Reinsurance (Tables)

12 Months Ended

Dec. 31, 2023

Insurance [Abstract]

Reinsurance Recoverable, Credit Quality Indicator

Reinsurance Recoverables by Credit Quality Indicator
	As of December 31, 2023								As of December 31, 2022
	P&C		Group Benefits		Corporate		Total		P&C		Group Benefits		Corporate		Total
AM Best Financial Strength Rating
A++	$	2,398	$	—	$	—	$	2,398	$	2,094	$	—	$	—	$	2,094
A+	2,030		251		241		2,522		2,169		239		259		2,667
A	810		1		—		811		763		1		—		764
A-	653		5		—		658		79		6		—		85
B++	2		—		3		5		616		—		2		618
Below B++	22		—		—		22		20		—		—		20
Total Rated by AM Best	5,915		257		244		6,416		5,741		246		261		6,248
Mandatory (Assigned) and Voluntary Risk Pools	208		—		—		208		218		—		—		218
Captives	353		—		—		353		319		—		—		319
Other not rated companies	226		4		—		230		279		5		—		284
Gross Reinsurance Recoverables	6,702		261		244		7,207		6,557		251		261		7,069
Allowance for uncollectible reinsurance	(100)		(1)		(2)		(103)		(102)		(1)		(2)		(105)
Net Reinsurance Recoverables	$	6,602	$	260	$	242	$	7,104	$	6,455	$	250	$	259	$	6,964

Reinsurance Recoverable, Allowance for Credit Loss

Allowance for Uncollectible Reinsurance
	As of December 31, 2023		As of December 31, 2022		As of December 31, 2021
P&C beginning allowance for uncollectible reinsurance	$	102	$	96	$	105
Beginning allowance for disputed amounts	60		54		53
P&C beginning ACL	42		42		52
Current period provision (release)	3		—		(9)
Current period gross write-offs	(2)		—		(1)
P&C ending ACL	43		42		42
Ending allowance for disputed amounts	57		60		54
P&C ending allowance for uncollectible reinsurance	100		102		96
Group Benefits allowance for uncollectible reinsurance	1		1		1
Corporate allowance for uncollectible reinsurance	2		2		2
Total allowance for uncollectible reinsurance	$	103	$	105	$	99

Property and Casualty Insurance and Group Benefits Revenue

Insurance Revenues

Property and Casualty Insurance Revenue

	For the years ended December 31,
Premiums Written	2023		2022		2021
Direct	$	16,144	$	14,891	$	13,696
Assumed	975		718		631
Ceded	(1,642)		(1,490)		(1,378)
Net	$	15,477	$	14,119	$	12,949
Premiums Earned
Direct	$	15,514	$	14,328	$	13,204
Assumed	826		654		568
Ceded	(1,612)		(1,462)		(1,277)
Net	$	14,728	$	13,520	$	12,495

Group Benefits Revenue

	For the years ended December 31,
	2023		2022		2021
Gross earned premiums, fees and other considerations	$	6,445	$	5,988	$	5,663
Reinsurance assumed	174		175		128
Reinsurance ceded	(104)		(106)		(104)
Net earned premiums, fees and other considerations	$	6,515	$	6,057	$	5,687