Loss And Loss Adjustment Expense Reserves (Tables)

12 Months Ended

Dec. 31, 2022

Insurance [Abstract]

Activity in Loss and Loss Adjustment Expense Reserves

Activity in the loss and LAE reserves is summarized as follows:

(millions)	2022		2021		2020
Balance at January 1	$	26,164.1	$	20,265.8	$	18,105.4
Less reinsurance recoverables on unpaid losses	4,733.6		3,798.2		3,212.2
Net balance at January 1	21,430.5		16,467.6		14,893.2
Net loss and loss adjustment expense reserves acquired1	0		729.2		0
Total beginning reserves	21,430.5		17,196.8		14,893.2
Incurred related to:
Current year	38,209.0		33,632.3		24,926.5
Prior years	(86.3)		(4.7)		195.3
Total incurred	38,122.7		33,627.6		25,121.8
Paid related to:
Current year	23,542.9		20,561.1		15,584.4
Prior years	11,210.2		8,832.8		7,963.0
Total paid	34,753.1		29,393.9		23,547.4
Net balance at December 31	24,800.1		21,430.5		16,467.6
Plus reinsurance recoverables on unpaid losses	5,559.2		4,733.6		3,798.2
Balance at December 31	$	30,359.3	$	26,164.1	$	20,265.8

1 Net reserves acquired in Protective Insurance acquisition.

Short-duration Insurance Contracts, Claims Development

Only 2022 is audited; all prior years are considered required supplementary information and, therefore, are unaudited. Expected development on our case reserves is excluded from the IBNR reserves on our vehicle businesses, as discussed above. For the Property business and the Commercial Lines other business, the IBNR reserves include expected case development based on the methodology used in establishing the case reserves for that segment. The cumulative number of incurred claims are based on accident coverages (e.g., bodily injury, collision, comprehensive, personal injury protection, property damage) related to opened claims. Coverage counts related to claims closed without payment are excluded from the cumulative number of incurred claims.

Personal Lines - Agency - Liability
($ in millions)											As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance											December 31, 2022
	For the years ended December 31,										Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20181		20191		20201		20211		2022
2018	$	5,141.8	$	5,182.1	$	5,192.7	$	5,238.7	$	5,180.2	$	0.4	856,575
2019			5,885.0		5,886.9		5,918.2		5,959.9		115.3		916,390
2020					5,433.8		5,405.4		5,385.7		135.8		756,738
2021							6,716.4		6,861.8		327.1		882,143
2022									7,076.9		1,172.6		821,852
							Total		$	30,464.5
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20181		20191		20201		20211		2022
2018	$	2,378.0	$	4,028.7	$	4,635.0	$	4,940.6	$	5,084.1
2019			2,715.2		4,533.2		5,272.8		5,626.6
2020					2,383.0		4,112.2		4,796.8
2021							2,855.4		5,239.4
2022									3,018.8
							Total		$	23,765.7
	All outstanding liabilities before 2018, net of reinsurance1								92.4
	Liabilities for claims and claim adjustment expenses, net of reinsurance								$	6,791.2

1 Required supplementary information (unaudited)

Personal Lines - Agency - Physical Damage
($ in millions)											As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance											December 31, 2022
	For the years ended December 31,										Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20181		20191		20201		20211		2022
2018	$	2,819.0	$	2,822.6	$	2,821.7	$	2,818.9	$	2,824.2	$	(0.5)	1,695,512
2019			3,277.9		3,254.7		3,261.1		3,259.0		(9.8)		1,878,833
2020					3,328.5		3,319.8		3,327.3		(4.5)		1,784,348
2021							4,708.3		4,624.3		(12.0)		2,103,531
2022									5,429.4		(254.6)		2,006,468
							Total		$	19,464.2
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20181		20191		20201		20211		2022
2018	$	2,769.1	$	2,827.4	$	2,819.9	$	2,819.5	$	2,821.2
2019			3,242.5		3,259.2		3,255.9		3,260.9
2020					3,250.1		3,322.5		3,323.0
2021							4,438.1		4,620.9
2022									5,176.2
							Total		$	19,202.2
	All outstanding liabilities before 2018, net of reinsurance1								(0.5)
	Liabilities for claims and claim adjustment expenses, net of reinsurance								$	261.5

