - claims made		12.1	%		28.7	%		22.4	%		11.4	%		6.4	%		5.9	%		7.0	%
Personal automobile liability		28.5	%		28.5	%		17.0	%		11.1	%		7.3	%
Homeowners		64.2	%		25.5	%		4.0	%		2.0	%