Reinsurance (Tables)

3 Months Ended

Mar. 31, 2023

Reinsurance Disclosures [Abstract]

Reinsurance Recoverable, Credit Quality Indicator [Table Text Block]

Reinsurance Recoverables by Credit Quality Indicator
	As of March 31, 2023								As of December 31, 2022
	Property and Casualty		Group Benefits		Corporate		Total		Property and Casualty		Group Benefits		Corporate		Total
A.M. Best Financial Strength Rating
A++	$	2,166	$	—	$	—	$	2,166	$	2,094	$	—	$	—	$	2,094
A+	2,031		241		252		2,524		2,169		239		259		2,667
A	816		1		—		817		763		1		—		764
A-	83		6		—		89		79		6		—		85
B++	611		—		3		614		616		—		2		618
Below B++	20		—		—		20		20		—		—		20
Total Rated by A.M. Best	5,727		248		255		6,230		5,741		246		261		6,248
Mandatory (Assigned) and Voluntary Risk Pools	217		—		—		217		218		—		—		218
Captives	307		—		—		307		319		—		—		319
Other not rated companies	275		6		—		281		279		5		—		284
Gross Reinsurance Recoverables	6,526		254		255		7,035		6,557		251		261		7,069
Allowance for uncollectible reinsurance	(102)		(1)		(2)		(105)		(102)		(1)		(2)		(105)
Net Reinsurance Recoverables	$	6,424	$	253	$	253	$	6,930	$	6,455	$	250	$	259	$	6,964

Reinsurance Recoverable, Allowance for Credit Loss [Table Text Block]

Allowance for Uncollectible Reinsurance for the Three Months Ended
	March 31, 2023								March 31, 2022
	Property and Casualty		Group Benefits		Corporate		Total		Property and Casualty		Group Benefits		Corporate		Total
Beginning allowance for uncollectible reinsurance	$	102	$	1	$	2	$	105	$	96	$	1	$	2	$	99
Beginning allowance for disputed amounts	60		—		—		60		54		—		—		54
Beginning ACL	42		1		2		45		42		1		2		45
Current period provision (release)	2		—		—		2		(2)		—		—		(2)
Ending ACL	44		1		2		47		40		1		2		43
Ending allowance for disputed amounts	58		—		—		58		56		—		—		56
Ending allowance for uncollectible reinsurance	$	102	$	1	$	2	$	105	$	96	$	1	$	2	$	99