1 Required supplementary information (unaudited)

Personal Lines - Direct - Liability
($ in millions)											As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance											December 31, 2022
	For the years ended December 31,										Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20181		20191		20201		20211		2022
2018	$	4,904.8	$	4,980.9	$	5,003.2	$	5,052.5	$	5,003.2	$	0.5	871,247
2019			5,756.5		5,811.7		5,837.9		5,870.0		95.6		957,707
2020					5,356.9		5,322.7		5,301.5		125.5		789,775
2021							6,964.7		7,180.3		318.2		976,925
2022									7,563.4		1,173.0		951,894
							Total		$	30,918.4
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20181		20191		20201		20211		2022
2018	$	2,235.1	$	3,863.5	$	4,481.7	$	4,787.7	$	4,919.5
2019			2,630.3		4,452.5		5,218.8		5,568.8
2020					2,301.3		4,018.7		4,721.4
2021							2,915.0		5,460.5
2022									3,131.8
							Total		$	23,802.0
	All outstanding liabilities before 2018, net of reinsurance1								70.8
	Liabilities for claims and claim adjustment expenses, net of reinsurance								$	7,187.2

1 Required supplementary information (unaudited)

Personal Lines - Direct - Physical Damage
($ in millions)											As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance											December 31, 2022
	For the years ended December 31,										Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20181		20191		20201		20211		2022
2018	$	3,202.3	$	3,181.9	$	3,182.0	$	3,179.3	$	3,186.4	$	0.9	2,070,287
2019			3,787.9		3,737.8		3,749.6		3,747.9		(9.8)		2,272,135
2020					3,775.6		3,753.3		3,765.9		(6.8)		2,138,359
2021							5,752.3		5,568.2		(30.1)		2,600,641
2022									6,613.3		(398.9)		2,602,301
							Total		$	22,881.7
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20181		20191		20201		20211		2022
2018	$	3,170.0	$	3,193.8	$	3,183.0	$	3,182.6	$	3,183.1
2019			3,782.6		3,751.3		3,746.8		3,750.9
2020					3,720.0		3,765.9		3,762.2
2021							5,421.9		5,578.7
2022									6,325.7
							Total		$	22,600.6
	All outstanding liabilities before 2018, net of reinsurance1								3.6
	Liabilities for claims and claim adjustment expenses, net of reinsurance								$	284.7

1 Required supplementary information (unaudited)

Commercial Lines - Liability
($ in millions)											As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance											December 31, 2022
	For the years ended December 31,										Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20181		20191		20201		20211		2022
2018	$	1,880.4	$	1,913.7	$	1,976.2	$	1,971.4	$	1,966.0	$	6.1	119,869
2019			2,301.1		2,370.9		2,426.3		2,434.4		50.9		136,232
2020					2,335.7		2,388.8		2,418.9		91.6		117,890
2021							3,446.6		3,527.3		268.2		155,226
2022									4,526.1		892.9		186,665
							Total		$	14,872.7
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20181		20191		20201		20211		2022
2018	$	401.4	$	979.9	$	1,392.3	$	1,666.8	$	1,818.0
2019			474.8		1,184.4		1,684.5		2,037.5
2020					440.8		1,110.4		1,628.9
2021							573.6		1,545.9
2022									749.2
							Total		$	7,779.5
	All outstanding liabilities before 2018, net of reinsurance1								83.8
	Liabilities for claims and claim adjustment expenses, net of reinsurance								$	7,177.0

1 Required supplementary information (unaudited)

Commercial Lines - Physical Damage
($ in millions)											As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance											December 31, 2022
	For the years ended December 31,										Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20181		20191		20201		20211		2022
2018	$	528.7	$	528.3	$	526.3	$	525.6	$	525.6	$	0	93,304
2019			633.1		628.3		626.6		625.9		(1.4)		99,494
2020					631.8		624.9		622.0		(1.6)		99,578
2021							920.9		909.8		(5.5)		121,853
2022									1,314.9		(13.8)		152,929
							Total		$	3,998.2
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20181		20191		20201		20211		2022
2018	$	467.6	$	524.8	$	524.9	$	525.4	$	525.0
2019			561.1		625.1		624.8		625.3
2020					540.6		621.8		620.4
2021							764.2		903.1
2022									1,114.0
							Total		$	3,787.8
	All outstanding liabilities before 2018, net of reinsurance1								0.8
	Liabilities for claims and claim adjustment expenses, net of reinsurance								$	211.2

