Fair Value Measurements (Fair Value Hierarchy For Assets Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	$ 12,132	$ 13,022
Separate accounts taxable fixed maturities	892	959
Total	22,845	25,349
Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	6,869	7,497
States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	4,622	5,095
Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	234	273
United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	191	123
Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	183	8
Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	33	26
Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	57	64
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	191	123
Total	9,702	11,049
Level 1 | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 1 | States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 1 | Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 1 | United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	191	123
Level 1 | Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 1 | Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 1 | Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	57	64
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	11,941	12,899
Total	13,143	14,300
Level 2 | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	6,869	7,497
Level 2 | States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	4,622	5,095
Level 2 | Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	234	273
Level 2 | United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 2 | Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	183	8
Level 2 | Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	33	26
Level 2 | Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	0	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Total	0	0
Level 3 | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 3 | States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 3 | Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 3 | United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 3 | Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 3 | Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of fixed maturities	0	0
Level 3 | Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	0	0
Equity Securities | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	9,454	10,862
Equity Securities | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	387	453
Equity Securities | Level 1 | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	9,454	10,862
Equity Securities | Level 1 | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	0	0
Equity Securities | Level 2 | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	0	0
Equity Securities | Level 2 | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	387	453
Equity Securities | Level 3 | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	0	0
Equity Securities | Level 3 | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	0	0
Taxable Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	815	948
Taxable Fixed Maturities | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	0	0
Taxable Fixed Maturities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	815	948
Taxable Fixed Maturities | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	$ 0	$ 0