Investments - Available-for-sale Securities in Gross Unrealized Loss Position (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Gross Unrealized Losses [Abstract]
Total, Estimated Fair Value	$ 26,363	$ 6,065
Total, Gross Unrealized Losses	2,842	112
Fixed maturity securities
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	25,746	5,695
Less than 12 Months, Gross Unrealized Losses	2,728	92
12 Months or Longer, Estimated Fair Value	617	370
12 Months or Longer, Gross Unrealized Losses	114	20
Total, Estimated Fair Value	26,363	6,065
Total, Gross Unrealized Losses	2,842	112
Corporate and Other Bonds
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	14,827	2,389
Less than 12 Months, Gross Unrealized Losses	1,366	48
12 Months or Longer, Estimated Fair Value	322	136
12 Months or Longer, Gross Unrealized Losses	74	8
Total, Estimated Fair Value	15,149	2,525
Total, Gross Unrealized Losses	1,440	56
States, municipalities and political subdivisions
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	4,121	730
Less than 12 Months, Gross Unrealized Losses	666	14
12 Months or Longer, Estimated Fair Value	32
12 Months or Longer, Gross Unrealized Losses	10
Total, Estimated Fair Value	4,153	730
Total, Gross Unrealized Losses	676	14
Residential mortgage-backed
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	2,374	1,043
Less than 12 Months, Gross Unrealized Losses	305	8
12 Months or Longer, Estimated Fair Value	3
12 Months or Longer, Gross Unrealized Losses
Total, Estimated Fair Value	2,377	1,043
Total, Gross Unrealized Losses	305	8
Commercial mortgage-backed
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	1,552	527
Less than 12 Months, Gross Unrealized Losses	143	7
12 Months or Longer, Estimated Fair Value	149	167
12 Months or Longer, Gross Unrealized Losses	21	12
Total, Estimated Fair Value	1,701	694
Total, Gross Unrealized Losses	164	19
Other asset-backed
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	2,354	840
Less than 12 Months, Gross Unrealized Losses	214	10
12 Months or Longer, Estimated Fair Value	85	62
12 Months or Longer, Gross Unrealized Losses	6
Total, Estimated Fair Value	2,439	902
Total, Gross Unrealized Losses	220	10
Total asset-backed
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	6,280	2,410
Less than 12 Months, Gross Unrealized Losses	662	25
12 Months or Longer, Estimated Fair Value	237	229
12 Months or Longer, Gross Unrealized Losses	27	12
Total, Estimated Fair Value	6,517	2,639
Total, Gross Unrealized Losses	689	37
U.S. Treasury and obligations of government-sponsored enterprises
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	82	69
Less than 12 Months, Gross Unrealized Losses	6	3
12 Months or Longer, Estimated Fair Value	3	5
12 Months or Longer, Gross Unrealized Losses	1
Total, Estimated Fair Value	85	74
Total, Gross Unrealized Losses	7	3
Foreign government
Gross Unrealized Losses [Abstract]
Less than 12 Months, Estimated Fair Value	436	97
Less than 12 Months, Gross Unrealized Losses	28	2
12 Months or Longer, Estimated Fair Value	23
12 Months or Longer, Gross Unrealized Losses	2
Total, Estimated Fair Value	459	97
Total, Gross Unrealized Losses	$ 30	$ 2