Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Fixed maturity securities:
Fixed maturity securities	$ 39,385	$ 44,380
Equity securities:
Equity securities	898	1,035
Short term and other	967	1,872
Total assets	41,250	47,287
Other liabilities	(41)	12
Total liabilities	(41)	12
Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	22,325	24,852
States, municipalities and political subdivisions
Fixed maturity securities:
Fixed maturity securities	9,638	11,943
Asset-backed
Fixed maturity securities:
Fixed maturity securities	7,422	7,585
Common Stock
Equity securities:
Equity securities	222	233
Non-redeemable preferred stock
Equity securities:
Equity securities	676	802
Level 1
Fixed maturity securities:
Fixed maturity securities	118	140
Equity securities:
Equity securities	247	285
Short term and other	932	1,798
Total assets	1,297	2,223
Other liabilities	0	0
Total liabilities	0	0
Level 1 | Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	118	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	188	220
Level 1 | Non-redeemable preferred stock
Equity securities:
Equity securities	59	65
Level 2
Fixed maturity securities:
Fixed maturity securities	37,734	42,691
Equity securities:
Equity securities	604	721
Short term and other	35	74
Total assets	38,373	43,486
Other liabilities	(41)	12
Total liabilities	(41)	12
Level 2 | Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	21,361	23,775
Level 2 | States, municipalities and political subdivisions
Fixed maturity securities:
Fixed maturity securities	9,592	11,887
Level 2 | Asset-backed
Fixed maturity securities:
Fixed maturity securities	6,781	7,029
Level 2 | Common Stock
Equity securities:
Equity securities	0	0
Level 2 | Non-redeemable preferred stock
Equity securities:
Equity securities	604	721
Level 3
Fixed maturity securities:
Fixed maturity securities	1,533	1,549
Equity securities:
Equity securities	47	29
Short term and other	0	0
Total assets	1,580	1,578
Other liabilities	0	0
Total liabilities	0	0
Level 3 | Corporate and other bonds
Fixed maturity securities:
Fixed maturity securities	846	937
Level 3 | States, municipalities and political subdivisions
Fixed maturity securities:
Fixed maturity securities	46	56
Level 3 | Asset-backed
Fixed maturity securities:
Fixed maturity securities	641	556
Level 3 | Common Stock
Equity securities:
Equity securities	34	13
Level 3 | Non-redeemable preferred stock
Equity securities:
Equity securities	$ 13	$ 16