1 Required supplementary information (unaudited)

Commercial Lines - Other
($ in millions)																					As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance																					December 31, 2022
	For the years ended December 31,																				Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20131		20141		20151		20161		20171		20181		20191		20201		20211		2022
2013	$	66.4	$	68.1	$	65.3	$	75.4	$	81.6	$	77.9	$	78.9	$	78.9	$	78.9	$	79.4	$	4.3	8,981
2014			74.9		70.0		68.3		70.5		70.7		69.4		70.7		70.9		70.4		3.5		9,226
2015					51.2		45.4		46.1		48.3		47.0		44.8		45.1		44.6		3.5		9,525
2016							51.8		43.3		41.0		41.5		40.2		40.1		40.0		3.0		7,647
2017									62.6		54.6		51.1		48.8		46.2		48.0		4.6		17,675
2018											81.5		81.3		76.7		77.0		76.5		7.6		15,440
2019													80.7		83.1		85.4		88.3		12.8		10,664
2020															75.0		80.7		81.9		17.7		9,437
2021																	84.1		87.3		30.6		9,264
2022																			84.0		43.0		6,974
																	Total		$	700.4
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20131		20141		20151		20161		20171		20181		20191		20201		20211		2022
2013	$	13.7	$	30.6	$	43.6	$	55.6	$	61.9	$	66.9	$	68.9	$	70.8	$	71.7	$	72.9
2014			18.6		33.9		44.3		51.1		56.9		59.0		61.1		64.2		65.0
2015					6.5		18.1		26.5		30.9		33.9		36.1		37.1		37.8
2016							8.5		20.9		27.0		30.6		32.7		33.8		35.0
2017									9.6		24.4		30.8		34.5		36.9		39.7
2018											17.6		39.6		49.5		56.7		61.7
2019													20.0		42.4		56.0		64.6
2020															15.8		38.6		52.2
2021																	16.9		39.6
2022																			18.4
																	Total		$	486.9
					All outstanding liabilities before 2013, net of reinsurance1														29.0
					Liabilities for claims and claim adjustment expenses, net of reinsurance														$	242.5

1 Required supplementary information (unaudited)

Property Business
($ in millions)											As of
Incurred Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance											December 31, 2022
	For the years ended December 31,										Total of IBNR Liabilities Plus Expected Development on Reported Claims		Cumulative Number of Incurred Claim Counts
Accident Year	20181		20191		20201		20211		2022
2018	$	839.0	$	845.2	$	845.4	$	846.5	$	848.0	$	9.4	63,814
2019			971.7		965.2		962.8		965.8		0.6		73,056
2020					1,223.5		1,246.8		1,260.9		23.6		88,680
2021							1,539.6		1,516.3		77.9		89,348
2022									1,664.6		403.8		82,748
							Total		$	6,255.6
Cumulative Paid Claims and Allocated Claim Adjustment Expenses, Net of Reinsurance
	For the years ended December 31,
Accident Year	20181		20191		20201		20211		2022
2018	$	595.9	$	781.2	$	812.6	$	826.6	$	834.1
2019			708.0		930.4		950.5		959.3
2020					832.5		1,141.2		1,210.7
2021							1,035.4		1,374.5
2022									1,041.7
							Total		$	5,420.3
	All outstanding liabilities before 2018, net of reinsurance1								4.4
	Liabilities for claims and claim adjustment expenses, net of reinsurance								$	839.7

1 Required supplementary information (unaudited)

Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability

The following table reconciles the net incurred and paid claims development tables to the liability for claims and claim adjustment expenses:

(millions)	2022		2021
Net outstanding liabilities
Personal Lines
Agency, Liability	$	6,791.2	$	6,274.3
Agency, Physical Damage	261.5		277.6
Direct, Liability	7,187.2		6,373.2
Direct, Physical Damage	284.7		322.3
Commercial Lines
Liability	7,177.0		5,381.1
Physical Damage	211.2		163.5
Other	242.5		229.8
Property	839.7		650.5
Other business	108.9		62.6
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	23,103.9		19,734.9
Reinsurance recoverables on unpaid claims
Personal Lines
Agency, Liability	894.1		916.9
Agency, Physical Damage	0		0
Direct, Liability	1,485.4		1,472.7
Direct, Physical Damage	0		0
Commercial Lines
Liability	1,273.7		1,266.4
Physical Damage	0.5		2.4
Other	204.6		202.0
Property	1,068.1		370.0
Other business	559.0		463.8
Total reinsurance recoverables on unpaid claims	5,485.4		4,694.2
Unallocated claims adjustment expense related to:
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	1,696.2		1,695.6
Reinsurance recoverables on unpaid claims	73.8		39.4
Total gross liability for unpaid claims and claim adjustment expense	$	30,359.3	$	26,164.1

Short-duration Insurance Contracts, Schedule of Historical Claims Duration

The following table shows the average historical claims duration as of December 31, 2022:

(Required Supplementary Information - Unaudited)
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance	Years
	1	2	3	4	5
Personal Lines
Agency, Liability	43.8%	32.4%	12.3%	5.9%	2.8%
Agency, Physical Damage	97.0	2.4	(0.1)	0.1	0.1
Direct, Liability	42.7	33.0	12.9	6.0	2.6
Direct, Physical Damage	98.0	1.2	(0.2)	0.1	0
Commercial Lines
Liability	17.7	28.3	21.0	14.3	7.7
Physical Damage	86.2	12.7	(0.1)	0.1	(0.1)
Other	20.8	26.1	15.4	10.4	6.9
Property	67.4	23.0	3.9	1.3	0.9