Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fixed maturity securities:
Fixed maturity securities	$ 37,627	$ 44,380
Equity securities:
Equity securities	674	1,035
Short term and other	1,679	1,872
Total assets	39,980	47,287
Other liabilities	1	12
Total liabilities	1	12
Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	22,117	24,852
States, municipalities and political subdivisions
Fixed maturity securities:
Fixed maturity securities	8,317	11,943
Asset-backed
Fixed maturity securities:
Fixed maturity securities	7,193	7,585
Common Stock
Equity securities:
Equity securities	185	233
Non-redeemable preferred stock
Equity securities:
Equity securities	489	802
Level 1
Fixed maturity securities:
Fixed maturity securities	120	140
Equity securities:
Equity securities	204	285
Short term and other	1,608	1,798
Total assets	1,932	2,223
Other liabilities	0	0
Total liabilities	0	0
Level 1 | Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	120	140
Level 1 | States, municipalities and political subdivisions
Fixed maturity securities:
Fixed maturity securities	0	0
Level 1 | Asset-backed
Fixed maturity securities:
Fixed maturity securities	0	0
Level 1 | Common Stock
Equity securities:
Equity securities	150	220
Level 1 | Non-redeemable preferred stock
Equity securities:
Equity securities	54	65
Level 2
Fixed maturity securities:
Fixed maturity securities	35,866	42,691
Equity securities:
Equity securities	435	721
Short term and other	71	74
Total assets	36,372	43,486
Other liabilities	1	12
Total liabilities	1	12
Level 2 | Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	21,187	23,775
Level 2 | States, municipalities and political subdivisions
Fixed maturity securities:
Fixed maturity securities	8,274	11,887
Level 2 | Asset-backed
Fixed maturity securities:
Fixed maturity securities	6,405	7,029
Level 2 | Common Stock
Equity securities:
Equity securities	0	0
Level 2 | Non-redeemable preferred stock
Equity securities:
Equity securities	435	721
Level 3
Fixed maturity securities:
Fixed maturity securities	1,641	1,549
Equity securities:
Equity securities	35	29
Short term and other	0	0
Total assets	1,676	1,578
Other liabilities	0	0
Total liabilities	0	0
Level 3 | Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	810	937
Level 3 | States, municipalities and political subdivisions
Fixed maturity securities:
Fixed maturity securities	43	56
Level 3 | Asset-backed
Fixed maturity securities:
Fixed maturity securities	788	556
Level 3 | Common Stock
Equity securities:
Equity securities	35	13
Level 3 | Non-redeemable preferred stock
Equity securities:
Equity securities	$ 0	$ 16