Revenue Recognition and Deferred Revenue (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2022 USD ($)
Contract with Customer, Liability, Revenue Recognized		$ 1	$ 1
Revenue from Contract with Customer, Excluding Assessed Tax	$ 15	7	39		$ 22
Contract with Customer, Receivable, after Allowance for Credit Loss	11		11			$ 7
Contract with Customer, Asset, after Allowance for Credit Loss	9		9			5
Contract with Customer, Liability	1		1			$ 1
Contract with Customer, Performance Obligation Satisfied in Previous Period	5	5
Employer Stop Loss
Revenue from Contract with Customer, Excluding Assessed Tax	3	2	9		7
Affinity Products
Revenue from Contract with Customer, Excluding Assessed Tax	6	5	16		$ 14
Commercial Auto
Revenue from Contract with Customer, Excluding Assessed Tax	4	0	10	$ 0
Product and Service, Other
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2	$ 0	$ 4	$ 0
Minimum [Member]
Employee Stop Loss Time When Base Commissions Recognized Begin and End In Months	17
Maximum [Member]
Employee Stop Loss Time When Base Commissions Recognized Begin and End In Months	21